Those who dispute the theory that global warming is producing more extreme weather events received a boost Wednesday with the release of a federal forecast indicating another milder-than-average hurricane season.
The National Oceanic and Atmospheric Administration Climate Prediction Center said in a statement that its 2015 Atlantic Hurricane Season Outlook shows a “below-normal hurricane season is most likely this year,” thanks in large part to the effect of the El Nino Southern Oscillation.
“The main climate factor expected to suppress this hurricane season is El Nino, which is now present and is expected to last through the hurricane season,” said the forecast summary.
Chip Knappenberger, assistant director of the Center for the Study of Science at the free-market Cato Institute, had this to say: “So much for claims that human-caused global warming is leading to ever-worsening extreme weather conditions.”
“In now the ninth year without a major hurricane making landfall in the U.S. (the longest such period on record), the global warming hysteria has largely been muted when it comes to Atlantic hurricanes,” Mr. Knappenberger said in an email.
The NOAA forecast calls for six to 11 tropical storms this year, including Tropical Storm Ana, which formed earlier this month. Three to six of those are expected to reach hurricane status with wind speeds of 74 miles per hour, while two may become major hurricanes at 111 miles per hour, said the summary.
The Union of Concerned Scientists and others have said that increased temperatures brought on by higher levels of carbon dioxide in the atmosphere would likely result in more intense hurricanes, typhoons and cyclones.
“Recent scientific evidence suggests a link between the destructive power (or intensity) of hurricanes and higher ocean temperatures, driven in large part by global warming,” said the organization in its report, “Hurricanes in a Warmer World: Exploring the potential causes of increase story intensity.”
“With rapid population growth in coastal regions placing many more people and structures in the path of these tropical cyclones there is a much greater risk of casualties, property damage, and financial hardship when these storms make landfall,” says the report.
Such arguments intensified after the destructive 2005 season that saw Hurricane Katrina and Hurricane Rita wreak devastation along the Gulf Coast.
Other scientists, often derided as “deniers” or “skeptics,” have challenged the connection between extreme weather events and carbon dioxide levels, saying there are too many other factors involved.
“The voices reached a crescendo in the mid-2000s after the destructive hurricane seasons of 2004 and 2005,” said Mr. Knappenberger. “But all along, NOAA hurricane forecasters/researchers have maintained that the Atlantic Multidecadal Oscillation was the culprit — not rising greenhouse gases.”
More recently, environmental groups have pointed to this year’s disastrous flooding in Texas and the Midwest as evidence of climate change.
In a Wednesday article in Scientific American headlined, “Climate Change May Have Souped Up Record-Breaking Texas Deluge,” Texas Tech researcher Katharine Hayhoe said that “climate change will affect us in the ways we’re already vulnerable to climate and weather today, and Texas is no exception.”
“When you have a warmer atmosphere, then you have the capability to hold more water vapor. When storms organize, there’s much more water you can wring out of the atmosphere compared to the past,” Brenda Ekwurzel, senior climate scientist at the Union of Concerned Scientists, told Climate Wire.
Myron Ebell, director of the Competitive Enterprise Institute’s Center for Energy and Environment, cautioned both sides against putting too much faith in the NOAA forecast.
“Predictions by NOAA’s Hurricane Center have proved to be wrong more often than not over the past several years, as have many others’ predictions,” Mr. Ebell said in an email.
No matter what happens, however, the result is likely to fuel the debate over global warming and extreme weather.
“If, despite NOAA’s prediction of a below-average Atlantic hurricane season, a major storm hits the U. S. and does a lot of damage, you can be sure that many alarmists will be quick to credit it to global warming — which by the way has been non-existent for the past 18 years,” Mr. Ebell said.
“NOAA is also predicting above-average hurricane activity in the Pacific,” he added. “That prediction may turn out to be wrong, too.”