Heat, disease, air pollution: How climate change impacts health

PARIS, France — Growing calls for the world to come to grips with the many ways that global warming affects human health have prompted the first day dedicated to the issue at crunch UN climate talks starting next week.

Extreme heat, air pollution and the increasing spread of deadly infectious diseases are just some of the reasons why the World Health Organization has called climate change the single biggest health threat facing humanity. 

Global warming must be limited to the Paris Agreement target of 1.5 degrees Celsius "to avert catastrophic health impacts and prevent millions of climate change-related deaths", according to the WHO. 

However, under current national carbon-cutting plans, the world is on track to warm up to 2.9C this century, the UN said this week. 

While no one will be completely safe from the effects of climate change, experts expect that most at risk will be children, women, the elderly, migrants and people in less developed countries which have emitted the least planet-warming greenhouse gases. 

On December 3, the COP28 negotiations in Dubai will host the first "health day" ever held at the climate negotiations. 

This year is widely expected to be the hottest on record. And as the world continues to warm, even more frequent and intense heatwaves are expected to follow.

Heat is believed to have caused more than 70,000 deaths in Europe during summer last year, researchers said this week, revising the previous number up from 62,000.

Worldwide, people were exposed to an average of 86 days of life-threatening temperatures last year, according to the Lancet Countdown report earlier this week.

The number of people over 65 who died from heat rose by 85 percent from 1991-2000 to 2013-2022, it added.

And by 2050, more than five times more people will die from the heat each year under a 2C warming scenario, the Lancet Countdown projected.

More droughts will also drive rising hunger. Under the scenario of 2C warming by the end of the century, 520 million more people will experience moderate or severe food insecurity by 2050.

Meanwhile, other extreme weather events such as storms, floods and fires will continue to threaten the health of people across the