COLLEGE STATION – There’s very good evidence the same factors contributing to the drought – the El Niño-La Niña cycle — have temporarily stalled global warming, according to a Texas A&M University climatologist.
During the last two decades of the 20th century, climatologists recorded a rapid rise in average temperatures. But in the last decade the rise has leveled off, said Dr. John Nielsen-Gammon, Texas State Climatologist, College Station.
“Global temperatures have been relatively flat for the past several years, Nielsen-Gammon said. “Some people use that information to try to imply that global warming has stopped. But it turns out that the factors causing global warming are still there, it’s just that the El Niño-La Niña cycle has temporarily trended cooler and has partially masked the warming.”
Nielsen-Gammon compared a strong La Niña’s effect on atmospheric temperatures to that of leaving a refrigerator door open.
“In the tropical Pacific, there’s actually fairly cold water just below the surface,” he said. “With a La Niña event, that cold water is drawn all the way up to the surface, and interacts with the atmosphere and causes it to be cooler. If you leave the refrigerator door open, the room will be a little cooler.”
But this is a temporary effect rather than a long-term effect, as are the ever- increasing concentrations of greenhouse gases during the last 50 years, he said.
“If my forecast is correct, and there’s no La Niña to hide the underlying warming trend, global surface temperatures are likely to increase and set a new record this year.”
For the short term, the next four or five years, farmers and ranchers might hope global warming does pick back up this year, Nielsen-Gammon said.
“On the short term, the same oceanic factors that cause global temperatures to go up temporarily also tends to cause rainfall in the Southern U.S. to go up temporarily,” he said.
More information on the current Texas drought and wildfire alerts can be found on the AgriLife Extension Agricultural Drought Task Force website at http://agrilife.tamu.edu/drought/ .
AgriLife Extension district reporters compiled the following summaries for March 11-18:
The 12 Texas A&M AgriLife Extension Service Districts
Central: Producers began planting corn for silage and forage sorghum. Winter wheat was providing quality grazing. Coastal Bermuda grass came out of dormancy, and oats were heading out. Livestock producers cut back feeding hay as pastures greened up. Bluebonnets were already flowering. Livestock were in good condition.