Erratum: Publisher Correction: Current and future global climate impacts resulting from COVID-19

Understanding carbon resilience under public health emergencies: a synthetic difference-in-differences approach

Public health emergencies influence urban carbon emissions, yet an in-depth understanding of deviations between regional emissions under such emergencies and normal levels is lacking. Inspired by the concept of resilience, we introduce the concept of regional carbon resilience and propose four resilience indicators covering periods during and after emergencies. A synthetic difference-in-differences model is employed to compute these indicators, providing a more suitable approach than traditional methods assuming unchanged levels before and after emergencies. Using the COVID-19 pandemic in China as a case study, focusing on the power and industry sectors, we find that over 40% regions exhibit strong resilience (> 0.9). Average in-resilience (0.764 and 0.783) is higher than post-resilience (0.534 and 0.598) in both sectors, indicating lower resilience during than after emergencies. Significant differences in resilience performance exist across regions, with Hebei (0.93) and Hangzhou (0.92) as top performers, and Qinghai (0.29) and Guiyang (0.36) as the least resilient. Furthermore, a preliminary correlation analysis identifies 22 factors affecting carbon resilience; higher energy consumption, stronger industrial production, and a healthier regional economy positively contribute to resilience with coefficients over + 0.3, while pandemic severity negatively impacts resilience, with coefficients up to -0.58. These findings provide valuable references for policymaking to achieve carbon neutrality goals.

Deciphering and quantifying nitrate sources and processes in the central Yellow Sea using dual isotopes of nitrate

Anthropogenic activities pose significant challenges to the accumulation of coastal nitrogen (N). Accurate identification of nitrate (NO3-) sources is thus essential for mitigating excessive N in many marginal seas. We investigated the dual isotopes of NO3- in the central Yellow Sea to elucidate the sources and cycling processes of NO3-. The results revealed significant spatial variability in NO3- concentrations among the Yellow Sea Surface Water (YSSW), Changjiang Diluted Water (CDW), Yellow Sea Cold Water Mass (YSCWM), and Taiwan Warm Current Water (TWCW). Stratification played a crucial role in restricting vertical nutrient transport, leading to distinct nutrient sources and concentrations in different water masses. The dual NO3- isotopic signature indicated that atmospheric deposition was the primary source of surface NO3-, contributing approximately 30 % to the NO3- in the YSSW. In the NO3--rich CDW, the heavier δ15N-NO3- and δ18O-NO3- suggested incomplete NO3- assimilation. Organic matter mineralization and water stratification played crucial roles in the accumulation of nutrients within the YSCWM and TWCW. Notably, regenerated NO3- accounted for approximately half of the NO3- stored in the YSCWM. A synthesis of NO3- dual isotope data across the coastal China seas revealed significant spatial and seasonal variations in the N source. The study emphasized the dynamics of coastal NO3- supply, which are shaped by the complex interconnections among marine, terrestrial, and atmospheric processes. Our approach is a feasible method for exploring the origins of N amidst the escalating pressures of anthropogenic nutrient pollution in coastal waters.

The effect of quarantine policy on pollution emission and the usage of private transportation in urban areas

Governmental policies, regulations, and responses to the pandemic can benefit from a better understanding of people's resulting behaviours before, during, and after COVID-19. To avoid the inelasticity and subjectivity of survey datasets, several studies have already used some objective variables like air pollutants to estimate the potential impacts of COVID-19 on the urban transportation system. However, the usage of reactant gases and a narrow time scale might weaken the results somehow. Here, both the objective passenger volume of public transport and the concentration of private traffic emitted black carbon (BC) from 2018 to 2023 were collected/calculated to decipher the potential relationship between public and private traffic during the COVID-19 period. Our results indicated that the commuting patterns of citizens show significant (p < 0.01) different patterns before, during, and after the pandemic. To be specific, public transportation showed a significant (p < 0.01) positive correlation with private transportation before the pandemic. This public transportation was significantly (p < 0.01) affected by the outbreaks of COVID-19, showing a significant (p < 0.01) negative correlation with private transportation. Such impacts of the virus and governmental policy would affect the long-term behaviour of individuals and even affect public transportation usage after the pandemic. Our results also indicated that such behaviour was mainly linked to the governmental restriction policy and would soon be neglected after the cancellation of the restriction policy in China.

Path analysis for controlling climate change in global aviation

The aviation industry's emissions have had a significant impact on global climate change. This study focuses on carbon emission trading schemes, sustainable aviation fuels (SAFs), and hydrogen energy, as vital means for the aviation industry to reduce emissions. To evaluate the climate effects of global routes under four scenarios (24 sub-scenarios) until 2100, this study proposes the Aviation-FAIR (Aviation-Finite Amplitude Impulse Response) method. The findings reveal that while CO2 emissions and concentrations are significant, other emissions, such as N2O and CH4, have a greater effective radiative forcing (ERF) and contribute significantly to climate change. Moreover, SAFs are more effective in mitigating airline pollutant emissions than relying solely on carbon trading schemes. The effectiveness of hydrogen fuel cells may be hindered by technical limitations compared to hydrogen turbine engines. The findings of this study provide reference for the global aviation industry to adopt emission reduction measures.

Abrupt reduction in shipping emission as an inadvertent geoengineering termination shock produces substantial radiative warming

Human activities affect the Earth's climate through modifying the composition of the atmosphere, which then creates radiative forcing that drives climate change. The warming effect of anthropogenic greenhouse gases has been partially balanced by the cooling effect of anthropogenic aerosols. In 2020, fuel regulations abruptly reduced the emission of sulfur dioxide from international shipping by about 80% and created an inadvertent geoengineering termination shock with global impact. Here we estimate the regulation leads to a radiative forcing of + 0.2 ± 0.11 Wm-2 averaged over the global ocean. The amount of radiative forcing could lead to a doubling (or more) of the warming rate in the 2020 s compared with the rate since 1980 with strong spatiotemporal heterogeneity. The warming effect is consistent with the recent observed strong warming in 2023 and expected to make the 2020 s anomalously warm. The forcing is equivalent in magnitude to 80% of the measured increase in planetary heat uptake since 2020. The radiative forcing also has strong hemispheric contrast, which has important implications for precipitation pattern changes. Our result suggests marine cloud brightening may be a viable geoengineering method in temporarily cooling the climate that has its unique challenges due to inherent spatiotemporal heterogeneity.

Unraveling varying spatiotemporal patterns of dengue and associated exposure-response relationships with environmental variables in Southeast Asian countries before and during COVID-19

The enforcement of COVID-19 interventions by diverse governmental bodies, coupled with the indirect impact of COVID-19 on short-term environmental changes (e.g. plant shutdowns lead to lower greenhouse gas emissions), influences the dengue vector. This provides a unique opportunity to investigate the impact of COVID-19 on dengue transmission and generate insights to guide more targeted prevention measures. We aim to compare dengue transmission patterns and the exposure-response relationship of environmental variables and dengue incidence in the pre- and during-COVID-19 to identify variations and assess the impact of COVID-19 on dengue transmission. We initially visualized the overall trend of dengue transmission from 2012-2022, then conducted two quantitative analyses to compare dengue transmission pre-COVID-19 (2017-2019) and during-COVID-19 (2020-2022). These analyses included time series analysis to assess dengue seasonality, and a Distributed Lag Non-linear Model (DLNM) to quantify the exposure-response relationship between environmental variables and dengue incidence. We observed that all subregions in Thailand exhibited remarkable synchrony with a similar annual trend except 2021. Cyclic and seasonal patterns of dengue remained consistent pre- and during-COVID-19. Monthly dengue incidence in three countries varied significantly. Singapore witnessed a notable surge during-COVID-19, particularly from May to August, with cases multiplying several times compared to pre-COVID-19, while seasonality of Malaysia weakened. Exposure-response relationships of dengue and environmental variables show varying degrees of change, notably in Northern Thailand, where the peak relative risk for the maximum temperature-dengue relationship rose from about 3 to 17, and the max RR of overall cumulative association 0-3 months of relative humidity increased from around 5 to 55. Our study is the first to compare dengue transmission patterns and their relationship with environmental variables before and during COVID-19, showing that COVID-19 has affected dengue transmission at both the national and regional level, and has altered the exposure-response relationship between dengue and the environment.

How the COVID-19 pandemic signaled the demise of Antarctic exceptionalism

This paper explores how the COVID-19 pandemic affected science and tourism activities and their governance in the Antarctic and Southern Ocean. The pandemic reduced the ability of Antarctic Treaty Parties to make decisions on policy issues and placed a considerable burden on researchers. Tourism was effectively suspended during the 2020-2021 Antarctic season and heavily reduced in 2021-2022 but rebounded to record levels in 2022-2023. The pandemic stimulated reflection on practices to facilitate dialog, especially through online events. Opportunities arose to integrate innovations developed during the pandemic more permanently into Antarctic practices, in relation to open science, reducing operational greenhouse gas footprints and barriers of access to Antarctic research and facilitating data sharing. However, as well as the long-term impacts arising directly from the pandemic, an assemblage of major geopolitical drivers are also in play and, combined, these signal a considerable weakening of Antarctic exceptionalism in the early Anthropocene.

Arctic/North Atlantic atmospheric variability causes Severe PM10 events in South Korea

Severe PM10 (particulate matter with a diameter of <10 μm) events in South Korea are known to be caused by stable atmospheric circulation conditions related to high-pressure anomalies in the upper troposphere. However, research on why these atmospheric circulation patterns occur is unknown. In this study, we propose new large-scale teleconnection pathways that cause severe PM10 events during the midwinter in South Korea. This study investigated instances of extremely high (EH)-PM10 in South Korea during mid-winter and examined the corresponding atmospheric teleconnection patterns to identify the factors contributing to EH-PM10 events. K-means clustering analysis revealed that EH-PM10 instances were associated with two large-scale teleconnection patterns. Cluster 1 exhibited a wave train pattern originating in the North Atlantic that developed from Eurasia to the Korean Peninsula. Cluster 2 was associated with a wave-like teleconnection pattern from the Barents-Kara Sea to the Korean Peninsula. The Rossby waves, triggered by the North Atlantic and the Arctic, propagated and weakened the surface pressure system. This led to a high-pressure anomaly over the Korean Peninsula, reducing atmospheric ventilation and causing a rapid increase in PM10 concentration within a few days. Furthermore, an experiment involving a linear baroclinic model established that atmospheric forcing in upstream regions has the potential to induce large-scale atmospheric teleconnection patterns, resulting in EH-PM10 cases in South Korea. These findings emphasize the ventilation effect and transport of PM10 concentrations modulated by two large-scale teleconnection patterns originating from the Arctic and North Atlantic, leading to EH-PM10 events in South Korea. Understanding this combined phenomenon may assist in the implementation of emission reduction measures based on the results of short-term forecasts of severe PM10 events.

Carbon dioxide emissions and environmental risks: Long term and short term

The world is currently experiencing the environmental challenge of global warming, necessitating careful planning of carbon dioxide (CO2 ) emissions to deal with this problem. This study examines the environmental challenge posed by CO2 emissions from both a long and short-term perspective. In the long term, despite efforts made by countries, our change-point detection analysis shows that there has been no structural change in CO2 emissions since 1950. Without significant efforts, the carbon budget corresponding to the Paris Agreement's target will be exhausted by 2046. To achieve this target, a significant reduction in global CO2 emissions of 3.22% per year is necessary. In the short term, COVID-19 is thought to have relieved pressure on CO2 emissions. However, this study shows that CO2 emissions quickly returned to normal levels after a brief downturn, and we provide information on the order of CO2 emissions recovery for different sectors.

Rebound and steep increase of international travel after the COVID-19 pandemic: where are we going from here?

The Coronavirus Disease of 2019 caused an unprecedented drop in air travel. Recovery was influenced by infection waves and different infection control measures. International travel entered a rebound phase in 2022, with more growth forecasted. Now it seems the time to reframe tourism linked to flights and considering planetary health aspects.

Air pollution benefits from reduced on-road activity due to COVID-19 in the United States

On-road transportation is one of the largest contributors to air pollution in the United States. The COVID-19 pandemic provided the unintended experiment of reduced on-road emissions' impacts on air pollution due to lockdowns across the United States. Studies have quantified on-road transportation's impact on fine particulate matter (PM2.5)-attributable and ozone (O3)-attributable adverse health outcomes in the United States, and other studies have quantified air pollution-attributable health outcome reductions due to COVID-19-related lockdowns. We aim to quantify the PM2.5-attributable, O3-attributable, and nitrogen dioxide (NO2)-attributable adverse health outcomes from traffic emissions as well as the air pollution benefits due to reduced on-road activity during the pandemic in 2020. We estimate 79,400 (95% CI 46,100-121,000) premature mortalities each year due to on-road-attributable PM2.5, O3, and NO2. We further break down the impacts by pollutant and vehicle types (passenger [PAS] vs. freight [FRT] vehicles). We estimate PAS vehicles to be responsible for 63% of total impacts and FRT vehicles 37%. Nitrogen oxide (NOX) emissions from these vehicles are responsible for 78% of total impacts as it is a precursor for PM2.5 and O3. Utilizing annual vehicle miles traveled reductions in 2020, we estimate that 9,300 (5,500-14,000) deaths from air pollution were avoided in 2020 due to the state-specific reductions in on-road activity across the continental United States. By quantifying the air pollution public health benefits from lockdown-related reductions in on-road emissions, the results from this study stress the need for continued emission mitigation policies, like the U.S. Environmental Protection Agency's (EPA) recently proposed NOX standards for heavy-duty vehicles, to mitigate on-road transportation's public health impact.

COVID-19 perturbation on US air quality and human health impact assessment

The COVID-19 stay-at-home orders issued in the United States caused significant reductions in traffic and economic activities. To understand the pandemic's perturbations on US emissions and impacts on urban air quality, we developed near-real-time bottom-up emission inventories based on publicly available energy and economic datasets, simulated the emission changes in a chemical transport model, and evaluated air quality impacts against various observations. The COVID-19 pandemic affected US emissions across broad-based energy and economic sectors and the impacts persisted to 2021. Compared with 2019 business-as-usual emission scenario, COVID-19 perturbations resulted in annual decreases of 10-15% in emissions of ozone (O3) and fine particle (PM2.5) gas-phase precursors, which are about two to four times larger than long-term annual trends during 2010-2019. While significant COVID-induced reductions in transportation and industrial activities, particularly in April-June 2020, resulted in overall national decreases in air pollutants, meteorological variability across the nation led to local increases or decreases of air pollutants, and mixed air quality changes across the United States between 2019 and 2020. Over a full year (April 2020 to March 2021), COVID-induced emission reductions led to 3-4% decreases in national population-weighted annual fourth maximum of daily maximum 8-h average O3 and annual PM2.5. Assuming these emission reductions could be maintained in the future, the result would be a 4-5% decrease in premature mortality attributable to ambient air pollution, suggesting that continued efforts to mitigate gaseous pollutants from anthropogenic sources can further protect human health from air pollution in the future.

Avoidable heat risk under scenarios of carbon neutrality by mid-century

To prevent anthropogenic warming of the climate system above dangerous thresholds, governments are required by the Paris Agreement to peak global anthropogenic CO2 emissions and to reach a net zero CO2 emissions level (also known as carbon neutrality). Growing concerns are being expressed about the increasing heat stress caused by the interaction of changes in temperature and humidity in the context of global warming. Although much effort has been made to examine future changes in heat stress and associated risks, gaps remain in understanding the quantitative benefits of heat-risk avoidance from carbon-neutral policies, limited by the traditional climate projections from the Coupled Model Intercomparison Project Phase 6 (CMIP6). Here we quantify the avoided heat risk during 2040-2049 under two scenarios of global carbon neutrality by 2060 and 2050, i.e., moderate green (MODGREEN) and strong green (STRGREEN) recovery scenarios, relative to the baseline scenario (FOSSIL), based on multi-model large ensemble climate projections from a new climate model intercomparison project (CovidMIP) that endorsed by CMIP6. We show that global population exposure to extreme heat stress increases by approximately four times its current level during 2040-2049 under the FOSSIL scenario, whereas the heat exposure could be reduced by as much as 12 % and 23 % under the MODGREEN and STRGREEN scenarios, respectively. Moreover, global mean heat-related mortality risk is mitigated by 14 % (24 %) under the MODGREEN (STRGREEN) scenario during 2040-2049 relative to the FOSSIL scenario. Additionally, the aggravating heat risk could be mitigated by around a tenth by achieving carbon neutrality 10 years earlier (2050 versus 2060). In terms of spatial pattern, this heat-risk avoidance from low-carbon policies is typically greater in low-income countries. Our findings assist governments in advancing early climate change mitigation policy-making.

The worldwide COVID-19 lockdown impacts on global secondary inorganic aerosols and radiative budget

Global lockdown measures to prevent the spread of the coronavirus disease 2019 (COVID-19) led to air pollutant emission reductions. While the COVID-19 lockdown impacts on both trace gas and total particulate pollutants have been widely investigated, secondary aerosol formation from trace gases remains unclear. To that end, we quantify the COVID-19 lockdown impacts on NOx and SO2 emissions and sulfate-nitrate-ammonium aerosols using multiconstituent satellite data assimilation and model simulations. We find that anthropogenic emissions over major polluted regions were reduced by 19 to 25% for NOx and 14 to 20% for SO2 during April 2020. These emission reductions led to 8 to 21% decreases in sulfate and nitrate aerosols over highly polluted areas, corresponding to >34% of the observed aerosol optical depth declines and a global aerosol radiative forcing of +0.14 watts per square meter relative to business-as-usual scenario. These results point to the critical importance of secondary aerosol pollutants in quantifying climate impacts of future mitigation measures.

Satellite reveals a steep decline in China's CO2 emissions in early 2022

Response actions to the coronavirus disease 2019 perturbed economies and carbon dioxide (CO2) emissions. The Omicron variant that emerged in 2022 caused more substantial infections than in 2020 and 2021 but it has not yet been ascertained whether Omicron interrupted the temporary post-2021 rebound of CO2 emissions. Here, using satellite nitrogen dioxide observations combined with atmospheric inversion, we show a larger decline in China's CO2 emissions between January and April 2022 than in those months during the first wave of 2020. China's CO2 emissions are estimated to have decreased by 15% (equivalent to -244.3 million metric tons of CO2) during the 2022 lockdown, greater than the 9% reduction during the 2020 lockdown. Omicron affected most of the populated and industrial provinces in 2022, hindering China's CO2 emissions rebound starting from 2021. China's emission variations agreed with downstream CO2 concentration changes, indicating a potential to monitor CO2 emissions by integrating satellite and ground measurements.

Economic development, social media awareness, and technological innovation in biogas sector under climate change in the post-COVID-19 pandemic conditions

After COVID-19, financing for emerging nation reserves in renewable energy bases was deemed a crucial aspect of sustainable development. Investing in biogas energy plants can be highly beneficial for lowering the use of fossil fuels. Using a survey of shareholders, investors, biogas energy professionals, and active social media participants in Pakistan, this study evaluates the intentions of individual investors to invest in biogas energy plants. The primary purpose of this study is to increase investment intent for biogas energy projects following COVID-19. This study focuses on financing biogas energy plants in the post-COVID-19 era and evaluates the research's assumptions using partial least squares structural equation modeling (PLS-SEM). The study employed the technique of purposive sampling to acquire data for this investigation. The results indicate that attitudes, perceived biogas energy benefits, perceived investment attitudes, and supervisory structure evaluations inspire one's propensity to finance biogas vitality plant efforts. The study found a link between eco-friendly responsiveness, monetary benefits, and investors' actions. The aspiration of investors to mark such reserves was set up to be unpretentious by their risk aversion. Conferring to the facts, evaluating the monitoring structure is the critical factor. The previous studies on investment behavior and other forms of pro-environmental intent and action yielded contradictory results. In addition, the regulatory environment was evaluated to see how the theory of planned behavior (TPB) affects financiers' objectives to participate in biogas power plants. The consequences of the study indicate that feelings of pride and discernment of energy expansively affect people's desire to invest in biogas plants. Biogas energy efficacy has little effect on investors' decisions to invest in biogas energy plants. This study offers policymakers practical ideas on enhancing investments in biogas energy plants.

Inter-regional environmental inequality under lasting pandemic exacerbated by residential response

Pandemics greatly affect transportation, economic and household activities and their associated air pollutant emissions. In less affluent regions, household energy use is often the dominant pollution source and is sensitive to the affluence change caused by a persisting pandemic. Air quality studies on COVID-19 have shown declines in pollution levels over industrialized regions as an immediate response to pandemic-caused lockdown and weakened economy. Yet few have considered the response of residential emissions to altered household affluence and energy choice supplemented by social distancing. Here we quantify the potential effects of long-term pandemics on ambient fine particulate matter pollution (PM_2.5) and resulting premature mortality worldwide, by comprehensively considering the changes in transportation, economic production and household energy use. We find that a persisting COVID-like pandemic would reduce the global gross domestic product by 10.9 % and premature mortality related to black carbon, primary organic aerosols and secondary inorganic aerosols by 9.5 %. The global mortality decline would reach 13.0 % had the response of residential emissions been excluded. Among the 13 aggregated regions worldwide, the least affluent regions exhibit the greatest fractional economic losses with no comparable magnitudes of mortality reduction. This is because their weakened affluence would cause switch to more polluting household energy types on top of longer stay-at-home time, largely offsetting the effect of reduced transportation and economic production. International financial, technological and vaccine aids could reduce such environmental inequality.

Carbon Monitor Europe near-real-time daily CO2 emissions for 27 EU countries and the United Kingdom

With the urgent need to implement the EU countries pledges and to monitor the effectiveness of Green Deal plan, Monitoring Reporting and Verification tools are needed to track how emissions are changing for all the sectors. Current official inventories only provide annual estimates of national CO₂ emissions with a lag of 1+ year which do not capture the variations of emissions due to recent shocks including COVID lockdowns and economic rebounds, war in Ukraine. Here we present a near-real-time country-level dataset of daily fossil fuel and cement emissions from January 2019 through December 2021 for 27 EU countries and UK, which called Carbon Monitor Europe. The data are calculated separately for six sectors: power, industry, ground transportation, domestic aviation, international aviation and residential. Daily CO₂ emissions are estimated from a large set of activity data compiled from different sources. The goal of this dataset is to improve the timeliness and temporal resolution of emissions for European countries, to inform the public and decision makers about current emissions changes in Europe.

COVID-19-associated 2020 lockdown: a study on atmospheric black carbon fall impact on human health

The mean mass concentrations of black carbon (BC)_, biomass burning (BC)_bb, and fossil fuel combustion (BC)_ff have been estimated during March-May 2020 (during the COVID-19 outbreak) and March-May 2019 at a semiarid region of Agra over the Indo-Gangetic basin region. The daily mean mass concentration of BC in 2020 and 2019 was 3.9 and 6.9 µg m^-3, respectively. The high monthly mean mass concentration of BC was found to be 4.7, 3.4 and 3.3 µg m^-3 in Mar-2020, Apr-2020, and May-2020, respectively, whereas in Mar-2019, Apr-2019, and May-2019 was 7.7, 7.5 and 5.4 µg m^-3, respectively. The absorption coefficient (b_abs) and absorption angstrom exponent (AAE) of black carbon were calculated. The highest mean AAE was 1.6 in the year 2020 (Mar-May 2020) indicating the dominance of biomass burning. The mean mass concentration of fossil fuel (BC)_ff and biomass burning (BC)_bb is 3.4 and 0.51 µg m^-3, respectively, in 2020 whereas 6.4 and 0.73 µg m^-3, respectively, in 2019. The mean fraction contribution of BC with fossil fuel (BC)_ff was 82.1 ± 13.5% and biomass burning (BC)_bb was 17.9 ± 4.3% in 2020, while in 2019, fossil fuel (BC)_ff was 86.7 ± 13.5% and biomass burning (BC)_bb was 13.3 ± 6.7%. The population-weighted mean concentration of BC, fossil fuel (BC)_ff, and biomass burning (BC)_bb has been calculated. The health risk assessment of BC has been analyzed in the form of attributable relative risk factors and attributed relative risk during the COVID-19 outbreak using AirQ + v.2.0 model. The attributable relative risk factors of BC were 20.6% in 2020 and 29.4% in 2019. The mean attributed relative risk per 10,000,000 populations at 95% confidence interval (CI) due to BC was 184.06 (142.6-225.2) in 2020 and 609.06 (418.3-714.6) in 2019. The low attributed factor and attributed relative risk in 2020 may be attributed to improvements in air quality and a fall in the emission of BC. In 2020, due to the COVID-19 pandemic, the whole country faced the biggest lockdown, ban of the transportation of private vehicles, trains, aircraft, and construction activities, and shut down of the industry leading to a fall in the impact of BC on human health. Overall, this was like a blessing in disguise. This study will help in future planning of mitigation and emission control of air pollutants in large and BC in particular. It only needs a multipronged approach. This study may be like torch bearing to set path for mitigation of impacts of air pollution and improvement of air quality.

eDNA testing reveals surprising findings on fish population dynamics in Thailand

COVID-19, a global health concern, has an effect on all aspects of the economy. The aquaculture and fishing industries were severely harmed as a result of the closures in multiple nations. Regular systems for inventory monitoring, production, and supply were disrupted. Cancellation of programmes for research, fieldwork, sampling, and tagging influences management-required data. For effective species management, fish dispersion assessments are indispensable. However, due to the difficulty of accessing sampling sites and the associated costs, there is frequently a lack of comprehensive information regarding the distribution and abundance of organisms. The COVID-19 prohibition made fish monitoring more problematic. Due to constant pressure, populations of the stone lapping minnow (Garra cambodgiensis), one of Thailand's overfished fish, are rapidly declining. Therefore, eDNA-based monitoring was devised and implemented to reveal the likely dispersal of the species in Thailand prior to and following the lockdown. At 28 locations within the Chao Phraya River Basin, water samples were collected. qPCR was used to determine the presence or absence of G. cambodgiensis in water samples. In 78 of 252 water samples, a wide range of computed copy numbers for G. cambodgiensis eDNA was observed. It was discovered that samples collected in 2021 (after the lockdown) contain a higher concentration of G. cambodgiensis eDNA than samples collected in 2018 or 2019 (prior to the lockdown). The closure appears to be a boon and may result in a substantial restocking of the fish we have studied. Overall, eDNA-based analysis is an extremely promising new survey instrument.

New perspectives and issues in industrial policy for sustainable development: from developmental and entrepreneurial to environmental state

The increasingly acute consequences of the climate crisis, the COVID-19 pandemic, and the energy crisis have put industrial policy back. The papers in this issue examine how different countries implement industrial policy for sustainable development from a variety of perspectives. A successful transition to sustainable development seems to require not only the mix of carrots and sticks but also a right mix of creation versus destruction, as in the case of the creation of renewable businesses and the destruction of fossil-fuel businesses. Furthermore, because institutional diversity and the risk of capture can result in very distinct economic, social, and environmental effects, consideration of heterogeneity at the country and sector levels and coordination of vested interests are essential ingredients for sustainable industrial policies, as shown by the case of industrial policy in France and the two industry cases in India. By contrast, the Amazon Fund case is indicative of the three success elements: multi-stakeholder governance, pay-for-performance funding, and non-reimbursable project financing. These three elements can be summarized as local ownership and accountable governance, provided with both carrots and sticks. The problematic case of urban development driven by the oil industry in Ghana can be criticized in terms of the lack of local ownership of the oil industry, which has led to all rents being monopolized by the absentee class. By comparison, the mixed success of cases of industrial symbiosis in Uganda is attributed to the lack of effective carrots. In sum, industrial policy for sustainable development requires handling well all three types of failure, namely, market, system, and capability failures, because it necessitates building capabilities of involved actors and coordinating actions of agents, in addition to providing optimal incentives to reflect externalities of global public goods. Overall, the shifting focus of industrial policy is consistent with the shift of the role of the state, from developmental to entrepreneurial, and finally to environmental state.

Aerosol demasking enhances climate warming over South Asia

Anthropogenic aerosols mask the climate warming caused by greenhouse gases (GHGs). In the absence of observational constraints, large uncertainties plague the estimates of this masking effect. Here we used the abrupt reduction in anthropogenic emissions observed during the COVID-19 societal slow-down to characterize the aerosol masking effect over South Asia. During this period, the aerosol loading decreased substantially and our observations reveal that the magnitude of this aerosol demasking corresponds to nearly three-fourths of the CO2-induced radiative forcing over South Asia. Concurrent measurements over the northern Indian Ocean unveiled a ~7% increase in the earth's surface-reaching solar radiation (surface brightening). Aerosol-induced atmospheric solar heating decreased by ~0.4 K d-1. Our results reveal that under clear sky conditions, anthropogenic emissions over South Asia lead to nearly 1.4 W m-2 heating at the top of the atmosphere during the period March-May. A complete phase-out of today's fossil fuel combustion to zero-emission renewables would result in rapid aerosol demasking, while the GHGs linger on.

Effects of Coal Metakaolin on the Mechanical Properties and Microstructure of High-belite Sulphoaluminate Cement

The effects of coal metakaolin on the mechanical properties of high-belite sulphoaluminate cement under compressive loading were investigated. The composition and microstructure of hydration products at different hydration times were analyzed by X-ray diffraction and scanning electronic microscopy. The hydration process of blended cement was studied via electrochemical impedance spectroscopy. In particular, replacing a part of cement with CMK (10%, 20%, and 30%) was found to promote the hydration process, to refine the pore size, and to improve the compressive strength of the composite. The best compressive strength of the cement was achieved at a CMK content of 30% after 28 days hydration, being improved by 20.13 MPa, or 1.44 times relative to that of undoped specimens. Furthermore, the compressive strength is shown to correlate with the impedance parameter RCCP, which allows the latter to be used for nondestructive assessment of the compressive strength of blended cement materials.

"I stretch them out as long as possible:" U.S. women's experiences of menstrual product insecurity during the COVID-19 pandemic

BACKGROUND

A growing body of evidence highlights how the COVID-19 pandemic has exacerbated gender inequalities in the US. This resulted in women being more vulnerable to economic insecurity and decreases in their overall well-being. One relevant issue that has been less explored is that of women's menstrual health experiences, including how inconsistent access to menstrual products may negatively impact their daily lives.

METHODS

This qualitative study, conducted from March through May 2021, utilized in-depth interviews that were nested within a national prospective cohort study. The interviews (n = 25) were conducted with a sub-sample of cis-gender women living across the US who had reported challenges accessing products during the first year of the pandemic. The interviews sought to understand the barriers that contributed to experiencing menstrual product insecurity, and related coping mechanisms. Malterud's 'systematic text condensation', an inductive thematic analysis method, was utilized to analyze the qualitative transcripts.

RESULTS

Respondents came from 17 different states across the U.S. Three key themes were identified: financial and physical barriers existed to consistent menstrual product access; a range of coping strategies in response to menstrual product insecurity, including dependence on makeshift and poorer quality materials; and heightened experiences of menstrual-related anxiety and shame, especially regarding the disclosure of their menstruating status to others as a result of inadequate menstrual leak protection.

CONCLUSIONS

Addressing menstrual product insecurity is a critical step for ensuring that all people who menstruate can attain their most basic menstrual health needs. Key recommendations for mitigating the impact of menstrual product insecurity require national and state-level policy reform, such as the inclusion of menstrual products in existing safety net basic needs programs, and the reframing of menstrual products as essential items. Improved education and advocacy are needed to combat menstrual stigma.

Environmentally sustainable smart cities and their converging AI, IoT, and big data technologies and solutions: an integrated approach to an extensive literature review

There have recently been intensive efforts aimed at addressing the challenges of environmental degradation and climate change through the applied innovative solutions of AI, IoT, and Big Data. Given the synergistic potential of these advanced technologies, their convergence is being embraced and leveraged by smart cities in an attempt to make progress toward reaching the environmental targets of sustainable development goals under what has been termed "environmentally sustainable smart cities." This new paradigm of urbanism represents a significant research gap in and of itself. To fill this gap, this study explores the key research trends and driving factors of environmentally sustainable smart cities and maps their thematic evolution. Further, it examines the fragmentation, amalgamation, and transition of their underlying models of urbanism as well as their converging AI, IoT, and Big Data technologies and solutions. It employs and combines bibliometric analysis and evidence synthesis methods. A total of 2,574 documents were collected from the Web of Science database and compartmentalized into three sub-periods: 1991-2015, 2016-2019, and 2020-2021. The results show that environmentally sustainable smart cities are a rapidly growing trend that markedly escalated during the second and third periods-due to the acceleration of the digitalization and decarbonization agendas-thanks to COVID-19 and the rapid advancement of data-driven technologies. The analysis also reveals that, while the overall priority research topics have been dynamic over time-some AI models and techniques and environmental sustainability areas have received more attention than others. The evidence synthesized indicates that the increasing criticism of the fragmentation of smart cities and sustainable cities, the widespread diffusion of the SDGs agenda, and the dominance of advanced ICT have significantly impacted the materialization of environmentally sustainable smart cities, thereby influencing the landscape and dynamics of smart cities. It also suggests that the convergence of AI, IoT, and Big Data technologies provides new approaches to tackling the challenges of environmental sustainability. However, these technologies involve environmental costs and pose ethical risks and regulatory conundrums. The findings can inform scholars and practitioners of the emerging data-driven technology solutions of smart cities, as well as assist policymakers in designing and implementing responsive environmental policies.

Japanese urban household carbon footprints during early-stage COVID-19 pandemic were consistent with those over the past decade

As urbanization accelerates worldwide, substantial energy and services are required to meet the demand from cities, making cities major contributors to adverse environmental consequences. To bridge the knowledge gap in the absence of fine-grained city-level climate protection measures due to data availability and accuracy, this study provides a detailed carbon emission inventory for analyzing the monthly fluctuations based on citizens' daily consumption behaviors. Here, carbon emissions embodied in approximately 500 household consumption items were calculated in 47 prefectural-level cities in Japan from 2011 to June 2021. We analyzed the results considering the regional, seasonal, demand, and emission way-specific aspects, and compared the emission before and during the COVID-19 pandemic. Notably, the carbon footprints during the pandemic were consistent with the previous level despite downtrends in specific categories. This study provides an example of utilizing city-level emission data to improve household green consumption behavior as references for enriching city-level decarbonization paths.

Prioritising Climate Change Mitigation Behaviours and Exploring Public Health Co-Benefits: A Delphi Study

Climate change requires urgent action; however, it can be challenging to identify individual-level behaviours that should be prioritised for maximum impact. The study aimed to prioritise climate change mitigation behaviours according to their impacts on climate change and public health, and to identify associated barriers and facilitators-exploring the impact of observed behaviour shifts associated with COVID-19 in the UK. A three-round Delphi study and expert workshop were conducted: An expert panel rated mitigation behaviours impacted by COVID-19 in relation to their importance regarding health impacts and climate change mitigation using a five-point Likert scale. Consensus on the importance of target behaviours was determined by interquartile ranges. In total, seven target behaviours were prioritised: installing double/triple glazing; installing cavity wall insulation; installing solid wall insulation; moving away from meat/emission heavy diets; reducing the number of cars per household; walking shorter journeys; and reducing day/weekend leisure car journeys. Barriers related to the costs associated with performing behaviours and a lack of complementary policy-regulated subsidies. The target behaviours are consistent with recommendations from previous research. To ensure public uptake, interventions should address behavioural facilitators and barriers, dovetail climate change mitigation with health co-benefits and account for the long-term impacts of COVID-19 on these behaviours.

Research on the impact of COVID-19 on the spatiotemporal distribution of carbon dioxide emissions in China

Since the outbreak of COVID-19 at the end of 2019, the Chinese government has imposed strict control measures on affected cities, which may have impacted the spatial and temporal pattern of carbon dioxide emissions. This paper follows the quantitative analysis method, experimental method, mathematical method, etc., and quantitatively studies the impact of the epidemic on China's carbon emissions. The combination model of ARIMA and BP neural network is used to predict the actual impact of epidemic situation on China's carbon emissions in 2020, and the spatial autocorrelation analysis method is used to analyze the spatial characteristics of China's provincial carbon emissions, which indicate that China's carbon emissions have consistently maintained a growth trend, from 2.05 billion tons in 2005 to 3.89 billion tons in 2019. Furthermore, the growth rate of carbon emissions and the changing trend of the emission intensity are the same, dropping from 12% in 2005 to 3% in 2019. The emission intensity also dropped from 1.1 in 2005 to 0.6 in 2019, indicating that the trend of increasing carbon emissions in northern provinces and Xinjiang changed significantly from 2005 to 2019. The overall carbon emissions of the 30 provinces in 2020 are predicted to be 4.068 billion tons, while the actual energy carbon emissions will be 3.921 billion tons, suggesting that the pandemic significantly reduced carbon emissions. Among affected provinces, carbon emissions from Hubei, Jiangsu, Shandong, Shanghai, and other places changed significantly, from 0.99, 0.25, 0.43, and 76 million tons in 2019 to 0.88, 0.24, 0.42, and 72 million tons in 2020, respectively. The results show a positive spatial correlation between China's provincial carbon emissions; the high-high and bottom-high agglomeration are mainly among the provinces, mainly distributed in North China and East China. Although the pandemic seriously impacts China's carbon emissions, each province's spatial relationship has not changed significantly.

The COVID-19 pandemic in various restriction policy scenarios based on the dynamic social contact rate

The social contact rate has influenced the transmission of COVID-19, with more social contact resulting in more contagion cases. We chose 18 countries with the most confirmed cases in the first 200 days after the Wuhan lockdown. This was the first study using the dynamic social contact rate to simulate the epidemic under diverse restriction policies over 500 days since the COVID-19 outbreak. The developed General Dynamic Model suggested that the probability of contagion ranged from 12.52% to 39.39% in the epidemic. The geometric mean of the social contact rates differed from 18.21% to 96.00% between countries. The restriction policies in developed economies were 3.5 times more efficient than in developing economies. We compare the effectiveness of different policies for disease prevention and discuss the influence of policy adjustment frequency for each country. Maintaining the tightest restriction or alternate tightening and loosening restrictions was recommended, with each having an average 72.45% and 79.78% reduction in maximum active cases, respectively.

Most industrialised countries have peaked carbon dioxide emissions during economic crises through strengthened structural change

As the climate targets tighten and countries are impacted by several crises, understanding how and under which conditions carbon dioxide emissions peak and start declining is gaining importance. We assess the timing of emissions peaks in all major emitters (1965-2019) and the extent to which past economic crises have impacted structural drivers of emissions contributing to emission peaks. We show that in 26 of 28 countries that have peaked emissions, the peak occurred just before or during a recession through the combined effect of lower economic growth (1.5 median percentage points per year) and decreasing energy and/or carbon intensity (0.7) during and after the crisis. In peak-and-decline countries, crises have typically magnified pre-existing improvements in structural change. In non-peaking countries, economic growth was less affected, and structural change effects were weaker or increased emissions. Crises do not automatically trigger peaks but may strengthen ongoing decarbonisation trends through several mechanisms.

Water balance components and climate extremes over Brazil under 1.5 °C and 2.0 °C of global warming scenarios

This work aimed to evaluate changes in water balance components (precipitation, evapotranspiration, and water availability) and precipitation extremes projected under global warming levels (GWLs) of 1.5 °C and 2 °C, in Brazil. An ensemble of eight twenty-first-century projections with the Eta Regional Climate Model and their driving Global Climate Models (CanESM2, HadGEM2-ES, MIROC5, and BESM) were used. Projections of two Representative Concentration Pathway scenarios, RCP4.5 and RCP8.5, considered intermediate and high concentration, respectively, were used. The results indicate that the RCP8.5 scenario under 2 °C GWL is likely to have a higher impact on the water balance components, amplifying trends in drier conditions and increasing the number of consecutive dry days in some regions of Brazil, particularly in the North and Northeast regions. On the other hand, the projections indicate the opposite sign for the South region, with trends toward wetter conditions and significant increases in extreme rainfall. The 0.5 °C difference between the GWLs contributes to intensifying reductions (increases) from 4 to 7% in water availability, mainly in the North-Northeast (South) regions. The projected changes could have serious consequences, such as increases in the number of drought events in hydrographic regions of the Northeast region of Brazil and increases in flood events in the South of the country. The results here presented can contribute to the formulation of adaptive planning strategies aimed at ensuring Brazil's water security towards climate change.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10113-023-02042-1.

Covid-19 and energy sector: Unique opportunity for switching to clean energy

The novel coronavirus (2019-nCoV) was extended to 213 countries globally by August 2021. The world has been threatened by rising infection rates and emerged as the catastrophic event in the field of health triggering the international emergency panic button. COVID-19's sudden arrival wreaked havoc on the world economic picture, particularly in the energy sector. A steep drop in oil prices, as well as an imbalance in energy, was the result of strict travel restrictions, fewer transportation options, and people's fears of a flu pandemic. However, confined mobility and a drop in energy demand coated the environment with a silver line and drowned the nation's economic opportunities. Industrial transport, and not to mention every conventional energy-related thing, is completely devastated, but renewables were immunized. Wind, solar, hydrothermal, hydrogen, biomass-based energy systems were on high gear yielding maximum results in counterbalancing the demand-supply chain. Moreover, the pandemic created an opportunity to showcase the importance of renewable energy and tackle the difficult emergency like now. In addition to this, the mindset of the investors was slowly fading away from conventional fuels and shifting towards renewable energy. However, it is too early to state the booming renewables at the moment, and no idea about its long-time survival. Thus, the present review gives a clear picture of the current status of fossils and renewables, the impact of a pandemic, energy investments, government policy standings, threats, and opportunities, and finally, the key takeaways avoiding energy scarcity in once a lifetime disaster situation.

The long-term dynamic relationship between communicable disease spread, economic prosperity, greenhouse gas emissions, and government health expenditures: preparing for COVID-19-like pandemics

The spread of communicable diseases, such as COVID-19, has a detrimental effect on our socio-economic structure. In a dynamic log-run world, socio-economic and environmental factors interact to spread communicable diseases. We investigated the long-term interdependence of communicable disease spread, economic prosperity, greenhouse gas emissions, and government health expenditures in India's densely populated economy using a variance error correction (VEC) approach. The VEC model was validated using stationarity, cointegration, autocorrelation, heteroscedasticity, and normality tests. Our impulse response and variance decomposition analyses revealed that economic prosperity (GNI) significantly impacts the spread of communicable diseases, greenhouse gas emissions, government health expenditures, and GNI. Current health expenditures can reduce the need for future increases, and the spread of communicable diseases is detrimental to economic growth. Developing economies should prioritize economic growth and health spending to combat pandemics. Simultaneously, the adverse effects of economic prosperity on environmental degradation should be mitigated through policy incentives.

COVID-19 response in Africa: impacts and lessons for environmental management and climate change adaptation

The COVID-19 pandemic adds pressure on Africa; the most vulnerable continent to climate change impacts, threatening the realization of most Sustainable Development Goals (SDGs). The continent is witnessing an increase in intensity and frequency of extreme weather events, and environmental change. The COVID-19 was managed relatively well across in the continent, providing lessons and impetus for environmental management and addressing climate change. This work examines the possible impact of the COVID-19 pandemic on the environment and climate change, analyses its management and draws lessons from it for climate change response in Africa. The data, findings and lessons are drawn from peer reviewed articles and credible grey literature on COVID-19 in Africa. The COVID-19 pandemic spread quickly, causing loss of lives and stagnation of the global economy, overshadowing the current climate crisis. The pandemic was managed through swift response by the top political leadership, research and innovations across Africa providing possible solutions to COVID-19 challenges, and redirection of funds to manage the pandemic. The well-coordinated COVID-19 containment strategy under the African Centers for Disease Control and Prevention increased sharing of resources including data was a success in limiting the spread of the virus. These strategies, among others, proved effective in limiting the spread and impact of COVID-19. The findings provide lessons that stakeholders and policy-makers can leverage in the management of the environment and address climate change. These approaches require solid commitment and practical-oriented leadership.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10668-023-02956-0.

Sustainable development goal 13 and switching priorities: addressing climate change in the context of pandemic recovery efforts

The COVID-19 pandemic has had many deep social and economic impacts that go beyond health issues. One consequence is that the pandemic has made it even harder to mobilize the financial resources needed to pursue SDG 13 (Climate Action) as a whole and to fund climate change mitigation and adaptation efforts in particular. This is especially acute in respect of the efforts to achieve the targets set by the Paris Agreement and by the recent decisions in Glasgow. This paper looks at how the COVID-19 pandemic has accelerated poverty and undermined climate change mitigation and adaptation efforts, as a result of the switches in priorities and funding. Using a review of the recent literature, an analysis of international trends, and a survey among climate scientists, it identifies some of the impacts of the pandemic on climate change mitigation and adaptation efforts and discusses their implications. The findings indicate a decrease in funding to climate change research since the pandemic crisis. The bibliometric analysis reveals that a greater emphasis has been placed on the relationship between COVID-19 and poverty when compared to the interrelations between COVID-19 and climate change. Addressing climate change is as urgent now as it was before the pandemic crisis started, and efforts need to be made to upkeep the levels of funding needed to support research in this field.

The interplay among COVID-19 economic recovery, behavioural changes, and the European Green Deal: An energy-economic modelling perspective

In the EU, COVID-19 and associated policy responses led to economy-wide disruptions and shifts in services demand, with considerable energy-system implications. The European Commission's response paved the way towards enhancing climate ambition through the European Green Deal. Understanding the interactions among environmental, social, and economic dimensions in climate action post-COVID thus emerged as a key challenge. This study disaggregates the implications of climate ambition, speed of economic recovery from COVID-19, and behavioural changes due to pandemic-related measures and/or environmental concerns for EU transition dynamics, over the next decade. It soft-links two large-scale energy-economy models, EU-TIMES and NEMESIS, to shed light on opportunities and challenges related to delivering on the EU's 2030 climate targets. Results indicate that half the effort required to reach the updated 55% emissions reduction target should come from electricity decarbonisation, followed by transport. Alongside a post-COVID return to normal, the European Green Deal may lead to increased carbon prices and fossil-fuel rebounds, but these risks may be mitigated by certain behavioural changes, gains from which in transport energy use would outweigh associated consumption increases in the residential sector. Finally, the EU recovery mechanism could deliver about half the required investments needed to deliver on the 2030 ambition.

CO2 in indoor environments: From environmental and health risk to potential renewable carbon source

In the developed world, individuals spend most of their time indoors. Poor Indoor Air Quality (IAQ) has a wide range of effects on human health. The burden of disease associated with indoor air accounts for millions of premature deaths related to exposure to Indoor Air Pollutants (IAPs). Among them, CO₂ is the most common one, and is commonly used as a metric of IAQ. Indoor CO₂ concentrations can be significantly higher than outdoors due to human metabolism and activities. Even in presence of ventilation, controlling the CO₂ concentration below the Indoor Air Guideline Values (IAGVs) is a challenge, and many indoor environments including schools, offices and transportation exceed the recommended value of 1000 ppm_v. This is often accompanied by high concentration of other pollutants, including bio-effluents such as viruses, and the importance of mitigating the transmission of airborne diseases has been highlighted by the COVID-19 pandemic. On the other hand, the relatively high CO₂ concentration of indoor environments presents a thermodynamic advantage for direct air capture (DAC) in comparison to atmospheric CO₂ concentration. This review aims to describe the issues associated with poor IAQ, and to demonstrate the potential of indoor CO₂ DAC to purify indoor air while generating a renewable carbon stream that can replace conventional carbon sources as a building block for chemical production, contributing to the circular economy.

Upcoming Transformations in Integrated Energy/Chemicals Sectors: Some Challenges and Several Opportunities

The sociopolitical events over the past few years led to transformative changes in both the energy and chemical sectors. One of the most evident consequences of these events is the significant focus on sustainability. In fact, rather than an engaging discussion within elite social circles, the search for sustainability is now one of the hard requirements investors impose on companies. The concept of sustainability itself has developed since its inception, and now it encompasses environmental as well as socioeconomic aspects. The major players in the energy and chemical sectors seem to embrace these changes and the related challenges; in most cases, tangible ambitious goals have been proposed. For example, bp aims "to become a net zero company by 2050 or sooner, and to help the world get to net zero". Although tragic events such as the war in Ukraine directly affect global supply chains, leading to some reconsiderations in medium-term industrial and political strategies, trends and public demands seem determined to pursue ambitious sustainable goals, as tangible as the European Union's "Fit for 55" climate package, approved on May 12, 2022, which effectively bans internal combustion engines for new passenger cars and light commercial vehicles from 2035. These trends will likely lead to profound changes in both the chemical and energy sectors. While some predictions may miss the target, speculating about upcoming challenges and opportunities could help us prepare for the future. This is the purpose of this brief Perspective.

Weather-Climate Anomalies and Regional Transport Contribute to Air Pollution in Northern China During the COVID-19 Lockdown

Two persistent and heavy haze episodes during the COVID-19 lockdown (from 20 Jan to 22 Feb 2020) still occur in northern China, when anthropogenic emissions, particularly from transportation sources, are greatly reduced. To investigate the underlying cause, this study comprehensively uses in-situ measurements for ambient surface pollutants, reanalysis meteorological data and the WRF-Chem model to calculate the contribution of NOx emission change and weather-climate change to the "unexpectedly heavy" haze. Results show that a substantial NOx reduction has slightly decreased PM2.5 concentration. By contrast, the weakest East Asian winter monsoon (EAWM) in the 2019-2020 winter relative to the past decade is particularly important for haze occurrence. A warmer and moister climate is also favorable. Model results suggest that climate anomalies lead to a 25-50 μg m-3 increase of PM2.5 concentration, and atmospheric transport is also an important contributor to two haze episodes. The first haze is closely related to the atmospheric transport of pollutants from NEC to the south, and fireworks emissions in NEC are a possible amplifying factor that warrants future studies. The second one is caused by the convergence of a southerly wind and a mountain wind, resulting in an intra-regional transport within BTH, with a maximal PM2.5 increment of 50-100 μg m-3. These results suggest that climate change and regional transport are of great importance to haze occurrence in China, even with significant emission reductions of pollutants.

Examining the Human Activity-Intensity Change at Different Stages of the COVID-19 Pandemic across Chinese Working, Residential and Entertainment Areas

The COVID-19 pandemic has already resulted in more than 6 million deaths worldwide as of December 2022. The COVID-19 has also been greatly affecting the activity of the human population in China and the world. It remains unclear how the human activity-intensity changes have been affected by the COVID-19 spread in China at its different stages along with the lockdown and relaxation policies. We used four days of Location-based services data from Tencent across China to capture the real-time changes in human activity intensity in three stages of COVID-19-namely, during the lockdown, at the first stage of work resuming and at the stage of total work resuming-and observed the changes in different land use categories. We applied the mean decrease Gini (MDG) approach in random forest to examine how these changes are influenced by land attributes, relying on the CART algorithm in Python. This approach was also compared with Geographically Weighted Regression (GWR). Our analysis revealed that the human activity intensity decreased by 22-35%, 9-16% and 6-15%, respectively, in relation to the normal conditions before the spread of COVID-19 during the three periods. The human activity intensity associated with commercial sites, sports facilities/gyms and tourism experienced the relatively largest contraction during the lockdown. During the relaxations of restrictions, government institutions showed a 13.89% rise in intensity at the first stage of work resuming, which was the highest rate among all the working sectors. Furthermore, the GDP and road junction density were more influenced by the change in human activity intensity for all land use categories. The bus stop density was importantly associated with mixed-use land recovery during the relaxing stages, while the coefficient of density of population in entertainment land were relatively higher at these two stages. This study aims to provide additional support to investigate the human activity changes due to the spread of COVID-19 at different stages across different sectors.

Changes in Air Quality during the Period of COVID-19 in China

This paper revisits the heterogeneous impacts of COVID-19 on air quality. For different types of Chinese cities, we analyzed the different degrees of improvement in the concentrations of six air pollutants (PM2.5, PM10, SO2, NO2, CO, and O3) during COVID-19 by analyzing the predictivity of air quality. Specifically, we divided the sample into three groups: cities with severe outbreaks, cities with a few confirmed cases, and cities with secondary outbreaks. Ensemble empirical mode decomposition (EEMD), recursive plots (RPs), and recursive quantitative analysis (RQA) were used to analyze these heterogeneous impacts and the predictivity of air quality. The empirical results indicated the following: (1) COVID-19 did not necessarily improve air quality due to factors such as the rebound effect of consumption, and its impacts on air quality were short-lived. After the initial outbreak, NO2, CO, and PM2.5 emissions declined for the first 1-3 months. (2) For the cities with severe epidemics, air quality was improved, but for the cities with second outbreaks, air quality was first enhanced and then deteriorated. For the cities with few confirmed cases, air quality first deteriorated and then improved. (3) COVID-19 changed the stability of the air quality sequence. The predictability of the air quality index (AQI) declined in cities with serious epidemic situations and secondary outbreaks, but for the cities with a few confirmed cases, the AQI achieved a stable state sooner. The conclusions may facilitate the analysis of differences in air quality evolution characteristics and fluctuations before and after outbreaks from a quantitative perspective.

Wetland emission and atmospheric sink changes explain methane growth in 2020

Atmospheric methane growth reached an exceptionally high rate of 15.1 ± 0.4 parts per billion per year in 2020 despite a probable decrease in anthropogenic methane emissions during COVID-19 lockdowns¹. Here we quantify changes in methane sources and in its atmospheric sink in 2020 compared with 2019. We find that, globally, total anthropogenic emissions decreased by 1.2 ± 0.1 teragrams of methane per year (Tg CH₄ yr^-1), fire emissions decreased by 6.5 ± 0.1 Tg CH₄ yr^-1 and wetland emissions increased by 6.0 ± 2.3 Tg CH₄ yr^-1. Tropospheric OH concentration decreased by 1.6 ± 0.2 per cent relative to 2019, mainly as a result of lower anthropogenic nitrogen oxide (NO_x) emissions and associated lower free tropospheric ozone during pandemic lockdowns². From atmospheric inversions, we also infer that global net emissions increased by 6.9 ± 2.1 Tg CH₄ yr^-1 in 2020 relative to 2019, and global methane removal from reaction with OH decreased by 7.5 ± 0.8 Tg CH₄ yr^-1. Therefore, we attribute the methane growth rate anomaly in 2020 relative to 2019 to lower OH sink (53 ± 10 per cent) and higher natural emissions (47 ± 16 per cent), mostly from wetlands. In line with previous findings^3,4, our results imply that wetland methane emissions are sensitive to a warmer and wetter climate and could act as a positive feedback mechanism in the future. Our study also suggests that nitrogen oxide emission trends need to be taken into account when implementing the global anthropogenic methane emissions reduction pledge⁵.

Threats of COVID-19 arouse public awareness of climate change risks

Public climate change awareness is indispensable to dealing with climate change threats. Understanding whether and how the COVID-19 pandemic impacts on individuals’ climate change risk perception would thus be critical to green economic recovery. We conducted a longitudinal survey study in China when the pandemic was at its height and when it was mitigated. The cross-lagged analysis confirmed our assumed “arousal” effect of perceived COVID-19 risks on climate change risk awareness. We further tested and verified the proposed “dual-pathway” mechanisms of affective generalization (i.e., negative affective states aroused by COVID-19 “spillover” to the assessment of climate change risk) and cognitive association (i.e., the outbreak of COVID-19 awakens people’s recognition of the human-nature-climate issues) via multiple mediation analyses. Our results implied that climate policies could be integrated into pandemic control, and that the public should be more awakened to confront multiple crises with proper guidance.

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Public COVID-19 risk perception arouses their climate change awareness

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A longitudinal survey in China was conducted to verify this arousal effect

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Generalized negative affect states explain the effect

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Cognitive association also explains the effect

From low carbon to carbon neutrality: A bibliometric analysis of the status, evolution and development trend

With global climate change becoming increasingly serious, carbon neutrality, a key strategy to mitigate climate change, has attracted widespread attention. However, due to the multidisciplinary and complexity of carbon neutrality studies, as well as the diversification of research content, a comprehensive review and systematic synthesis of which is quite limited. In this paper, a bibliometric analysis on the topic of carbon neutrality is conducted to reveal the research progress from a quantitative and visual perspective and describe the evolution of research hotspots. The results show that carbon neutrality research is abundant at both the macro and micro levels. Low carbon development is the premise of carbon neutrality, and emission reduction and carbon sinks are the basis of carbon neutrality. The degree of research varies significantly in different countries, with China dominating in the number of publications, followed by the USA and the UK. The realization of carbon neutrality cannot be fully achieved by one single perspective and requires a comprehensive and systematic analysis of technology, economy, and society. Carbon neutrality is a technology-driven process guided by policy. Economically, carbon taxes and carbon markets are two important market mechanisms for reducing carbon emissions. Technically, researches of negative carbon technologies and renewable energy are growing rapidly. Carbon market, carbon negative technology, circular economy, and green energy will become the focus of future research. This paper helps scholars to understand the overall state of carbon neutrality research and provides a historical reference for future research.

Climate Change Drives the Transmission and Spread of Vector-Borne Diseases: An Ecological Perspective

Climate change affects ecosystems and human health in multiple dimensions. With the acceleration of climate change, climate-sensitive vector-borne diseases (VBDs) pose an increasing threat to public health. This paper summaries 10 publications on the impacts of climate change on ecosystems and human health; then it synthesizes the other existing literature to more broadly explain how climate change drives the transmission and spread of VBDs through an ecological perspective. We highlight the multi-dimensional nature of climate change, its interaction with other factors, and the impact of the COVID-19 pandemic on transmission and spread of VBDs, specifically including: (1) the generally nonlinear relationship of local climate (temperature, precipitation and wind) and VBD transmission, with temperature especially exhibiting an n-shape relation; (2) the time-lagged effect of regional climate phenomena (the El Niño-Southern Oscillation and North Atlantic Oscillation) on VBD transmission; (3) the u-shaped effect of extreme climate (heat waves, cold waves, floods, and droughts) on VBD spread; (4) how interactions between non-climatic (land use and human mobility) and climatic factors increase VBD transmission and spread; and (5) that the impact of the COVID-19 pandemic on climate change is debatable, and its impact on VBDs remains uncertain. By exploring the influence of climate change and non-climatic factors on VBD transmission and spread, this paper provides scientific understanding and guidance for their effective prevention and control.

Effect of restricted emissions during COVID-19 on atmospheric aerosol chemistry in a Greater Cairo suburb: Characterization and enhancement of secondary inorganic aerosol production

To prevent the rapid spreading of the COVID-19 pandemic, the Egyptian government had imposed partial lockdown restrictions which led emissions reduction. This served as ideal conditions for a natural experiment, for study the effect of partial lockdown on the atmospheric aerosol chemistry and the enhanced secondary inorganic aerosol production in a semi-desert climate area like Egypt. To achieve this objective, SO₂, NO₂, and PM_2.5 and their chemical compositions were measured during the pre-COVID, COVID partial lockdown, and post-COVID periods in 2020 in a suburb of Greater Cairo, Egypt. Our results show that the SO₂, NO₂, PM_2.5 and anthropogenic elements concentrations follow the pattern pre-COVID > post-COVID > COVID partial lockdown. SO₂ and NO₂ reductions were high compared with their secondary products during the COVID partial lockdown compared with pre-COVID. Although, PM_2.5, anthropogenic elements, NO₂, SO₂, SO₄ ^2-, NO₃ ^-, and NH₄ ⁺ decreased by 39%, 38-55%, 38%, 32.9%. 9%, 14%, and 4.3%, respectively, during the COVID partial lockdown compared with pre-COVID, with the secondary inorganic ions (SO₄ ^2-, NO₃ ^-, and NH₄ ⁺) being the dominant components in PM_2.5 during the COVID partial lockdown. Moreover, the enhancement of NO₃ ^- and SO₄ ^2- formation during the COVID partial lockdown was high compared with pre-COVID. SO₄ ^2- and NO₃ ^- formation enhancements were significantly positive correlated with PM_2.5 concentration. Chemical forms of SO₄ ^2- and NO₃ ^- were identified in PM_2.5 based on their NH₄ ⁺/SO₄ ^2- molar ratio and correlation between NH₄ ⁺ and both NO₃ ^- and SO₄ ^2-. The particles during the COVID partial lockdown were more acidic than those in pre-COVID.

Climate change and COVID-19: Interdisciplinary perspectives from two global crises

The repercussions of the COVID-19 pandemic and climate change - two major current global crises - are far-reaching, the parallels between the two are striking, and their influence on one another are significant. Based on the wealth of evidence that has emerged from the scientific literature during the first two years of the pandemic, this study argues that these two global crises require holistic multisectoral mitigation strategies. Despite being different in nature, neither crisis can be effectively mitigated without considering their interdependencies. Herein, significant interactions between these two crises are highlighted and discussed. Major implications related to the economy, energy, technology, environment, food systems and agriculture sector, health systems, policy, management, and communities are detailed via a review of existing joint literature. Based on these outcomes, practical recommendations for future research and management are provided. While the joint timing of these crises has created a global conundrum, the COVID-19 pandemic has demonstrated opportunities and lessons for devising sustainable recovery plans in relation to the climate crisis. The findings indicated that governments should work collaboratively to develop durable and adjustable strategies in line with long-term, global decarbonisation targets, promote renewable energy resources, integrate climate change into environmental policies, prioritise climate-smart agriculture and local food systems, and ensure public and ecosystem health. Further, differences in geographic distributions of climate change and COVID-19 related death cases revealed that these crises pose different threats to different parts of the world. These learnings provide insights to address the climate emergency - and potential future global problems with similar characteristics - if international countries act urgently and collectively.

Has the COVID-19 pandemic strengthened confidence in managing the climate crisis? Transfer of efficacy beliefs after experiencing lockdowns in Switzerland and Austria

In the spring of 2020, countries introduced lockdowns as radical measures to deal with the first wave of the COVID-19 pandemic, which led to strong disruptions of people's everyday lives. Such drastic collective measures had previously seemed inconceivable in relation to other urgent crises, such as the climate crisis. In this paper, we ask how individual, participatory, and collective efficacy beliefs in dealing with the COVID-19 pandemic transferred to efficacy beliefs regarding the climate crisis. We present comparative results from two surveys: Study 1 assesses efficacy beliefs among German-speaking Swiss residents (n = 1,016), shortly after lockdown measures were relaxed. Study 2 compares changes in efficacy beliefs among Austrian high school students (n = 113) before and after the lockdown. In Study 1, climate-related self- and participatory efficacy are enhanced by the corresponding COVID-19-related beliefs. Climate-related efficacy beliefs mediate the effect of COVID-related counterparts on climate-friendly behavior and policy support. Study 2 shows that COVID-19-related efficacy beliefs are transferred to climate-related counterparts over time, and that the transfer of participatory efficacy is moderated by perceived similarity of the two crises. Experiencing successful individual and collective action during the COVID-19 pandemic seems to inspire confidence in dealing with climate change. Underlying processes (direct transfer, consistency, awareness-raising, learning) are discussed.

Cumulative effects of air pollution and climate drivers on COVID-19 multiwaves in Bucharest, Romania

Over more than two years of global health crisis due to ongoing COVID-19 pandemic, Romania experienced a five-wave pattern. This study aims to assess the potential impact of environmental drivers on COVID-19 transmission in Bucharest, capital of Romania during the analyzed epidemic period. Through descriptive statistics and cross-correlation tests applied to time series of daily observational and geospatial data of major outdoor inhalable particulate matter with aerodynamic diameter ≤ 2.5 µm (PM2.5) or ≤ 10 µm (PM10), nitrogen dioxide (NO₂), ozone (O₃), sulfur dioxide (SO₂), carbon monoxide (CO), Aerosol Optical Depth at 550 nm (AOD) and radon (²²²Rn), we investigated the COVID-19 waves patterns under different meteorological conditions. This study examined the contribution of individual climate variables on the ground level air pollutants concentrations and COVID-19 disease severity. As compared to the long-term average AOD over Bucharest from 2015 to 2019, for the same year periods, this study revealed major AOD level reduction by ~28 % during the spring lockdown of the first COVID-19 wave (15 March 2020-15 May 2020), and ~16 % during the third COVID-19 wave (1 February 2021-1 June 2021). This study found positive correlations between exposure to air pollutants PM2.5, PM10, NO₂, SO₂, CO and ²²²Rn, and significant negative correlations, especially for spring-summer periods between ground O₃ levels, air temperature, Planetary Boundary Layer height, and surface solar irradiance with COVID-19 incidence and deaths. For the analyzed time period 1 January 2020-1 April 2022, before and during each COVID-19 wave were recorded stagnant synoptic anticyclonic conditions favorable for SARS-CoV-2 virus spreading, with positive Omega surface charts composite average (Pa/s) at 850 mb during fall- winter seasons, clearly evidenced for the second, the fourth and the fifth waves. These findings are relevant for viral infections controls and health safety strategies design in highly polluted urban environments.

Urban air quality in Xinjiang and snow chemistry of Urumqi Glacier No. 1 during COVID-19's restrictions

The unprecedented COVID-19 outbreak impacted the world in many aspects. Air pollutants were largely reduced in cities worldwide in 2020. Using samples from two snow pits dug separately in 2019 and 2020 in Urumqi Glacier No. 1 (UG1) in the Xinjiang Uygur Autonomous Region (Xinjiang), China, we measured water-stable isotopes, soluble ions, and black and organic carbon (BC and OC). Both carbon types show no significant variations in the snow-pit profiles dated from 2018 through 2020. The deposition of anthropogenically induced soluble ions (K⁺, Cl^-, SO₄^2-, and NO₃^-) in the snow decreased to 20-40% of their respective concentrations between 2019 and 2020; however, they increased 2- to fourfold from 2018 to 2019. We studied the daily concentrations of SO₂ (2019-2020), NO₂ (2015-2020), CO (2019-2020), and PM_2.5 (2019-2020) measured in the sixteen major cities and towns across Xinjiang. The variabilities in these air pollutants were supposed to illustrate the air quality in the urban area and represent the change in the source area. The NO₂ decreased in response to mobility restrictions imposed by local governments, while SO₂, CO, and PM_2.5 did not consistently correspond. This difference indicates that the restriction measures primarily affected traffic. The increases in chemical species in the snow from 2018 to 2019 and the subsequent decreases from 2019 to 2020 were consistent with the variations in SO₂ and NO₂ measured in urban air and estimated by MERRA-2 model. Therefore, the pandemic could possibly have an impact on snow chemistry of the Tien-Shan glaciers via reduced traffic and industrial intensity; more evidence would be obtained from ice cores, tree rings, and other archives in the future.