Climate Change and Emerging Food Safety Risks

Climate change refers to long-term shifts in weather patterns and average temperatures on Earth. These are mainly caused by human activities such as the burning of fossil fuels and deforestation. Our activities release greenhouse gases, such as carbon dioxide and others, into the atmosphere, trapping heat and leading to global warming. Climate change has far-reaching consequences, including a range of emerging food safety risks.

Impact on Food Safety and Food Security

One of the main impacts of climate change on food safety is the alteration of environmental conditions. It affects the growth, distribution, and survival of pathogens and pests. Rising temperatures, changing rainfall patterns, and extreme weather events create suitable conditions for the spread of foodborne illnesses.

The Intergovernmental Panel on Climate Change, the UN’s body in charge of assessing climate change’s evolution and impacts, published in 2022 the IPCC Sixth Assessment Report. This report provides extensive scientific evidence of the impacts of climate change on food safety. Climate change is enhancing existing challenges and creating new threats to food security and safety. 

In this latest report, the panel concluded that climate-related emerging food safety risks are increasing globally in agriculture and fisheries. Higher temperatures and humidity caused by climate change increases toxigenic fungi on many food crops. Harmful algal blooms and water-borne diseases threaten food security and the economy and livelihoods of many coastal communities. 

Increasing ocean warming and acidification are enhancing movement and bioaccumulation of toxins and contaminants into marine food webs and with biomagnification of persistent organic pollutants and methyl mercury already affecting fisheries. Indigenous and local communities, where food safety monitoring is underdeveloped, are the most vulnerable to these risks. 

Climate change and extreme weather events can disrupt the integrity of the food supply chain. They affect agriculture, fisheries and aquaculture. Warming has altered the distribution, growing area suitability and timing of key biological events, such as flowering and insect emergence, impacting food quality and harvest stability. Hurricanes, floods and droughts can damage crops, contaminate water supplies compromising the efforts to meet human needs.

Climate-Resilient Food Systems to Secure Food Supply

This IPCC report emphasises the importance of adaptive measures and sustainable practices. It recommends implementing climate-resilient agricultural techniques, such as diversifying crops, improving irrigation systems, and promoting soil conservation. The report also stresses the need for enhanced monitoring and surveillance of foodborne diseases, along with robust food safety regulations and standards. It underscores the urgency of adopting climate-smart strategies and policies to mitigate risks, safeguard food security, and protect human health.

What are the Main Emerging Food Safety Risks Linked to Climate Change?

Mycotoxins Contamination and Climate Change

Occurrence patterns of fungal growth and formation of mycotoxins will evolve due to variation in CO2 levels, temperature, and moisture. According to the latest scientific publications, future rises in global temperatures (2–5°C) and further increases in CO2 levels (350–400 ppm to 650–1200 ppm) will have a significant impact both on plant growth and on mycotoxin-producing fungi. Research has demonstrated that even a slight elevation of CO2 levels will stimulate the growth of mycotoxin-producing fungi. There is an increased risk for mycotoxin contamination of maize, wheat, and other small grain species. In changing climates, mycotoxins will contaminate new crops and different geographical areas. Countries with temperate climates (Europe, North/South America, Asia, Africa) will run the highest risk of increased mycotoxin contamination of crops.

Microbes and Climate Change

One key finding of the report is that rising temperatures are leading to increased microbial contamination of food. Which poses a significant risk to human health. Warmer temperatures promote the growth and survival of pathogens like Salmonella and Vibrio, increasing the occurrence of foodborne illnesses. According to scientists, over half of known human pathogenic diseases can be aggravated by climate change. The report also highlights the potential for altered precipitation patterns and extreme weather to impact food safety and contamination of crops and water.

Veterinary Drug Residues Increase

With higher risks of emerging zoonoses, resistance of pathogens, and alterations of vector-borne diseases and parasites in animals, an increased use of veterinary drugs might be needed. This can result in increased residue levels of veterinary drugs in foods of animal origin. This poses not only acute and chronic risks to human health, but is directly linked to an increase in antimicrobial resistance (AMR) in human and animal pathogens.

Moreover, climate change impacts the degradation and persistence of these residues in the environment. These factors might contribute to higher concentrations of veterinary drug residues in ecosystems. Generating risks for aquatic life and potentially impacting human health through contaminated food and water sources. Addressing this issue requires sustainable farming practices, proper waste management, and monitoring systems.

Pesticides Evolution

According to the WHO, the application of pesticides, and the subsequent residues in food, is an ongoing concern that is expected to become more prevalent due to climatic changes, with shifts in farming systems and farmers’ behaviour to adapt to the changing climate.

Increasing temperatures, altered rainfall patterns, and shifts in pest dynamics impact pesticide use in agriculture. Higher temperatures can enhance pesticide degradation rates, reducing their efficacy. Changes in precipitation patterns can lead to runoff and increased pesticide leaching into water bodies, posing risks to aquatic ecosystems. Additionally, climate change can influence pest resistance and the need for higher pesticide doses. Addressing these challenges requires adaptive pest management strategies, sustainable agricultural practices, and the development of climate-resilient pest control methods. The objective being to minimise pesticide residues and protect environmental and human health.

Chemical Hazards Increase

The increased frequency of inland floods linked to climate change will impact environmental contamination and chemical hazards in foods through the remobilisation of contaminated river sediments and subsequent contamination of agricultural and pastureland soil contaminants. Increasing heavy metal levels (including methylmercury, as methylation of mercury is temperature-dependent) in the environment arise from industrial activities, mining, agriculture, and waste disposal. Climate change exacerbates this issue by accelerating metal release, altering their bioavailability, and affecting their toxicity. Extreme weather events can spread heavy metals, while changing precipitation patterns impact water quality. Rising temperatures and droughts intensify health risks associated with heavy metal exposure. To address this, reducing emissions, adopting cleaner production methods, implementing proper waste management, and enhancing monitoring systems are crucial. Understanding the connection between heavy metals and climate change enables us to work towards sustainable practices that safeguard the environment and human health.

Marine biotoxins

Rising sea temperatures, altered oceanic currents, and increased CO2 levels contribute to the growth of harmful algae blooms leading to higher concentrations of biotoxins in the marine food chain. This poses risks to marine life and human health through contaminated seafood consumption. In this sense, the EFSA performed the Ciguatera risk assessment where factors such as climate change, warmer ocean temperatures, and alterations in marine ecosystems were identified as contributing to the increased prevalence of harmful algal blooms responsible for ciguatoxin production.

The European Food Safety Agency (EFSA) developed a methodology to identify and define emerging risks for food and feed safety, plant and animal health and nutritional quality related to climate change: CLEFSA– (“Climate change as a driver of emerging risks for food and feed safety, plant, animal health and nutritional quality”), it included “score sheets” that characterise possible effects climate change could have on a wide range of food safety-related issues.

According to scientists a key next step will be to compile global databases of empirical measurements and modelling information on the effects of Climate Change on contaminants for better informed predictions of future impacts, to support ecosystem-based planning decisions, to identify where pressing mitigation efforts are most needed, to plan proactive and more preventive management practices, and to monitor progress towards sustainable management actions.