The effect on human health should be a major consideration for action on climate change, with emerging threats to our physical well-being set to continue as the planet heats up.
Global experts sounded the alarm before Cop28 in Dubai as the convention prepares to host a first health day dedicated to solutions to mitigate the effect of environmental change.
It is not just extreme weather events caused by climate disruption that exposes human frailty, but myriad associated health threats and the ability for nations to respond.
Tropical disease, heat exhaustion and chronic kidney disease are just some of the emerging health problems posed by a changing climate.
Maternal and neonatal health are also more vulnerable to extreme heat, as is mental health and chronic non-communicable disease such as diabetes and asthma.
“There is now clear evidence that climate change is harming human health, and indeed climate change has been described as the biggest threat to human health this century,” said Prof Elizabeth Robinson, director at the Grantham Research Institute on Climate Change and the Environment at the London School of Economics and Political Science.
“Climate change is leading to an increase in frequency, intensity and duration of heatwaves, which is linked to heatstroke and exacerbation of underlying cardiovascular and respiratory disease.
“As the planet continues to warm, resulting in more intense heatwaves and precipitation extremes, more people will be exposed to the health impacts of climate change and it will be ever harder to adapt.”
Too hot to work
Effective measures have already been taken to ease the threats from more prolific heatwaves.
In France in 2003, about 17,000 excess deaths were attributed to an intense heatwave, mainly in people over 65 years old, after eight consecutive days of temperatures above 40ºC.
In contrast, in 2019 there were two heatwaves in France and record high temperatures, but about 1,500 deaths.
That was due to measures to protect the most vulnerable elderly people living alone by introducing a heat alert system and a registry of those most at risk.
Changes to diet and the way we work could help reduce the effects of heatwaves in the future, said Prof Robinson, who is leading the working group for the Lancet Countdown on Health and Climate Change.
“We are only starting to understand the full extent to which workers' health is being harmed by the changing climate,” she said.
“People who work in high-exposure sectors such as construction and agriculture are more at risk of heat stress and workplace accidents.
“Farm workers have been found to be suffering from increased kidney disease, which seems to be linked to a combination of increased heat and dehydration.
“Other impacts increasingly being recognised include having less time to exercise safely outdoors, and negative impacts on mental health and mental well-being.
“Focusing on the health co-benefits of climate change is important, because the direct health benefits of reducing air pollution contribute to overall efforts to tackle climate change.
“By eating more balanced diets that include more fruit and vegetables and less meat, there would be a reduction in methane emissions and improved health.”
Additional 250,000 deaths a year
The World Health Organisation forecast another 250,000 additional deaths a year between 2030 and 2050 as a direct result of climate change.
Undernutrition due to failing crops and water scarcity is a major concern, as is the rise of tropical disease such as malaria and dengue fever.
The UAE will host a day dedicated to health, relief, recovery and peace at Cop28 in Dubai on December 3.
It will have a firm focus on healthcare adaptation, and the emirates will also sponsor a first health ministerial meeting as a global call to action on care.
Despite the challenges ahead, experts said there is plenty of hope. By reducing emissions of greenhouse gases, large gains can be achieved for health outcomes, particularly by slashing air pollution.
Dr Alice Bell, is head of Climate and Health Policy at the Wellcome Trust, and a contributor to the health day at Cop28.
“When we're making decisions about climate change, we normally think about it in terms of weighing up greenhouse gas emissions on one side and the flow of money and the economic impact on the other, but we're missing lives,” Dr Bell said.
"We're not looking with enough precision and detail about understanding the problem and unlocking solutions.
“The healthcare sector can help identify how awful the climate crisis is, and they will help us tackle it.”
Between 2000 and 2019, the WHO estimated deaths due to heat to be about 489,000 a year.
The highest burden was in Asia (45 per cent) and Europe (36 per cent). The extreme heatwaves across Europe in 2022 were estimated to claim more than 60,000 lives across 35 nations.
Air pollution is also worsened by heatwaves, with around 7 million premature deaths a year from poor air quality around the world.
“Practically the whole planet has experienced heatwaves this year,” said Prof Petteri Taalas in the annual World Meteorological Organisation’s State of Climate Services Report.
“The onset of El Nino in 2023 will greatly increase the likelihood of breaking temperature records further, triggering more extreme heat in many parts of the world and in the ocean.”
Improved climate related health services are starting to offset the threats to well-being in projects around the world.
Drought anticipation measures in Kenya are improving access to clean water, while food security and shock response systems are supporting at-risk communities in Mauritania and the Sahel.
Humanitarian organisations are crucial to the effectiveness of these projects.
Advanced monitoring of extreme weather systems and heatwaves are also helping nations prepare for adverse events across Europe and in Australia, the Pacific region and across the Americas.
But it is in conflict areas where populations are most likely to feel the intensity of climate change.
Conflict zones exposed
Joe Battikh, International Committee of the Red Cross sustainability expert and research fellow with the Centre for Climate Diplomacy, has worked on a study evaluating the impact of climate change and environmental degradation in conflict regions.
“We looked at three countries, Yemen, Syria and Iraq, and how environmental gradation in an already challenging situation has impacted health and eco-economies,” Mr Battikh said.
“There was a massive deforestation in the northern part of Syria, for example, where over 500,000 trees were removed.
“That causes issues with sandstorms as there are no more trees to hold soil to the ground.
“Last year, the region of the Levant between Syria and Iraq witnessed eight unprecedented sandstorms which had a huge impact on the health of people there.
“Schools were closed and in Iraq, three people died in one of the sandstorms because of respiratory issues.”
The Notre Dame Global Adaptation Initiative aims to help private and public sectors prioritise climate adaptation by lowering risk and enhancing readiness.
The university’s index of climate prepared nations found many nations were losing ground across 45 core indicators of vulnerability and readiness for climate change.
“If you looked at the bottom 25 countries that are the least capable to adapt to climate change,14 of those countries are in conflict,” said Mr Battikh, who is a research fellow at the Anwar Gargash Diplomatic Academy in Abu Dhabi.
“In conflict areas waste management is challenging, for example, people end up burning their garbage, releasing toxic air into communities, which causes cancer.
“There is good work being done in this region, regards sustainability and new, new methods of agriculture and farming and different ways to grow crops on a big scale without using the amount of water that we've used in the past historically.
“Hopefully that information can be shared across the region, so it is becoming a beacon of knowledge in terms of critical, efficient farming.”