World Not Ready For Rise In Extreme Heat, Scientists Say

Paris : About 3.8 billion people could face extreme temperatures by 2050, and tropical countries will bear the brunt, while colder regions will also need to adapt, scientists said Monday.

Cooling demand will increase “significantly” in giant countries such as Brazil, Indonesia and Nigeria, where hundreds of millions of people lack air conditioning or other means to beat the heat.

But scientists from Oxford University said even a modest increase in hot days could have a “serious impact” in countries not accustomed to such conditions, such as Canada, Russia and Finland.

In a new study, they looked at different global warming scenarios to predict how often people might experience temperatures considered uncomfortably hot or cold in the future.

They found that if global average temperatures rise 2 degrees above pre-industrial times, “the population exposed to extreme heat conditions is expected to nearly double” by 2050.

But most of the impact will be felt this decade as the world rapidly approaches the 1.5C mark, study lead author Jesus Lizana told AFP.

“The key takeaway from this is that the need to adapt to extreme heat is more urgent than previously recognized,” said environmental scientist Lizana.

“New infrastructure, such as sustainable air conditioning or passive cooling, needs to be built over the next few years to ensure people can cope with dangerous heat.”

Prolonged exposure to extreme heat can overwhelm the body’s natural cooling systems and cause symptoms ranging from dizziness and headaches to organ failure and death.

It is often called the silent killer because most heat deaths occur gradually because high temperatures and other environmental factors work together to weaken the body’s internal thermostat.

Climate change is making heatwaves longer and stronger, and access to cooling, especially air conditioning, will be vital in the future.

– ‘Dangerously inadequate preparation’ –

The study, published in the journal Nature Sustainability, predicted that 3.79 billion people worldwide could be exposed to extreme heat by the middle of the century.

This would “dramatically” increase energy demand for cooling in developing countries, where the worst health consequences will be felt. India, the Philippines and Bangladesh will be among the largest affected populations.

The most significant change in “cooling degree days” (temperatures high enough to require cooling such as air conditioning or fans) is predicted to occur in tropical or equatorial countries, particularly in Africa.

The Central African Republic, Nigeria, South Sudan, Laos and Brazil saw the largest increases in dangerously high temperatures.

“Simply put, the most disadvantaged people are the ones who will bear the brunt of this trend, which our study shows, on hotter days,” urban climatologist and study co-author Radhika Khosla told AFP.

But he added that richer countries in traditionally cooler climates also “face a big problem, even if most people don’t realize it yet.”

Countries such as Canada, Russia and Finland could experience sharp drops in “heating degree days” (temperatures low enough to require indoor heating) under the 2C scenario.

But even a modest increase in higher temperatures would be felt more severely in countries not designed to withstand the heat, the authors said.

In these countries, houses and buildings are often built to maximize sunlight and reduce ventilation, and public transport operates without air conditioning.

Some cold-climate countries may see a drop in heating bills, but over time those savings will likely be replaced by cooling costs, Lizana said, including in Europe where air conditioning is still rare.

“Rich countries cannot sit back and assume they will be fine; in many cases they are dangerously unprepared for the heat that will come in the next few years,” he said.