Background
This mini-lecture, explores the relationship between climate change and chemical pollution. Far from being independent issues, these two drivers of biodiversity loss interact in ways that significantly alter environmental risk profiles.
Climate Projections and Chemical Use
Using Representative Concentration Pathways (RCPs), the Met Office predicts that the UK will transition towards warmer temperatures, drier summers, and wetter winters by the end of the 21st century. These shifts directly influence drivers of chemical usage. For instance, increased solar radiation increases the use of UV-filters and pharmaceuticals (such as chemotherapy drugs and cortisone creams), while changing pest pressures in agriculture require new pesticide regimes. Furthermore, extreme weather events resulting in wildfires increase the environmental load of chemicals in firefighting foams.
Fate, Transport, and Environmental Exposure
Climate change modifies the environmental exposure of chemicals by influencing degradation, deposition, transport and transformation process. Rising temperatures can accelerate biodegradation potentially reducing the persistence of some substances, whereas increased flooding and storm surges remobilise "legacy" chemicals trapped in sediments, redistributing pollutants across ecosystems.
Shifts in Biodiversity and Sensitivity
Climate change influences the abundance and distribution of species potentially exposed to environmental chemicals. Species composition determines the sensitivity of assemblages and chemical-specific variation in species sensitivity drives variation in the relative sensitivity of those assemblages. Under the high-emission RCP 8.5 scenario, 76% of UK freshwater assemblages are predicted to become more sensitive to chemical exposure due to climate-induced changes in species composition.
The CITS and TICS Framework
The interaction between temperature and toxicity is bidirectional:
• Climate-Induced Chemical Toxicant Sensitivity (CITS): Warming can change the toxicity of chemicals by affecting toxicokinetic processes.
• Toxicant-Induced Climate Change Sensitivity (TICS): Exposure to pollutants can lower an organism’s resilience to climate stressors.
Biodiversity loss, climate change and pollution
The three major environmental threats facing the planet – biodiversity loss, climate change and pollution – are interlinked. Climate-chemical interactions can result in biodiversity loss, which in turn can affect environmental exposure and ecological receptors, creating feedback loops that exacerbates environmental degradation. Addressing the “triple planetary crisis” requires a holistic risk assessment strategy that accounts for the complex interdependencies between a climate change, pollution and biodiversity loss.
Lorraine Maltby from the Unversity of Sheffield talks about the implications of climate change for the ecological risk of chemicals
Key Reading
Bolan S, Padhye LP, Jasemizad T, Govarthanan M, Karmegam N, Wijesekara H, Amarasiri D, Hou D, Zhou P, Biswal BK, Balasubramanian R, Wang H, Siddique KHM, Rinklebe J. Kirkham MB, Bolan N. (2024) Impacts of climate change on the fate of contaminants through extreme weather events. Science of The Total Environment 909: 168388. DOI 10.1016/j.scitotenv.2023.168388.
Cairns J, Heath AG, Parker BC. (1975) The effects of temperature upon the toxicity of chemicals to aquatic organisms. Hydrobiologia 47: 135–171. DOI: 10.1007/BF00036747
Delnat V, Tran TT, Verheyen J, Van Dinh K, Janssens L, Stoks R. (2019) Temperature variation magnifies chlorpyrifos toxicity differently between larval and adult mosquitoes. Science of The Total Environment 690: 1237-1244. DOI: 10.1016/j.scitotenv.2019.07.030.
Domisch S, Araújo MB, Bonada N, Pauls SU, Jähnig SC, Haase P. (2013) Modelling distribution in European stream macroinvertebrates under future climates. Global Change Biology. 19: 752-62. DOI: 10.1111/gcb.12107
Hader JD, Lane T, Boxall ABA, MacLeod M, Di Guardo A. (2022) Enabling forecasts of environmental exposure to chemicals in European agriculture under global change. Science of The Total Environment 840: 156478 DOI: 10.1016/j.scitotenv.2022.156478.
Harwood AD, You J, Lydy MJ. (2009) Temperature as a toxicity identification evaluation tool for pyrethroid insecticides: Toxicokinetic confirmation. Environmental Toxicology and Chemistry 28:1051–1058. DOI: 10.1897/08-291.1
Moe SJ, Brix KV, Landis WG, Stauber JL, Carriger JF, Hader JD, Kunimitsu T, Mentzel S, Nathan R, Noyes PD, Oldenkamp R, Rohr JR, van den Brink PJ, Verheyen J, Benestad RE (2023) Integrating climate model projections into environmental risk assessment: A probabilistic modeling approach. Integrated Environmental Assessment and Management 20: 367–383 DOI: 10.1002/ieam.4879
Noyes PD, Lema SC. (2015) Forecasting the impacts of chemical pollution and climate change interactions on the health of wildlife. Current Zoology 61: 669–689. DOI 10.1093/czoolo/61.4.669
Redshaw CH, Stahl-Timmins WM, Fleming LE, Davidson I, Depledge MH. (2013) Potential Changes in Disease Patterns and Pharmaceutical Use in Response to Climate Change. Journal of Toxicology and Environmental Health, Part B, 16: 285–320. DOI 10.1080/10937404.2013.802265
Sinclair T. Craig P, Maltby L. (2024) Climate warming shifts riverine macroinvertebrate communities to be more sensitive to chemical pollutants. Global Change Biology 30: e17254. DOI 10.1111/gcb.17254
Slooff W. (1983) Benthic macroinvertebrates and water quality assessment: Some toxicological considerations. Aquatic Toxicology 4: 73-82 DOI:10.1016/0166-445X(83)90062-0.
Other reading materials
Cains MG, Desrousseaux AOS, Boxall ABA, Molander S, Molina-Navarro E, Sussams J, Critto A, Stahl Jr. RG, Rother H-A. (2024) Environmental management cycles for chemicals and climate change, EMC4: A new conceptual framework contextualizing climate and chemical risk assessment and management. Integrated Environmental Assessment and Management 20: 433–453 DOI: 10.1002/ieam.4872
He W, Chen C, Yang L, Chen Z, Zhu L, Zhu L, Feng J (2025) Chemical Ecological Risk Assessment for Aquatic Life Under Climate Change: A Review from Occurrence, Bioaccumulation, and Toxicity Perspective. Reviews of Environmental Contamination and Toxicology 263: 10. DOI10.1007/s44169-025-00085-5
Hooper MJ, Ankley GT, Cristol DA, Maryoung LA, Noyes PD, Pinkerton KE. (2013) Interactions between chemical and climate stressors: A role for mechanistic toxicology in assessing climate change risks. Environmental Toxicology and Chemistry 32: 32–48. DOI: 10.1002/etc.2043