Some 50 million Americans have been placed under excessive heat warnings and heat advisories this past week as huge swathes of the United States have suffered record extended temperatures blamed on climate change.
Approximately 40 million people have been experiencing temperatures of 100F (38C) or hotter this past week, with more than 55% of the west experiencing “extreme” or “exceptional” drought conditions, according to the US Drought Monitor,
According to NASA, local ground stations reported record-breaking temperatures. On 15 June, the high temperature in Salt Lake City (42°C/107°F) tied the city’s all-time high for any day of the year.
Record highs for 15 June were set in Needles, California (49°C/121°F), and Kingman, Arizona (44°C/111°F).
High but not quite record-breaking temperatures were recorded in Las Vegas (46°C/114°F), Bishop, California (41°C/106°F), and Death Valley (51°C/124°F).
The soaring temperatures have stressed power systems, with grid operators urging residents to conserve energy in order to avoid triggering brownouts or outages. On Thursday, California governor Gavin Newsom an emergency proclamation, the “extreme heat peril”, that allows power plants to ramp up operations quickly to meet energy demands as people across the state crank up their air conditioning.
California power grid operators issued their latest “flex alert” for Friday, asking homeowners across the state to conserve energy in the late afternoon and evening when demand surges.
The heat has also strained power grids in California and Texas and fuelled concerns over the spread of wildfires.
Many cities across the American west have also opened cooling stations and hydration stations to keep people safe from the dangerous temperatures – and the hottest months of the year are still expected to come.
The heat has added to smoggy air conditions, the worst in years in some locations. On Tuesday, areas around Phoenix saw the worst air quality since data started being recorded in 1980, according to NASA.
Water in soils is also at a historic low point, which means there is little moisture to absorb the heat, creating even hotter conditions. Indeed, a two-decade-long dry spell that some scientists refer to as a “megadrought” has sucked the moisture out of the soil through much of the Western United States.
The heatwave and drought is attributable climate breakdown, researchers suggest: a study published last year in the journal Science that man-made climate change tied to the emission of greenhouse gases can be blamed for about half of the historic drought.
“Currently, climate change has caused rare heatwaves to be 3 to 5 degrees warmer over most of the United States,” Michael Wehner, a climate scientist at Lawrence Berkeley National Laboratory, wrote in an analysis published this week, adding that heatwaves are likely to get worse in the future.
In addition to extreme heat, the mega-drought already is drying up rivers, threatening salmon stocks and seeing reservoir levels plummet. On Wednesday, America’s largest reservoir, Lake Mead, registered its lowest level on record since it was filled in the 1930s.
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