Our uninhabitable planet

0
190

PROBLEM:
Despite the 2015 Paris Agreement to limit global warming to 1.5 degrees Celsius above pre-industrial levels, the current trajectory has Earth reaching 2.7 degrees by 2080 (Climate Analytics and NewClimate Institute, 2021).

The eight hottest years recorded are 2015 to 2022. The Lancet reported 489,000 people worldwide died directly from extreme heat in 2019.
Five years ago, climate scientists forewarned parts of the world would become uninhabitable.

North Africa and the Middle East suffer record breaking 47-53 degrees Celsius.

Spain and western Europe forecast 45C this week.

Temperatures in Asia are replicating 2022’s summer when 900 million Chinese suffered temperatures in the 40’s and 50’s for two months, killing crops, drying rivers, causing wildfires, and sending people underground.

In India and Pakistan, extreme heat kills, with 96 deaths in India this June, 46C with severe humidity.

Thirty-one straight days over 110F in Phoenix, Arizona last month; people hospitalized with third degree burns from the sidewalks.

At 4,000 feet in the Andes, South America is currently clocking one of the most extreme heat events: 38.9C in the Chilean Andine winter season.

With every one-tenth degree Celsius warming, another 140 million humans will be outside the “human climate niche” (zone of tolerable temperatures). Currently, nine per cent of humans (> 600 million) live outside this niche (Nature Sustainability, May 2023).

Humans cool down by sweating. Internal body heat is moved to the surface via blood vessels and cooled by sweat evaporating from our skin. The more humid the air, the less our sweat evaporates. Above a wet bulb temperature of 95F (high air temperature and humidity) we can no longer cool by sweating, and body temperatures rise steadily. When humid, air temperatures of 34C can speed heart rate. This cardiovascular strain occurs even before a person’s internal temperature increases.

More than 100 migrants have died from heat this summer along the U.S.-Mexico border. They report 226 rescues for dehydration and heat-related illness in the American Southwest in one week.

On Aug. 1, global sea surface measured 20.96 C, breaking documented records. Marine heatwaves in the UK are five degrees higher than normal. Other marine heatwaves: the North Atlantic (first ever), the Mediterranean and the Gulf of Mexico. Florida sea surface temperature is 38.44 C (normal 23-31C, NOAA).

Additional broken records this summer: the hottest day globally, the two hottest months in human history (June and July), record-low Antarctic sea-ice.

As our planet warms and sea levels rise: the 30 per cent of Americans and the 20 per cent of Canadians living coastally are moving, joining millions of climate refugees globally; melting Arctic permafrost releases dormant viruses; by 2030, Arctic waterways will be navigable, risking North American security.

Heat domes and heat waves increase because the physical boundaries for the jet stream are changing. The jet stream helps circulate warm air from the tropics to the poles and bring cool air from the poles to the tropics. Because the Arctic is warming four times faster than the rest of the planet, the temperature difference between the poles and the tropics is changing, creating “wobbly” jet streams, pushed beyond normal parameters. Climate-related changes to the jet stream could trigger multiple simultaneous extreme weather events, threatening global food security.

“The onset of El Niño will greatly increase the likelihood of breaking temperature records and triggering more extreme heat in many parts of the world and in the ocean.”