The health of hundreds of millions of people around the world is already being damaged by climate change, a major report has revealed.
Heatwaves are affecting many more vulnerable people and global warming is boosting the transmission of deadly diseases such as dengue fever, the world’s most rapidly spreading disease. Air pollution from fossil fuel burning is also causing millions of early deaths each year, while damage to crops from extreme weather threatens hunger for millions of children.
The findings, published in the Lancet journal, come from researchers at 26 institutions around the world, including many universities, the World Health Organization, World Bank and the UN’s World Meteorological Organization (WMO). The WMO reported on Monday that the level of carbon dioxide in the atmosphere made a record jump in 2016 to hit a concentration not seen for more than three million years.
“Climate change is happening and it’s a health issue today for millions worldwide,” said Prof Anthony Costello, at the World Health Organization and co-chair of the group behind the new report. It follows a related report in 2009 that warned that climate change was the biggest danger to global health in the 21st century, an assessment repeated in the new report.
But Costello said acting to halt global warming would also deliver a huge benefit for health: “The outlook is challenging, but we still have an opportunity to turn a looming medical emergency into the most significant advance for public health this century.”
“Our scientists have been telling us for some time that we’ve got a bad case of climate change. Now our doctors are telling us it’s bad for our health,” said Christiana Figueres, who as the UN’s climate chief negotiated the Paris climate change agreement and also co-chaired the new report.
“Hundreds of millions of people are already suffering health impacts as a result of climate change,” she told the Guardian. “Tackling climate change directly, unequivocally, and immediately improves global health. It’s as simple as that.”
One of the most striking of the 40 indicators assessed by the researchers was a huge increase in the number of people over 65 exposed to extreme heat. This rose by 125 million between 2000 and 2016 and worries doctors because older people are especially vulnerable to heat.
“There is no crystal ball gazing here, these are the actual observations,” said Prof Peter Cox, at the University of Exeter, UK. He said the 70,000 deaths that resulted from the 2003 heatwave in Europe looked small compared to the long-term trends: “We were alarmed when we saw this.”
Most of the increase in exposed people resulted from rising temperatures, but the number of older people is also rising, creating a “perfect storm”, Cox said. The report also found that hotter and more humid weather was increasingly creating conditions in which it is impossible to work outside. In 2016, this caused work equivalent to almost a million people to be lost, half in India alone.
The report also found that climate change has increased the ability of dengue fever to spread, because the mosquitoes and the virus they carry breed more quickly. Dengue is also known as “breakbone fever” due to the pain it causes and infections have doubled in each decade since 1990, now reaching up to 100 million infections a year now. Dengue was used as an example in the report and the researchers suggest global warming will also increase the spread of other diseases such as schistosomiasis.
Air pollution is known to cause millions of early deaths every year but the new report highlights the 800,000 annual deaths related solely to coal burning. The good news here, said Prof Paul Wilkinson, is that coal production peaked in 2013 and is now falling. “We are seeing the first turn [in the trend] but we have a long way to go,” he said. “It is a health dividend we are ignoring if we do not act.”
The impacts of climate change are not limited to poorer nations, said Dr Toby Hillman, at the Royal College of Physicians, but also affect developed nations like the UK. He said air pollution kills about 40,000 in the UK each year and criticised low government funding levels for cycling and walking. Hillman also noted other impacts, such as sharp increases in mental health problems after extreme weather events like flooding.
The new report highlighted imminent threats as well, such as the loss of crops to increasingly hot and extreme weather. “We are going to see millions more undernourished children as a result of that,” said Prof Hugh Montgomery, at University College London (UCL).
Montgomery said the potential benefits of climate change appeared to be small in comparison to the damages: “We are not ducking the potential benefits, we just find it hard to see what they are.”
Cox said it was not clear that global warming will actually reduce winter cold spells, which cause early deaths in higher latitude countries, because changes happening in the Arctic can exacerbate cold snaps. Prof Georgina Mace, also at UCL, said the evidence for a warmer climate increasing food production was often very localised and short term: “Overall the overwhelming pattern is negative.”
Clare Goodess, a climate researcher at the University of East Anglia and not part of the Lancet report, said: “The indicators reveal some stark warnings for human health, as well as some glimmers of hope, [and] the key messages appear robust. The attribution of [climate change] temperature trends to human activities is now unequivocal, so the urgency of addressing the issues raised by this report is not in doubt.”