A new Global Warming Policy Foundation report from retired Oxford physicist Ralph Alexander supports the Intergovernmental Panel on Climate Change’s conclusion there is limited scientific evidence linking human caused climate change to increases in extreme weather. Alexander’s conclusions are also confirmed by recent documents produced by Heartland Senior Fellow Anthony Watts on the website “Climate at a Glance.”
Alexander’s paper begins by remarking, “[t]he purported link between extreme weather and global warming has captured the public imagination and attention of the mainstream media far more than any of the other claims made by the narrative of human-caused climate change.”
This is surprising because data and analyses from the Intergovernmental Panel on Climate Change (IPCC)—the UN body that climate alarmists in academic, political, and media circles continually cite as the authoritative source of information on climate change—confirm that “if there is any trend at all in extreme weather, it’s downward rather than upward. Our most extreme weather, be it heat wave, drought, flood, hurricane or tornado, occurred many years ago, long before the carbon dioxide level in the atmosphere began to climb at its present rate,” writes Alexander.
“Recent atmospheric heat waves in western Europe,” writes Alexander, “pale in comparison with the soaring temperatures of the 1930s, a period when three of the seven continents and 32 of the 50 US states set all-time high temperature records, which still stand today.”
Nor has IPCC discerned or identified any long-term trend in drought patterns, either in the United States or globally. And even though rainfall has modestly increased in recent years, there is no evidence floods are becoming more frequent or severe. Alexander notes, many recent flood events can be traced almost entirely to land-use changes, including channelization, deforestation, destruction of wetlands, and the building of dams.
“Climate at a Glance: Floods” confirms Alexander’s assessment, citing data showing there has been no evidence of increasing flooding frequency or severity in the United States or elsewhere over the past century and a half. Indeed, IPCC writes it has “low confidence” in any climate change impact regarding the frequency or severity of floods, going so far as to state it has “low confidence” in even the “sign” of any changes. In other words, it is just as likely that climate change is making floods less frequent and less severe.
On top of that, a 2017 study on the climate impact of flooding for the United States and Europe, published in the Journal of Hydrology, found, “The number of significant trends was about the number expected due to chance alone,” and “Changes in the frequency of major floods are dominated by multidecadal variability.”
Alexander notes hurricanes and tropical cyclones actually show a decreasing trend around the globe, with the frequency of land-falling hurricanes of any strength (Categories 1 through 5) remaining unchanged for at least 50 years. While the frequency of major North Atlantic hurricanes, which are the most studied, has increased during the past 20 years, the current heightened activity level is merely comparable to the 1950s and 1960s—a period when the earth was cooling, not warming.