IPCC Assessment in depth, Part 7: What does the IPCC report say about public health, conflict and migration?
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- Published on March 7th, 2022
The threat that climate change poses to human well-being and the health of the planet is “unequivocal”, says the latest report from the United Nations’ Intergovernmental Panel on Climate Change (IPCC). In this in-depth Q&A series, Carbon Brief unpacks the key findings of the report and the developments since the IPCC’s last assessment. (Read previous section here)
7. What does the IPCC report say about public health, conflict and migration?
The SPM states with very high confidence that climate change has adversely affected the physical health of people worldwide and the mental health of people in assessed regions.
One of the more obvious impacts of climate change on human health is extreme heat – which is linked to severe dehydration, organ failure, cardiovascular disease and even death, the report says.
However, it emphasises that the impacts of heat stress are not spread equally across the world. Some regions – including parts of India, the Persian Gulf, the Gulf of California and the southern Gulf of Mexico – are especially hard hit, and are “already experiencing heat stress conditions approaching the upper limits of labour productivity and human survivability”.
Since the AR5 in 2014, greater evidence has also emerged of the detrimental impacts of climate change on mental health, the report says. Heat is “one of the best-studied aspects of climate change observed to reduce wellbeing”, according to the report. It says that increasing temperatures are linked to higher hospital admissions for mood and behavioural disorders, “experiences of anxiety, depression, and acute stress” and suicide rates.
The report emphasises that extreme weather events, such as heatwave, wildfires, floods and droughts, are already becoming more frequent and intense – driving rising mortality rates. Over 1998-2017, there were 526,000 deaths from 11,500 extreme weather events globally, it says.
Disruption to infrastructure and basic services in the aftermath of extreme weather events can also be highly damaging for the affected communities. The disruption is often associated with increased violence against women, girls and vulnerable groups – including “increased risk of domestic violence, harassment, sexual violence and trafficking”.
Research also finds that extreme weather events, such as floods, heatwaves and wildfires, can trigger post-traumatic stress disorder, anxiety, and depression. The report adds that “sub-Saharan African children and adolescents, particularly girls, are extremely vulnerable to negative direct and indirect impacts on their mental health and wellbeing”.
The climate is also a driving factor in the spread of a range of diseases, the authors say. For example, the range of mosquitoes is expanding as temperatures rise, allowing mosquito-borne diseases, such as dengue fever and malaria, to spread to new areas.
The map below shows the projected changes in potential abundances of Aedes aegypti – a mosquito that can spread dengue fever, Zika and yellow fever – over 2090-99, under a scenario of around 2C of warming by 2100 (top, RCP2.6) and a scenario of very high emissions (bottom, RCP8.5).
The report projects that climate change will increase the risk of dengue fever in all continents. Compared to 2015, an additional 1 billion people are projected to be at risk of dengue exposure by 2080 under a mid warming scenario (described as “RCP4.5/SSP1”), and 5 billion under a high warming scenario (“RCP8.5/SSP3”), the report finds.
Warming combined with an increase in heavy rainfall and flooding is already increasing the incidence of diarrheal diseases such as cholera, the report finds. Meanwhile, the incidence of waterborne diseases is expected to increase in Africa in the coming decades due to rising temperatures and drought.
The report projects that by 2050, an extra 250,000 deaths each year from “climate-sensitive diseases and conditions” will be “attributable to climate change” (compared to the 1961-91 average, under a mid-emission scenario).
Excess deaths will be dominated by heat deaths in Asia and high income countries, childhood undernutrition and diarrheal disease in Africa and Asia and malaria in Africa, it says. Overall, more than half of the excess mortality will be seen in Africa, it adds.
The figure below shows the projected additional annual deaths from dengue, diarrheal diseases, malaria, heat and undernutrition attributable to climate change in 2030 and 2050, compared to a 1961-90 baseline.
For each region, the two bars show the additional deaths attributable to dengue fever (dark blue), diarrhoea (orange), malaria (light blue), heat (red) and undernutrition (green), in 2030 (left) and 2050 (right). The total deaths in each continent in 2030 and 2050 are shown by the black and white circles.
The report also says that Covid-19 has “aggravated climate risks”. For example, when extreme events struck, social distancing rules reduced the capacity of temporary shelters. The pandemic shows “the interconnected and compound nature of risks, vulnerabilities, and responses to emergencies”, the report says.
Meanwhile, the authors say there is high confidence that “climate hazards are a growing driver of involuntary migration and displacement and are a contributing factor to violent conflict”. Extreme weather events can drive migration in two ways, the report says – for example, directly through a cyclone destroying a house, or, for example, indirectly from long-term losses due to drought.
Most climate-related migration occurs within national boundaries, according to the report, which says that an average of 20 million people per year have been displaced internally by weather-related extremes since 2008. It adds that storms and floods rank as the most common drivers of displacement.
The figure below shows the number of people displaced every year over 2010-20 by extreme weather events, grouped by continent.
South, east and south-east Asia have seen the highest number of people displaced per year – largely to tropical cyclones and “extreme storms” – followed by sub-Saharan Africa, the report says. It also highlights that small-island states in the Caribbean and South Pacific are disproportionately affected, relative to their small population size.
The report adds that refugee and internally displaced people settlements are “disproportionately concentrated in regions that are exposed to higher-than-average warming levels and specific climate hazards, including temperature extremes and drought” – such as “the Sahel, the near east and central Asia”.
As the planet warms, migration is likely to increase, the report finds. For example, for every 1C of extra warming, the global risk of involuntary displacement due to flooding increases by 50%.
In the latter half of this century, current emissions pathways will put hundreds of millions of people at risk of displacement due to hazards including rising sea levels, floods, tropical cyclones, droughts, extreme heat and wildfire, according to the report. However, it adds that numbers are strongly dependent on socioeconomic conditions.
For example, displacement in Latin America, sub-Saharan Africa and South Asia by 2050 could vary between 31-143 million people depending on future emissions and socioeconomic development trajectories.
In addition to geographic inequality, the report highlights the gender inequality in migration:
“Women tend to suffer disproportionately from the negative impacts of extreme climate events for reasons ranging from caregiving responsibilities to lack of control over household resources to cultural norms for attire.”
Climate change is also expected to reduce water availability. Existing literature linking water insecurity to conflict is limited, but the report says “the large majority acknowledges” that limited water availability can “exacerbate tensions”. For example, in Syria, drought has aggravated existing water and agricultural insecurity – but the report says that “whether drought caused civil unrest in Syria remains highly debated”.
The report cites analysis which suggests that 2C warming would increase the probability of “conflict risks” by 13%, due to reduced food and water security, and disruption to lives and livelihoods. This instability can lead to “civil unrest” in some regions, which is often linked to an increase in violence against women, girls and vulnerable groups, the report warns.
The report concludes that “climate-related migration outcomes are diverse”, adding that future migration and displacement patterns will depend on “not only on the physical impacts of climate change, but also on future policies and planning at all scales of governance”.
Next: How does climate change affect poverty and progress towards the sustainable development goals?
All sections:
- What is the IPCC report?
- How is climate change affecting land ecosystems?
- What impact is global warming having on marine life?
- How is climate change affecting the world’s water?
- What does the IPCC report say about impacts on food and agriculture?
- What risks does climate change pose to the world’s cities?
- What does the report say about public health, conflict and migration?
- How does climate change affect poverty and progress towards the sustainable development goals?
- How is the world adapting to climate change?
- What the latest IPCC report says about carbon fee and dividend
Authors:
Aruna Chandrasekhar holds an MSc in environmental change and management from the University of Oxford. She previously worked as a freelance journalist for a variety of publications, including the New York Times, Guardian, Scroll and Caravan.
Daisy Dunne holds a BSc in biology from the University of Bristol and a science journalism MA from City, University of London. She was The Independent’s climate correspondent from November 2020 to 2021. Prior to this, she was Carbon Brief’s science writer from 2017 to 2020.
Josh Gabbatiss covers climate and energy policy. Josh holds a BSc in zoology from the University of Bristol. He previously worked as science correspondent at The Independent and prior to that was a freelance journalist for a variety of scientific publications including New Scientist and BBC Earth.
