Trade scenarios compensating for halted wheat and maize exports from Russia and Ukraine increase carbon emissions without easing food insecurity

Decline in carbon emission intensity of global agriculture has stagnated recently

Using global data for around 180 countries and territories and 170 food/feed types primarily derived from FAOSTAT, we have systematically analyzed the changes in greenhouse gas (GHG) emission intensity (GHGi) (kg CO2eq per kg protein production) over the past six decades. We found that, with large spatial heterogeneity, emission intensity decreased by nearly two-thirds from 1961 to 2019, predominantly in the earlier years due to agronomic improvement in productivity. However, in the most recent decade, emission intensity has become stagnant, and in a few countries even showed an increase, due to the rapid increase in livestock production and land use changes. The trade of final produced protein between countries has potentially reduced the global GHGi, especially for countries that are net importers with high GHGi, such as many in Africa and South Asia. Overall, a continuous decline of emission intensity in the future relies on countries with higher emission intensity to increase agricultural productivity and minimize land use changes. Countries with lower emission intensity should reduce livestock production and increase the free trade of agricultural products and improve the trade optimality.

Regional irrigation expansion can support climate-resilient crop production in post-invasion Ukraine

Ukraine supplies a large proportion of grain and oilseeds to the world market and faces disruptions from the Russian invasion in 2022. Here we explore the combined effects of the invasion and climate change on Ukraine's irrigation. In 2021, only 1.6% of Ukraine's cropland was irrigated. Of this portion, 73% experienced substantial declines in irrigated crop production following the invasion. We estimate that by the mid-twenty-first century, three-quarters of croplands will experience water shortages, making business-as-usual rain-fed agricultural practices inadequate in addressing the challenges posed by climate change. We explore how leveraging local surface and groundwater resources could enable sustainable irrigation expansion over 18 million hectares of croplands and form a viable climate adaptation strategy. Finally, we identify regions for implementing enhancements or expansions of irrigation systems that can foster a more resilient agricultural sector-underscoring the growing importance of irrigation in sustaining crop production in Ukraine.

Strategies for Enhancing Plant Immunity and Resilience Using Nanomaterials for Sustainable Agriculture

Research on plant-nanomaterial interactions has greatly advanced over the past decade. One particularly fascinating discovery encompasses the immunomodulatory effects in plants. Due to the low doses needed and the comparatively low toxicity of many nanomaterials, nanoenabled immunomodulation is environmentally and economically promising for agriculture. It may reduce environmental costs associated with excessive use of chemical pesticides and fertilizers, which can lead to soil and water pollution. Furthermore, nanoenabled strategies can enhance plant resilience against various biotic and abiotic stresses, contributing to the sustainability of agricultural ecosystems and the reduction of crop losses due to environmental factors. While nanoparticle immunomodulatory effects are relatively well-known in animals, they are still to be understood in plants. Here, we provide our perspective on the general components of the plant's immune system, including the signaling pathways, networks, and molecules of relevance for plant nanomodulation. We discuss the recent scientific progress in nanoenabled immunomodulation and nanopriming and lay out key avenues to use plant immunomodulation for agriculture. Reactive oxygen species (ROS), the mitogen-activated protein kinase (MAPK) cascade, and the calcium-dependent protein kinase (CDPK or CPK) pathway are of particular interest due to their interconnected function and significance in the response to biotic and abiotic stress. Additionally, we underscore that understanding the plant hormone salicylic acid is vital for nanoenabled applications to induce systemic acquired resistance. It is suggested that a multidisciplinary approach, incorporating environmental impact assessments and focusing on scalability, can expedite the realization of enhanced crop yields through nanotechnology while fostering a healthier environment.

Challenges to environmental governance arising from the Russo-Ukrainian conflict: Evidence from carbon emissions

The destruction of ecosystems, increase in carbon emissions, and volatility of energy prices following the outbreak of the Russo-Ukrainian conflict constitute a complex situation that environmental managers must cope with. In response, this study aims to explore the impact of the Russo-Ukrainian conflict on carbon emissions in the European Union (EU) and associated heterogeneity factors. This study utilized stacked data from 2021 to 2022 on daily carbon emissions and used the differences-in-differences (DID) model as its methodological framework. This study also provides additional analyses for the United States (US), the United Kingdom (UK), and Russia. The full-blown Russo-Ukrainian conflict led to a significant increase in carbon emissions in the EU, averaging 0.092 MtCO2. Further investigations showed that the conflict led to a significant increase in energy prices and that changes in the prices of different energy sources had a heterogeneous effect on carbon emissions. Specifically, an increase in natural gas prices drove a rise in carbon emissions, whereas an increase in oil prices led to a decrease in carbon emissions in the EU. Third, the conflict also affected countries outside the EU, including the US and the UK, which experienced significant increases in carbon emissions in contrast to Russia, which underwent a decline. Finally, the study identified four sectors - international aviation, industry, power, and residential - as the primary contributors to elevated carbon emissions in the EU. This study provides a novel perspective for exploring the interplay between conflicts and carbon emissions and offers valuable insights into shaping effective environmental management policies and measures.

Access to global wheat reserves determines country-level vulnerability to conflict-induced Ukrainian wheat supply disruption

The Russia-Ukraine conflict reduced global wheat supplies, yet the food security implications vary across countries. We identify a 39% decrease in Ukrainian wheat exports in 2022 resulting in >70% import losses in some of the countries most vulnerable to these disruptions, with substantial impacts felt in Egypt, Oman, Saudi Arabia, Libya, Mauritania, Yemen and Lebanon. Differential impacts are a function of access to capital and international trade, suggesting the need for policy measures to defuse the impending food crisis.

Abrupt exacerbation in air quality over Europe after the outbreak of Russia-Ukraine war

Much attention has been paid to the world economy and social situations in response to the outbreak of war between Russia and Ukraine in the context of COVID-19. However, much less attention has been paid to the detrimental effect of war on the atmospheric environment. Here, we used an extended deweathered-detrended technique to quantitatively evaluate changes in ambient NO2, O3, and PM2.5 AQI levels arising from emission changes (due to pandemic-driven lockdowns and war-related activities) in European cities. Results show pandemic-induced lockdowns mitigated regional air pollution in Europe, but the war activities led to an average increase of approximately 9.78% in PM2.5 and 10.07% in NO2, along with an average decrease of about 7.93% in O3 levels in cities near the war zones. Moreover, the regional air pollution exacerbated by the war activities has offset the improvements in air quality observed during the COVID-19 pandemic. The potential mechanism analysis show that the increase in atmospheric pollutant emissions driven by the war activities led to the complexity of chemical reactions in the mixed atmospheric system, which posed a huge challenge to the alleviation of air pollution in the region. This study highlights the urgent need for a ceasefire from an environmental perspective.

Predicting the Potential Impact of Emergency on Global Grain Security: A Case of the Russia-Ukraine Conflict

Global emergencies have a profound impact on exacerbating food insecurity, and the protracted Russia-Ukraine conflict has emerged as a significant driver of a global food crisis. Accurately quantifying the impact of this conflict is crucial for achieving sustainable development goals. The multi-indicator comprehensive evaluation approach was used to construct a grain security composite index (GSCI). Moreover, econometric model was used to predict the potential impacts of the conflict on global grain security in 2030 under two scenarios: with and without the "Russia-Ukraine conflict". The results conclude that global food prices reached unprecedented levels as a consequence of the conflict, leading to notable fluctuations in food prices, especially with a significant surge in wheat prices. The conflict had a negative impact on global grain security, resulting in a decline in grain security from 0.538 to 0.419. Predictions indicate that the influence of the conflict on global grain security will be substantially greater compared to the scenario without the conflict in 2023-2030, ranging from 0.033 to 0.13. Furthermore, grain security will first decrease and then increase under the sustained consequences of the conflict. The achievement of the 2030 sustainable development goals will encounter significant challenges in light of these circumstances.

Exploring public attention and sentiment toward carbon neutrality: evidence from Chinese social media Sina Weibo

Introduction

Exploring the public's cognition toward carbon neutrality is conducive to improving the quality and effectiveness of policymaking, and promoting the realization of carbon neutrality goals. This study aims to explore the public's attention and sentiment toward carbon neutrality from the perspective of social psychology.

Methods

Using posts on carbon neutrality from the Chinese social media platform Sina Weibo as the data source, this study uses statistical analysis, the Mann-Kendall method, keyword analysis, the BERT model, and the LDA model to explore public attention and sentiment.

Results

The results show that: (1) men, people living east of the Hu line (economically developed regions), and the public in the energy finance market are more concerned about carbon neutrality; (2) high public attention and great dynamic changes in public attention toward carbon neutrality could be trigged by highly credible government or international governmental organizations' information; (3) public sentiment toward carbon neutrality is mostly positive; however, specific topics affect public sentiment differently.

Discussion

The research results contribute to policymakers' better understanding of the trend of public attention and sentiment toward carbon neutrality, and support improvements in the quality and impact of policymaking.

The Russia-Ukraine war disproportionately threatens the nutrition security of developing countries

While the ongoing Russia-Ukraine war threatens global nutrition security, the magnitude and extent of its impact remain underexamined. Here we show that, with the lowest level of war duration, severity, sanction, and countries involved, the direct and indirect impacts of the war and sanctions could newly place 67.3 million people (roughly equals the total population of France) in undernourishment and 316.7 million people (roughly equals the total population of Bangladesh and Russia) suffering from extreme national food insecurity. Approximately 95% of the affected population are from developing countries, highlighting the vulnerability of food supply in these countries. Both the undernourished population and its inequality across countries will substantially grow, if war duration and severity increase. If the war is prolonged to early 2024, future agricultural growth cannot fully offset the negative impacts, and global hunger will still very likely exacerbate. We conclude that targeted measures should be placed in developing countries and their vulnerable populations to reconstruct a just, healthy, and environmentally sustainable food system.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43621-022-00112-8.