Bill Nye is a science guy. But, as the trope went for an old commercial, he isn’t a scientist, he just plays one on T.V. From time to time, Nye’s limited understanding of science can get him into trouble. One of those times was last week Nye talked about how global warming affected hurricanes.
On Radio Andy, a Sirius XM show, Nye told Dan Rather, “It’s the strength [of hurricanes] that is almost certainly associated with global warming.”
“Global warming and climate change are the same thing,” Nye said. “As the world gets warmer and there is more heat energy in the atmosphere, you expect storms to get stronger. You also expect ocean currents to not flow the way they always have and that will make some places cooler and some places warmer.”
“The more heat energy in the atmosphere strengthens the storms, Dan, that’s what you’d expect,” the science guy concluded.
Ryan Maue, a meteorologist whose Twitter bio also identifies him as a “think tanker” for the Cato Institute, took to Twitter to point out what should be obvious to a climate scientist, the fact that hurricanes draw their strength from the ocean not the atmosphere. “Bill Nye confuses the oceans with the atmosphere,” Maue tweeted, adding the hashtag, “#FakeScience.”
As most weather-watchers know, the ocean feeds hurricanes. They draw strength from warm tropical ocean water and grow while at sea. Once a hurricane makes landfall, the storm begins to weaken and dissipate, no matter how warm the atmosphere is.
That begs the question of whether global warming caused warmer ocean waters to feed the current crop of killer storms. Cliff Mass, a climate scientist at the University of Washington, says “no” on his blog.
“Hurricane Harvey developed in an environment in which temperatures were near normal in the atmosphere and slightly above normal in the Gulf,” Mass wrote. “The clear implication: global warming could not have contributed very much to the storm.”
“OK, let me go out on a limb,” Mass continues. “Let us assume that all of the .5 C warming of the Gulf was due to human-caused global warming. That NONE of it was natural. And that the air was warmed by the same amount. Using the scaling described above implies an increase of 3.5% in the extreme precipitation of this storm. So, for places that received 30 inches, perhaps 1 inch resulted from global warming. Not much. Immaterial regarding impacts or anything else.”
“The bottom line in this analysis is that both observations of the past decades and models looking forward to the future do not suggest that one can explain the heavy rains of Harvey by global warming, and folks that are suggesting it are poorly informing the public and decision makers,” Mass concludes.
NOAA’s Geophysical Fluid Dynamics Laboratory agrees in a statement on its website. “It is premature to conclude that human activities–and particularly greenhouse gas emissions that cause global warming–have already had a detectable impact on Atlantic hurricane or global tropical cyclone activity,” the agency points out.
NOAA’s statement does include a qualifier that climate change may cause worse storms in the future. “Anthropogenic warming by the end of the 21st century will likely cause tropical cyclones globally to be more intense on average (by 2 to 11% according to model projections for an IPCC A1B scenario),” the statement notes. “This change would imply an even larger percentage increase in the destructive potential per storm, assuming no reduction in storm size.”
Nye did make a second point that was more valid. “The problem in the Southeast United States and Mexico is that these hurricanes are very powerful,” the science guy said, “and, as I say all the time, they are very expensive. We are all going to pay for Harvey. We are all going to pay for Irma one way or the other.”
Mass agrees here, saying, “What the media SHOULD be discussing is the lack of resilience of our infrastructure to CURRENT extreme weather. Houston has had multiple floods the past few years and poor planning is a major issue. When you put massive amounts of concrete and buildings over an historical swamp, water problems will occur if drainage and water storage is not engineered from the start.”
Hurricane Harvey, a category three storm, was not the strongest hurricane on record. The biggest problem was the that storm stalled over Houston rather than moving through quickly. This caused Houston’s Depression-era drainage system to overload. The area’s rapid growth and lack of planning have contributed to the problem.
Hurricanes Harvey and Irma were very damaging, but there is no evidence that they were the result of climate change. In fact, the storms were weaker and less damaging that the category four hurricane that killed 12,000 people in Galveston, Texas. If you don’t remember that one, it is because it happened in 1900, long before the advent of global warming.