NUNZIUM

The Southern US, particularly Texas, experienced a lethal heatwave on June 17th, with temperatures reaching an unbearable 119F (48C). This extreme heat, which resulted in several deaths, was caused by a "heat dome," a ridge of high pressure that traps hot ocean air over a region. The heat dome, likened to a lid over a boiling pot, combined with an unusually warm Gulf of Mexico and the timing around the summer solstice, led to this extreme heat, explained John Nielsen-Gammon, Texas State Climatologist and director of the Southern Regional Climate Centre at Texas A&M University.

This alarming event is not isolated and is a clear indicator of the escalating impacts of climate change. Over the past century, Texas has warmed between half and one degree Fahrenheit, a subtle change with significant implications. If this trend persists, the Environmental Protection Agency (EPA) predicts a three to four-fold increase in days per year above 100F (38C) in Texas by the end of the century.

The human toll of such heatwaves is devastating, with extreme heat being the deadliest natural hazard in the US. Particularly vulnerable are children and adults over 65. In 2022 alone, heat-related illnesses claimed more than 275 lives in Texas, with the current heat dome causing at least a dozen deaths in Texas and Louisiana. A 2010 study revealed that a "wet-bulb" temperature of 95F (35C) at 100% humidity, or 115F at 50% humidity, marks the threshold where the human body struggles to maintain a healthy core temperature, increasing the risk of heat-related illnesses.

The economic implications are equally significant. Infrastructure upgrades to cope with future heatwaves come with a hefty price tag, with an estimated cost of US$66.5 bn (£52.7bn) for improving wind and solar resources in Texas by 2030.

Future projections are equally concerning. A 2021 report by Rutgers University suggests that three degrees of global warming could put 1.2 billion people at risk of heat stress annually. By 2070, four million Americans could be living outside "the ideal niche for human life," according to a joint effort between ProPublica and The New York Times.

The recent Texas heatwave is a stark reminder of the increasing frequency and intensity of global extreme heat events due to human-induced climate change. Over the past three weeks, a high-pressure ridge has caused temperatures to rise above 48C (120F) in parts of southern US and Mexico. Over 40 million people, including residents of Houston, San Antonio, and Austin, have been under excessive heat warnings.

The heatwave has strained Texas's energy grid due to increased air conditioner use. The burning of fossil fuels has made such extreme heatwaves at least five times more likely, according to Climate Central, a climate science non-profit. Andrew Dessler, a climate scientist at Texas A&M University, emphasizes the unusual early arrival of such extreme heat, making this one of the hottest Junes ever recorded in southern Texas.

Michael Wehner, a climate and extreme weather expert at Lawrence Berkeley National Laboratory, estimated that human-caused global warming made the Texas heatwave around 2.7C (5F) hotter. He warns, "Dangerous climate change is here, now." The current heatwave has not only claimed lives but also strained power grids, with power outages exacerbating the risks in cities like Memphis, where tens of thousands of residents remain without power following storms.

In conclusion, the recent Texas heatwave is a chilling reminder of the escalating impacts of climate change and a call to action to address its root causes. As we prepare for a future where such extreme heat events become increasingly common, the heat dome may have lifted, but the issue remains a burning concern.