How climate change impacts health—and what we need to do about it

We need to respond to the climate crisis together, in solidarity with all, for the health of all.

An MSF staff member wearing a white vest stands in the middle of floodwater surrounded by palm trees in Venezuela.

Venezuela 2021 © Matias Delacroix

Extreme weather events caused by climate change are happening all over the globe with, greater frequency and force. It has already had a disastrous impact on people’s health. 

By Dr. Maria Guevara, MSF international medical secretary


At Doctors Without Borders/Médecins Sans Frontières (MSF), we see the impacts of climate change each and every day in our work providing medical care to people in more than 70 countries around the world.

This year, in the Asia Pacific region, powerful Cyclone Mocha hit Myanmar and Bangladesh and destroyed communities, including refugee camps. In years past, we saw strong typhoons submerge homes and destroy properties, such as Haiyan in 2013, which laid waste to the central Philippines and caused widespread flooding in Indonesia.

Other impacts of climate change are evident around the globe. July 2023  was recorded as the planet’s hottest month in 174 years. As a result, we saw Canadian wildfires, major heatwaves in France, Spain, Germany, Poland, and Italy, and marine heatwaves along coastlines from Florida to Australia.

In short, extreme weather events are happening all over the globe with greater frequency and force.

Climate change and human health

MSF teams see the impact of climate change every day—from outbreaks of waterborne diseases to malnutrition, displacement, and other urgent issues related to health. 

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Climate change will increase disease outbreaks

MSF is responding to worryingly high levels of vector-borne, food-borne, and waterborne diseases in our projects—these types of health crises are projected to continue to increase with the climate crisis.

It is predicted that climate change will contribute to 15 million more cases of malaria yearly, including 30,000 deaths. One billion more people are expected to be exposed to dengue fever across the world. In fact, European Union officials recently warned that there is a growing risk of mosquito-borne viral diseases such as dengue and chikungunya in Europe due to climate change. We have also seen cholera outbreaks in at least 30 countries. While this is due to multiple factors, climate change is most definitely one of them.

A woman and child sit on a hospital bed behind a mosquito net in Nigeria
A mother and her child were treated for malnutrition at Kofar Sauri inpatient therapeutic feeding center in Katsina City. Nigeria 2022 © George Osodi/MSF

Food insecurity will lead to higher malnutrition rates

Climate change is also linked to health risks such as food insecurity and malnutrition. With extreme weather events such as heat waves and increased rainfall come droughts and floods that impact farming and fishing communities, affecting everything from the yield of crops, to the animals that till the soil and the number of fish caught in nets.

Conflict and displacement, non-communicable diseases and mental health—all impacted by climate change

The effects of climate change on health do not end there. Byproducts of climate change, such as poor nutritional options and air pollution, can increase non-communicable diseases, like heart disease. As places around the world become uninhabitable due to the climate, it will cause more forced displacement and migration. Fighting over scarce resources could lead to the emergence of conflicts. And as people struggle to process the consequences of climate change, we could see an increase in mental health needs.  And all of these issues are expected to intensify as the climate warms over time—unless we take urgent action.
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An MSF staff member measures the size of a child's arm in Madagascar, during a period of severe malnutrition.
A child stands on a scale to record his weight during an acute malnutrition crisis in Madagascar.

In 2021, MSF responded to an acute nutritional and food crisis in southeast Madagascar, the worst the region had seen in years. Madagascar 2021 © iAko M. Randrianarivelo/Mira Photo

The worst impacts of climate change on health are felt by the most vulnerable countries

Humanitarian organizations like MSF are already seeing the health impacts of climate change as we treat patients in the most vulnerable communities—from the Asia Pacific, to the Middle East, to Africa. But we can only do so much.

The climate crisis and resulting devastation impact countries with limited resources the most. Our Rohingya patients in Cox’s Bazar, Bangladesh—who have endured decades of persecution and are already burdened by their containment in the world’s largest refugee camps—are repeatedly threatened by flooding and cyclones that come their way. Our patients in the island nation of Kiribati face climate and environmental changes that threaten their livelihoods and exacerbate disease risks.

We have been sounding the alarm. We see these huge health care needs brought about by the climate crisis, and we fear that these needs are outstripping our capacity to respond.

Buzi, Mozambique - March 2019
Buzi, Mozambique - March 2019

Cyclone Idai caused catastrophic flooding in southeast Africa in 2019, leaving hundreds of thousands cut off from health care and other essential services. Mozambique 2019 © MSF/Pablo Garrigos

Governments must do more to respond to climate change

We need the countries most responsible for this global warming by 1.2 degrees above pre-industrial levels to help those who are most affected, take responsibility, and provide financial and technical support to the most vulnerable. Governments of the most affected countries must not only compel the top polluters to help mitigate and manage the effects of climate change, but also put in place policies and affirmative climate actions that address and reverse the impact of these issues.

Fortunately, we are already seeing commitments from world leaders. At their recent meeting, G20 nations committed to a greener and more climate-resilient health system. The Association of Southeast Asian Nations (ASEAN)—which includes five of the world’s 20 most at-risk countries—has announced an ambitious strategy to work towards carbon neutrality. The agenda for COP28 in November, the annual United Nations climate conference, has an increased focus on health, relief, and disaster response.

A white MSF vehicle gets stuck in muddy water on the way to Buzi, Mozambique.
MSF teams respond to the impacts of Cyclone Eloise. | Mozambique 2021 © MSF

This is an important and critically urgent moment. These commitments are ambitious, but member states of these regional blocs must see them through and take real action. Today, we are dangerously off track.

The climate crisis requires a collective approach. People and organizations must also understand that our own behaviors are a part of the problem. Climate change affects the health of us all, so we need to respond to the climate crisis together, in solidarity.