With climate change, the COVID-19 pandemic, and ongoing conflicts, food systems and the diets they produce are facing increasing fragility. In a turbulent, hot world, threatened resiliency and sustainability of food systems could make it all the more complicated to nourish a population of 9.7 billion by 2050. Climate change is having adverse impacts across food systems with more frequent and intense extreme events that will challenge food production, storage, and transport, potentially imperiling the global population's ability to access and afford healthy diets. Inadequate diets will contribute further to detrimental human and planetary health impacts. At the same time, the way food is grown, processed, packaged, and transported is having adverse impacts on the environment and finite natural resources further accelerating climate change, tropical deforestation, and biodiversity loss. This state-of-the-science iterative review covers three areas. The paper's first section presents how climate change is connected to food systems and how dietary trends and foods consumed worldwide impact human health, climate change, and environmental degradation. The second area articulates how food systems affect global dietary trends and the macro forces shaping food systems and diets. The last section highlights how specific food policies and actions related to dietary transitions can contribute to climate adaptation and mitigation responses and, at the same time, improve human and planetary health. While there is significant urgency in acting, it is also critical to move beyond the political inertia and bridge the separatism of food systems and climate change agendas that currently exists among governments and private sector actors. The window is closing and closing fast.

This study assesses the effect of lockdown, due to the coronavirus disease (COVID-19) pandemic, on the concentration of different air pollutants and overall air quality of a less industrialized region (Kerala) of India. We analysed data from four ambient air quality stations over three years (January to May, 2018-2020) with pairwise comparisons, trend analysis, etc. Results indicated unprecedented reduction in the concentration of the air pollutants: nitrogen dioxide, NO (-48 %), oxides of nitrogen, NO (-53 % to -90 %), carbon monoxide, CO (-24 % to -67 %) and the particulate matter (-24 % to -47 % for particulate matter with a diameter of less than 2.5 μm, PM; -17 % to -20 % for particulate matter with a diameter of less than 10 μm, PM), as well as the reduction of the National Air Quality Index (NAQI). These reductions indicate an overall improvement of the ambient air quality due to restrictions on transportation, construction, and the industrial sectors during lockdown, even in an area considered less industrial. Despite the general decreasing trend of the concentration of various air pollutants from January to May, suggesting seasonal influences, the trend was intensified in the year 2020 due to the added effect of the lockdown measures. Comparison of the results with those from larger and more industrialized cities suggests that the effects of lockdown are more variable, and focused on the levels of gaseous pollutants. Findings from this study demonstrate the far-reaching effects and implications of the COVID-19 lockdown on ambient air quality, even on less industrialized and less urbanized regions.

Pandemics have accelerated in frequency in recent decades, with COVID-19 the latest to join the list. Emerging in late 2019 in Wuhan, China, the virus has spread quickly through the world, affecting billions of people through quarantine, and at the same time claiming more than 800,000 lives worldwide. While early reflections from the academic community have tended to target the microbiology, medicine, and animal science communities, this article articulates a viewpoint from a perspective of human interactions with Earth systems. We highlight the link between rising pandemics and accelerating global human impacts on Earth, thereby suggesting that pandemics may be an emerging element of the "Anthropocene." Examples from Denver, Colorado, USA, show how policy responses to the COVID-19 pandemic changed human-environment interactions and created anomalous landscapes at the local scale, in relation to the quality of air and patterns of acquiring and consuming food. In recognizing the significance of novel infectious diseases as part of understanding human-landscape interactions in the Anthropocene, as well as the multi-scale interconnectedness between environment and health, this viewpoint converges toward an urgent need for new paradigms for research and teaching. The program required extends well beyond the already broad interdisciplinary scholarship essential for addressing human-landscape interactions, by integrating the work of health scientists, disease specialists, immunologists, virologists, veterinarians, behavioral scientists, and health policy experts.

This study provides estimates of climate change impacts on U.S. agricultural yields and the agricultural economy through the end of the 21st century, utilizing multiple climate scenarios. Results from a process-based crop model project future increases in wheat, grassland, and soybean yield due to climate change and atmospheric CO change; corn and sorghum show more muted responses. Results using yields from econometric models show less positive results. Both the econometric and process-based models tend to show more positive yields by the end of the century than several other similar studies. Using the process-based model to provide future yield estimates to an integrated agricultural sector model, the welfare gain is roughly $16B/year (2019 USD) for domestic producers and $6.2B/year for international trade, but domestic consumers lose $10.6B/year, resulting in a total welfare gain of $11.7B/year. When yield projections for major crops are drawn instead from econometric models, total welfare losses of more than $28B/year arise. Simulations using the process-based model as input to the agricultural sector model show large future production increases for soybean, wheat, and sorghum and large price reductions for corn and wheat. The most important factors are those about economic growth, flooding, international trade, and the type of yield model used. Somewhat less, but not insignificant factors include adaptation, livestock productivity, and damages from surface ozone, waterlogging, and pests and diseases.