‘Blown away': Safe climate niche closing fast, with billions at risk

As much as one-third of the world's population will be exposed to Sahara Desert-like heat within half a century if greenhouse gas emissions continue to rise at the pace of recent years.

Dust storm near Orange, NSW in January. The relatively stable climate
that has supported human civilisation for the past six millennia
 is likely to shift in the next 50 years because of climate change.

Scientists from China, the US and Europe found that the narrow climate niche that has supported human society would shift more over the next 50 years than it had in the preceding 6000 years.

As many as 3.5 billion people will be exposed to "near-unliveable" temperatures averaging 29 degrees through the year by 2070. Less than 1 per cent of the Earth's surface now endures such heat.

That heat compares with the narrow 11- to 15-degree range that has supported civilisation over the past six millennia, according to research published Tuesday in the journal Proceedings of the National Academy of Sciences.

Read the story from The Age by Peter Hannam - “‘Blown away': Safe climate niche closing fast, with billions at risk.”

Deadly Heat Waves Could Endanger 74% of Mankind by 2100, Study Says

Deadly heat waves—already a risk for 30 percent of the world's population—will spread around the globe, posing a danger for 74 percent of people on Earth by the end of this century if nothing is done to address climate change, according to a new study.

An increasing percentage of the planet faces deadly heat for 20 or
more days per year, with one-third of the world's population currently at risk

Nearly as alarming, the researchers project that even if greenhouse gases are aggressively reduced, at least 48 percent of the population will still face deadly heat waves by 2100 because of the amount of long-lived heat-trapping gases that already have accumulated in the atmosphere.

"We're running out of good options for the future," said lead author Camilo Mora, a biologist at the University of Hawaii at Manoa. "For heat waves, our options are now between bad or terrible.”

The new study comes as near-record heat is forecast for this week in California and the U.S. southwest, with the temperature expected to soar to 120 degrees in Phoenix, and as severe heat grips parts of Europe, contributing to forest fires that have killed at least 60 people in Portugal.

Read the Inside Climate News story by Marianne Lavelle - “Deadly Heat Waves Could Endanger 74% of Mankind by 2100, Study Says.”