How climate change impacts plant health - and why it matters for One Health

Across the world, climate change is shifting the delicate balance that keeps plants – and everything they support - healthy. As temperatures rise, rains become less predictable, and extreme weather strikes more often, plant pests and diseases are spreading in ways not seen before. The consequences reach far beyond crops. In a world where human, animal, plant and environmental health are deeply connected, protecting plant health has never been more critical.

The Scientific review of the impact of climate change on plant pests, produced by the Food and Agriculture Organization of the United Nations (FAO), with the International Plant Protection Convention (IPPC), highlights how climate change is creating new risks for plant health - risks that in turn affect food security, livelihoods, biodiversity and the stability of ecosystems.

New opportunities for pests, diseases and toxins

As the climate shifts, so do the threats to plant health. Warmer temperatures and milder winters are helping plant pests and diseases survive and spread into areas that were once too cold for them. The fall armyworm - originally native to the Americas - has reached Africa, Asia and parts of Oceania, destroying maize crops that are vital for both people and animals. Meanwhile, in southern Europe, Xylella fastidiosa is targeting olive trees, almond orchards and vineyards - its spread being fuelled by warmer winters and changing ecosystems.

Increasing temperatures, shifts in humidity, and cycles of drought and flooding affect crops and provide the perfect conditions for fungi to grow and contaminate food. Some of these fungi can then produce mycotoxins - potent toxins that are invisible and survive cooking and processing.

These are not distant risks. Changes in climate are already affecting the behaviour, severity and spread of plant pests and pathogens, and these changes are accelerating.

©FAO/Fanjan Combrink

Climate-driven risks to plant health affect One Health

When plant health suffers, the effects ripple across the web of life and into human and animal health. Plants provide vital ecosystem services - they stabilize soils, filter water, store carbon, regulate local climates, and sustain wildlife. But when plant pests and diseases, including invasive species, weaken plant health, these services begin to break down.

This loss of plant health impacts ecosystem stability affects animals directly. Invasive plants like Parthenium hysterophorus and Prosopis juliflora outcompete native vegetation, reducing forage quality and quantity for livestock. Locust outbreaks, driven by favourable climatic conditions, can strip landscapes bare, leaving herders without grazing lands. And when animals consume contaminated feed containing aflatoxins or other mycotoxins, their growth, fertility, and immunity are compromised.

For people, plant health decline can mean reduced food availability and greater food insecurity. Like with animals, it can also increase exposure to harmful substances such as toxins in contaminated staple crops like maize, groundnuts and sorghum, that can cause serious health issues. Beyond this, degraded ecosystems with poor plant life leave communities less able to cope with climate shocks like floods, droughts, and heatwaves.

Climate change accelerates the decline of plant health, and this unravels the ecosystem services that support human, animal and environmental health.

Early warning and international standards are key

In a changing climate, protecting plant health means acting earlier and smarter. Strengthening early warning systems and pest monitoring helps detect emerging threats before they spiral into crises. Systems like FAO’s Desert Locust Information Service (DLIS) show how timely surveillance can stop outbreaks from turning into crises.

International standards are equally vital. The International Standards for Phytosanitary Measures (ISPMs), developed under the IPPC, help countries prevent plant pests and diseases from spreading through global trade. Meanwhile, Codex Alimentarius standards protect food safety, setting maximum levels for contaminants like mycotoxins to reduce risks to human and animal health. Together, these frameworks provide the foundation for science-based action.

As climate change reshapes risks, early warning, early action, and strong international standards are essential to safeguard plants – and everything they sustain.

Find out more

• Scientific review of the impact of climate change on plant pests
• FAO's work on transboundary plant pests and diseases
• International Plant Protection Convention (IPPC)
• Five ways climate change is intensifying the threats to plant health

Originally published on the website of the FAO Animal Production and Health Division: How climate change impacts plant health