UN Warns That Climate Change Bring Frequent And Intense Heat Waves

A United Nations expert warned that climate change was permitting increasingly powerful and long-lasting heatwaves, which could soon become year-round in some locations.

Extreme heat has dominated the news in recent weeks, from the current "heat dome" that is heating up much of Europe to heat-fueled wildfires raging in Greece, Spain, Canada, and Hawaii, as well as soaring temperaures in the heart of South America's winter.

John Nairn, a senior extreme heat advisor at the UN's World Meteorological Organization, observed that heatwaves are becoming more intense.

"It's the most rapidly emerging consequence of global warming that we are seeing in the weather systems," he said in an interview.

New normal

The UN World Meteorological Organization said that heatwaves sweeping broad portions of the world serve as another reminder that extreme weather events exacerbated by human-caused climate change have become "the new normal."

Weather agency spokesperson Clare Nullis noted that heat warnings have been issued by various weather services across Europe this week, including in France, Germany, Poland, and Switzerland.

Meanwhile, temperatures in parts of the Middle East were forecast to reach 50 degrees Celsius in the next few days, and Japan was suffering a "prolonged" heatwave that broke temperature records.

"Unfortunately, that is a picture with which we've become all too familiar this summer," she said.

Nairn observed that global warming looks to be weakening the global jet streams, which carry air high in the Earth's atmosphere.

As the jet stream waves slow and wavier, weather systems can "park" in one place for prolonged periods of time. When viewed as a whole, he claims that "these heatwaves are appearing in each of those same wavelengths around the globe."

"The slowing down and parking of the weather patterns is setting us up so that North America, parts of the Atlantic ocean, Europe and Asia are simultaneously sitting in the (wave) ridges, getting caught," he said.

Smart discourse

Nairn urged that the discourse around heat become "smarter."

Among other things, he believes that the focus should be on rising nighttime minimum temperatures rather than the headline-grabbing maximum day temperatures.

Repeatedly high evening temperatures are especially hazardous to human health because the body is unable to recoup from the heat it endures during the day.

Higher overnight temperatures also mean that the energy produced throughout the day has nowhere to go, causing temperatures to rise even higher the next day.

Because minimum temperatures are rising faster than maximum temperatures, extra energy is being pushed "into longer periods of higher temperatures," according to Nairn.

He also expressed special alarm about the situation in the tropics and subtropics, citing South America's record heat, with temperatures reaching 40 degrees Celsius in the middle of what is supposed to be their winter.

In the future, he warns, "we're going to see a lot more heatwaves across a much longer period of the year."

In the tropics and subtropics, "unfortunately, indications are that severe and extreme heatwaves are likely to be able to occur anytime (of year) before the end of the century."