Nearly 3.8 billion people could be exposed to extreme heat by 2050, with tropical nations and unprepared cooler countries both facing severe adaptation challenges.
PARIS: The world is dangerously unprepared for a rapid increase in extreme heat, scientists warned on Monday.
A new study projects that nearly 3.8 billion people could face extreme heat by 2050 if global temperatures rise 2°C above pre-industrial levels.
The population exposed to such conditions is projected to nearly double, with the most severe impacts felt this decade.
Demand for cooling will “drastically” increase in large tropical countries like Brazil, Indonesia and Nigeria.
Hundreds of millions in these regions currently lack access to air conditioning or other means to beat the heat.
The study, led by the University of Oxford and published in Nature Sustainability, looked at future warming scenarios.
It assessed how often people might experience temperatures considered uncomfortably hot or cold.
Lead author Jesus Lizana said the need for adaptation is more urgent than previously known.
“The key take away from this is that the need for adaptation to extreme heat is more urgent than previously known,” Lizana told AFP.
“New infrastructure, such as sustainable air conditioning or passive cooling, needs to be built out within the next few years.”
Prolonged exposure to extreme heat can cause symptoms from dizziness to organ failure and death.
It is often called a silent killer as most deaths occur gradually as high temperatures undermine the body’s thermostat.
Climate change is making heatwaves longer and stronger, making access to cooling vital.
The gravest health consequences will be felt in developing nations like India, the Philippines and Bangladesh.
Central African Republic, Nigeria, South Sudan, Laos and Brazil will see the biggest rise in dangerously hot days.
Co-author Radhika Khosla said the most disadvantaged people will bear the brunt of this trend.
But wealthier countries in cooler climates also “face a major a problem — even if many do not realise it yet”.
Nations like Canada, Russia and Finland may experience steep drops in cold days requiring indoor heating.
However, even a moderate rise in hotter temperatures would have a “severe impact” in countries not used to such conditions.
Homes in these regions are often built to maximise sunshine, and public transport frequently runs without air conditioning.
Lizana noted that cold-climate nations may see initial savings on heating bills.
Over time, these would likely be replaced by rising cooling costs, including in Europe where air conditioning is rare.
“Wealthier countries cannot sit back and assume they will be OK -– in many cases they are dangerously underprepared for the heat that is coming over the next few years,” he said.
