Texas’ Heatwaves and the Climate Shift Index

According to the Texas Department of State Health Services data, Texas had at least 279 heat-related deaths in 2022, the highest number since 1999.

Texas Tribune reports that 2022 was also the state’s second-hottest summer on record during the state’s worst drought in more than a decade, says John Neilson-Gammon, the state’s climatologist and one of the leading experts on the state’s increasingly hot summers (Nguyen and Douglas, 2023).

Climate change has caused the overall temperatures in the states to climb, with summer heat starting earlier in spring and last longer into autumn, increasing the risk of heat exhaustion and heatstroke for its residents, according to the article.

This year the state is once again seeing triple-digit temperatures across its cities. Electric Reliability Council of Texas (ERCOT), an organisation that operates the state’s grid, says that the heat could break energy records as residents turn up their air conditioners at full blast to cope with the oppressive heat.

CNN reports that ERCOT issued a weather watch from June 16 to 21, when power usage is expected to be high and to prevent pushing the state’s electric grid to its brink. The organisation says they expect the energy use to hit 81,000 megawatts surpassing the previous record of 80,148 megawatts (Gray, 2023).

From mid-June, the state could be experiencing temperatures of 10-15 degrees above normal for several days as more than 33 million Americans from Houston to New Orleans are under heat alerts.

The National Weather Service Heat forecasts that indexes near Houston and San Antonio could be as high as 120 degrees Fahrenheit.

USA Today reports that the state’s largest cities open emergency cooling centres within libraries and other public buildings for vulnerable residents to shelter. Residents in Texas and Louisiana are advised to drink plenty of fluids, stay inside air-conditioned rooms, and check on their relatives and neighbours (Thornton, 2023).

The weather services announced that Austin, Texas, Corpus Christi, Texas, New Orleans, and all of southern Louisiana would feel the scorching heat and warn of wildfire risks in some areas.

During an interview with Texas Monthly, John Neilsen Gammon says that 1970 to 1979 was the coldest decade for the state, but fast forward to 2011 to 2020, the state experienced the hottest decade on record.

“Starting with the eighties, every decade in Texas has been warmer than the decade before—1997 was the last year in which the Texas temperature was below the twentieth-century average. Every year since then has been warmer,” he says.

When asked about climate change’s role in increasing temperatures, Gammon states that the state’s rising temperature is “very close” to climate model simulations due to climate change and projects that the next 50 years will see a continuing warming trend. Texas is in the continental areas and will warm up faster than the rest of the globe.

According to Gammon, other effects of climate change include increased heat and humidity in areas close to the Gulf of Mexico, which could also raise the risk for wet bulb temperatures. For agriculture, the growing season will start early, the number of days with frost will decrease, and non-heat-tolerant crops will see a shorter growing season. Increased heat will also raise the rainfall intensity and the “risk of the strongest hurricanes”. Droughts will also become more frequent and severe.

Climate Central, a nonprofit group, uses a Climate Shift Index to show climate change’s influence on Texas’ heat waves. According to the organisation’s analysis, “human-caused climate change is making the near-record heat forecast in large parts of Texas and Mexico at least five times more likely” (Climate Shift, 2023).

Their researchers noted that several of the state’s cities had seen a significant temperature increase in recent years. Since the 1970s, Texas cities had a rising number of sweltering days, 53 more days for Austin and 52 more for Houston and McAllen.