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Climate change and food safety

Climate change poses significant challenges to global food safety. Long-term changes in temperature, humidity, rainfall patterns and the frequency of extreme weather events are already affecting farming practices, crop production and the nutritional quality of food crops. The sensitivity of germs, potentially toxin-producing microorganisms and other pests to climate factors suggests that climate change has the potential of affecting the occurrence and intensity of some foodborne diseases. Also, changing conditions may favour the establishment of invasive alien species harmful to plant and animal health. Surface seawater warming and increased nutrients input leads to the profusion of toxin-producing algae causing outbreaks of seafood contamination.

Global efforts to reduce greenhouse emissions and regional measures to mitigate and adapt to changing climatic conditions will impact on EFSA’s assessments of food and feed safety in relation to human health and nutrition, animal and plant health, and the environment.


An international team of scientists led by EFSA have 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. The approach – called CLEFSA (“Climate change as a driver of emerging risks for food and feed safety, plant, animal health and nutritional quality”) – is described in a new report, which includes ‘scoresheets’ that characterise possible effects climate change could have on a wide range of food safety-related issues.

Experts from the following organisations and institutions and coordinators of relevant international projects took part: World Organisation for Animal Health, European Centre for Disease Control and Prevention, EuroCigua project, GlobalHAB programme, European Environment Agency, Food and Agriculture Organization, Intergovernmental Oceanographic Commission of UNESCO, Joint Research Centre, University of California, University of Florence, UN Environment Programme, World Health Organization, World Meteorological Organization, Consiglio Nazionale delle Ricerche.


2020 EFSA publishes the results of the CLEFSA Project describing a methodology for characterising the possible effects of climate change on emerging risks in the food safety area.

2018 EFSA launches its CLEFSA project (climate change as a driver of emerging risks for food and feed safety, plant, animal health and nutritional quality) and runs a climate change survey to gather insights on emerging issues potentially affected by climate change.

2018 EFSA supports the French Agency for Food, Environmental and Occupational Health and Safety and the European and Mediterranean Plant Protection Organization to organise a conference on “The impact of global change on the emergence of plant diseases and pests in Europe”.

2017 EFSA’s Executive Director Bernhard Url premieres EFSA video on mycotoxins and climate change at an International Conference in Rome and launches a project on mycotoxin mixtures in food and feed, including the study of the influence of climate change on mycotoxin production.

2016 European scientists join forces to fight ciguatoxin food poisoning outbreaks in Spain and Portugal.

2014 Climate change is identified as driver of the spread of apple snails in south European wetlands.

2013 EFSA assesses risks posed by viruses transmitted to plants by the silverleaf whitefly, under current conditions and a climate change scenario of +2°C.

2012 EFSA supports development of a tool for predicting the production and spread of aflatoxins in maize, wheat and rice under different climate change scenarios.

2011 EFSA holds a scientific colloquium on emerging risks in plant health focusing on “plant pest interactions to global change”.

2008 Joint EFSA-FAO-WHO Europe seminar on climate change and its health impacts on food/water safety and nutrition.


EFSA’s scientific risk assessments and other scientific advice cover a broad spectrum of sectors related to the food chain. Some of these areas are affected by climate change, particularly plant health, animal health, biological hazards and contaminants.

Plant and animal health

An alien species – animal, plant or micro-organism – is one that has been introduced as a result of human activity to an area it could not have reached on its own. Invasive alien species can create serious problems when entering new territories as for example pests in agriculture or vectors of diseases in animal husbandry. Climate change is one of several factors (others include the globalisation of trade, growth of tourism) that contribute to their spread and mutation.

Climate change is an established driver in the emergence of new plant pests and increased risks from known pests. EFSA held a scientific colloquium on plant pest interactions and global changes in 2011, which looked at climate change as a driver of emerging plant health risks. Our scientists have found evidence that climate change has been a factor in the emergence of several plant pest risks. For example, we concluded that the apple snail poses a threat to south European wetlands, with extreme weather events and flooding (influenced by climate change) increasing the natural spread of this pest via rivers and canals.

New pests can also arrive due to the climate-related movement ofdisease-carrying organisms (mainly insects and birds) known as vectors. For example, a 2013 assessment looked at risks posed by viruses transmitted to plants by the silverleaf whitefly. Our scientists constructed predictive models on the area of potential establishment and spread under current conditions and a climate change scenario of +2°C. Policymakers can use these results to define control and adaptation measures.


Vectors also transmit diseases and viruses to animals with damaging consequences for livestock and wildlife. Biting midges of the Culicoides genus are carriers of bluetongue, a viral disease affecting sheep, goats, cattle and deer. There is evidence that the midges advanced northwards into southern Europe from Africa as a result of increased humidity and temperature linked to global warming. The movement of blood-feeding flies, mosquitoes and ticks are responsible for the spread of lumpy skin disease from the Middle East to south-east Europe. Temperature and humidity are key factors in the abundance of these vectors and the risk of its further spread.

In our work on bee health, EFSA scientists initiated efforts to develop a model to assess risks to honeybee colonies from exposure to pesticides under different scenarios of combined stressors and drivers, including the influence of climate on the honey bee colony. The model will help to clarify the relative importance of different stressors, e.g. how does the impact of a pesticide on colony health change with changing climate. The collection of data (including climate data) is accompanying the model development.


The transmission of infections or diseases between animals and humans (“zoonotic diseases”) is a major source of food safety risks. Environmental factors such as temperature, rainfall, humidity levels and soil can help to explain the distribution and survival of bacteria such as Salmonella and Campylobacter. The presence of norovirus (“the winter vomiting bug”) in oysters from sewage runoffs caused by heavy rainstorm and flooding may also linked to the increasing frequency of extreme weather events due to climate change.


EFSA’s assessments of environmental contaminants includes several naturally occurring toxins produced by fungi and plankton. Increases in the presence of these toxins and/or their appearance in new geographical locations has been linked to climate change in some cases.

Certain species of fungi produce chemicals called mycotoxins, some of which can be highly toxic. They can affect the health of infected plants and enter the food chain via contaminated food and feed crops (cereals, legumes, nuts). Temperature and humidity are important factors influencing fungal growth, crop infection and mycotoxin toxicity. Climate change is considered a driver of recent changes in the occurrence of mycotoxins in Europe.

For example, aflatoxins are carcinogenic mycotoxins produced by two species of Aspergillus, a fungus found in areas with hot and humid climates. Rising temperatures and humidity linked to climate change probably contributed to the appearance of aflatoxins in southern Europe in the early 2000s and their steady spread northwards since then. In 2012 EFSA helped to develop a tool for predicting the production and spread of aflatoxins in maize, wheat and rice under different climate change scenarios. Also, mycotoxins often occur in nature in mixtures, potentially interacting and increasing the risks for animals and humans. Our scientists are supporting research to help develop flexible risk assessment modelling approaches for mycotoxin mixtures. This includes studying the impact of environmental variables related to climate change (e.g. temperature, pest attack, nutrient availability) on mycotoxins production and their occurrence in food.

Climatic variables also have a huge impact on the presence of phytoplankton. These microscopic marine and freshwater algae are a mainstay of the diet of many fish and other marine life. Some of them, however, can be highly toxic and lead to seafood poisoning. One of them is ciguatera, typically present in tropical areas. Since 2008, several outbreaks of ciguatera fish poisoning have occurred in Spain (Canary Islands) and in Portugal (Madeira) with climate change a likely cause. EFSA is supporting national partners who are collecting data on environmental factors (temperature rises, increased salinity) affecting the toxicity of ciguatera and developing models to predict blooming, accumulation in fish and future outbreaks using different climate scenarios. Also, an increase in indigenous marine bacteria such asVibriothat can produce toxins in molluscs may be due to rising sea water and temperatures.

Cyanobacteria are naturally forming bacteria that bloom on fresh and seawater surfaces. They boast a range of nutritional properties and are used as ‘natural’ food supplements. However, some have toxic properties that are expected to multiply due to global warming and other environmental factors such as nutrient availability.

CLEFSA Project

EFSA’s project on “Climate change as a driver of emerging risks for food and feed safety, plant, animal health and nutritional quality” (CLEFSA) ran from 2018 to 2020. The CLEFSA project helped to build on our previous experiences of climate change-related risk assessments and our strong networks with national and international partners, the scientific community and other stakeholders on emerging risks and their drivers. We also looked at issues identified in the context of EFSA’s emerging risks identification process.

The CLEFSA project aimed to develop methods and tools to identify and define emerging risks related to climate change through:

  • long-term anticipation of multiple emerging risks using scenarios of climate change;
  • horizon scanning and crowdsourcing to collect signals from a variety of information sources;
  • enlarging the knowledge network to experts from international EU and UN agencies;
  • designing “multi-criteria decision analysis” tools to define risks in food, feed safety, plant, animal health and nutritional quality.

The CLEFSA network included experts from international, EU and UN institutions and coordinators of large EU projects involved with climate change. The group helped to identify emerging issues and design the multi-criteria decision analysis tool. EFSA had already used criteria for emerging risks identification and adapted these to the specific driver of climate change.

We published a report on the outcomes of the CLEFSA project in June 2020.


Under Article 34 of EFSA’s Founding Regulation 178/2002, the Authority is required to:

  • identify, assess and disseminate information on emerging issues and ensure coordination with relevant networks and international organizations;
  • promote the identification of data sources and data collection and/or data generation in prioritized emerging issues; and
  • evaluate the collected information and identify emerging risks.

The drivers of emerging risks include population growth, globalisation, resource and energy scarcity, slowing agricultural productivity, increasing concentration of the supply chain, price volatility, changing diet trends and the emergence of anti-microbial resistant strands.

Climate change is a relevant driver of emerging risks. A broad range of studies and reports examine the impact of climate change on food security, by stressing the pressures on food production for a growing human population. Less scientific research and public policy have focused on future challenges for food safety and nutrition quality as a result of climate change. EFSA aims to fill part of this void through its emerging risks activities.

EU framework

The EU and Member States are committed to transforming Europe into an energy efficient and low-carbon economy by 2050, cutting emissions by 80-95% compared to 1990 levels. As well as reducing carbon emissions and fighting global warming, the EU’s climate action framework includes EU and national strategies for climate adaptation. Several of these are linked to food and feed safety, e.g. developing drought-tolerant crops, new irrigation infrastructure, rescheduling planting times, using additional fertilizers.

Other important initiatives at European level include:

  • The European Climate Adaptation Platform (Climate-ADAPT) is a partnership between the European Commission and the European Environment Agency (EEA). EEA has also published an extensive report on the challenges and opportunities of Climate change adaptation in the agriculture sector in Europe.
  • The European Commission’s Group of Chief Scientific Advisors (GCSA) is a key element of the Scientific Advice Mechanism (SAM) that provides the College of Commissioners with independent scientific advice on specific policy issues. The GCSA is developing a scientific opinion on an EU sustainable food system that will take account of climate change-related health impacts in Europe.
  • The European Academies’ Science Advisory Council – composed of National Academies of Science of the EU Member States, Norway and Switzerland – recently published a report on The imperative of climate action to protect human health in Europe which details opportunities for adaptation to reduce the impacts of climate change, and for mitigation to capitalise on the benefits of decarbonisation.

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