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An alarming finding for biodiversity is that global warming and pesticides often interact synergistically. Yet, this synergism may not capture the full picture because two counteracting processes may reduce the higher impact of pesticides under warming: higher pesticide degradation in the environment and thermal adaptation of populations., We tested for the effects of warming and multiple pulses of the insecticide chlorpyrifos on life history and fitness-related physiological traits in the damselfly Ischnura elegans. To assess whether thermal adaptation is able to mitigate the impact of the pesticide under future warming, we exposed replicated populations from a colder, high latitude and from a warmer, low latitude in a common garden rearing experiment at 20 and 24 °C (the respective mean summer water temperatures at both latitudes)., At the higher temperature pesticide degradation was higher, leading to less accumulation after multiple pulses compared to the lower temperature. Accordingly, the pesticide caused less mortality and less oxidative damage at the higher temperature. This contradicts the general belief (based on studies that kept pesticide concentrations constant) of a higher impact of pesticides under warming. Furthermore, the reduction of the impact of the pesticide at the higher temperature was more pronounced in the warm-adapted low-latitude populations, indicating a counteracting role of thermal adaptation., Policy implications. Our findings provide proof-of-principle for two key insights that will allow improving ecological risk assessment of pesticides under global warming: (i) higher pesticide degradation in the environment under warming may temper the impact of multiple pesticide pulses; (ii) gradual thermal evolution may further reduce the impact of pesticides at high latitudes under global warming. This knowledge can be very important for policy makers to arrive at a more realistic forecasting of the impacts of chemical pollution and climate change interactions on organisms. [ABSTRACT FROM AUTHOR]

Agriculture's global environmental impacts are widely expected to continue expanding, driven by population and economic growth and dietary changes. This Review highlights climate change as an additional amplifier of agriculture's environmental impacts, by reducing agricultural productivity, reducing the efficacy of agrochemicals, increasing soil erosion, accelerating the growth and expanding the range of crop diseases and pests, and increasing land clearing. We identify multiple pathways through which climate change intensifies agricultural greenhouse gas emissions, creating a potentially powerful climate change-reinforcing feedback loop. The challenges raised by climate change underscore the urgent need to transition to sustainable, climate-resilient agricultural systems. This requires investments that both accelerate adoption of proven solutions that provide multiple benefits, and that discover and scale new beneficial processes and food products.

An understanding of the combined effects of climate change (CC) and other anthropogenic stressors, such as chemical exposures, is essential for improving ecological risk assessments of vulnerable ecosystems. In the Great Barrier Reef, coral reefs are under increasingly severe duress from increasing ocean temperatures, acidification, and cyclone intensities associated with CC. In addition to these stressors, inshore reef systems, such as the Mackay-Whitsunday coastal zone, are being impacted by other anthropogenic stressors, including chemical, nutrient, and sediment exposures related to more intense rainfall events that increase the catchment runoff of contaminated waters. To illustrate an approach for incorporating CC into ecological risk assessment frameworks, we developed an adverse outcome pathway network to conceptually delineate the effects of climate variables and photosystem II herbicide (diuron) exposures on scleractinian corals. This informed the development of a Bayesian network (BN) to quantitatively compare the effects of historical (1975-2005) and future projected climate on inshore hard coral bleaching, mortality, and cover. This BN demonstrated how risk may be predicted for multiple physical and biological stressors, including temperature, ocean acidification, cyclones, sediments, macroalgae competition, and crown of thorns starfish predation, as well as chemical stressors such as nitrogen and herbicides. Climate scenarios included an ensemble of 16 downscaled models encompassing current and future conditions based on multiple emission scenarios for two 30-year periods. It was found that both climate-related and catchment-related stressors pose a risk to these inshore reef systems, with projected increases in coral bleaching and coral mortality under all future climate scenarios. This modeling exercise can support the identification of risk drivers for the prioritization of management interventions to build future resilient reefs. Integr Environ Assess Manag 2024;20:401-418. © 2023 Norwegian Institute for Water Research and The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA., (© 2023 Norwegian Institute for Water Research and The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)