Study Finds Climate Change Means Less Drought in US

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By Paul Homewood

More one-sided reporting from the Capital Weather Gang!

When it rains, it pours.

A paper published Tuesday in the journal Geophysical Research Letters finds that it’s raining harder in most of the United States. The study, written by researchers at Northwestern University, tied the results to climate change and to warmer air’s ability to hold more water.

The findings echo the fundamental laws of physics and thermodynamics, as well as the evidence from decades of research, and highlight the real-time effect that humans are having on the weather and climate.

The research offers confirmation of what atmospheric scientists have been warning of for years: a warmer world is, on balance, a wetter world. And as global temperatures continue to rise, an uptick in precipitation extremes is expected.

The study reports “consistent shifts from lower to higher daily precipitation intensities, particularly in the central and eastern United States.” The authors compared rainfall over two periods — 1951 to 1980 and 1991 to 2020 — to see how patterns evolved.

In the study, the authors examined daily data from more than 1,700 weather stations distributed in the Lower 48. Each had to have a continuous record dating back to at least 1951 to be included in the study.

In the eastern United States, the researchers observed a 4.5 to 5.7 percent increase in average daily rainfall on days when it rained. That does not say there are more days with rain, or more rain overall.

Despite strong trends in the central and eastern United States, the authors noted that there were a few places where rainfall did not appear to be growing more intense. The paper does detail “mixed signals in the western U.S.,” but for reasons the authors are still trying to identify.

“That [trend] didn’t hold true for the western U.S.,” said Harp, especially in the Pacific Northwest. He explained that changes in the overall placement of weather systems are “suppressing” any tendency for heavier precipitation in the West. A slight change in the location at which high and low pressure systems are anchored can have an enormous bearing on steering currents, and subsequently on how much precipitation falls in a given location.

https://www.washingtonpost.com/climate-environment/2022/10/11/rain-increasing-climate-change-us/

As Steve Milloy points out, the paper itself makes no claim that climate change is responsible. It may just be all due to natural cycles.

But regardless of the cause, let’s consider what “more intense rainfall” really means. (The calculation used is average rainfall per rain day)

The Washington Post would like us all to think that more rainfall is some sort of disaster, backed up by photos of floods. In fact that extra rainfall has arguably been wholly beneficial, as it has served to prevent the sort of severe droughts, which used to be common place in much of the US.

Below are the annual rainfall trends for the four NWS regions, as mapped underneath:

Climate at a Glance | National Centers for Environmental Information (NCEI) (noaa.gov) 

As is blatantly clear, severe droughts were a common feature of the 1951-80 period in the first three regions. Droughts like these are now much less common.

In the West Region however, there has been little overall trend, which explains why the authors also could not find evidence of any trends in rainfall intensity. This factor alone should make anybody suspicious about the “global warming” explanation of heavier rain in the other regions.

Long lasting droughts can be far more damaging, both economically and in human terms, than short lived spells of heavy rainfall. And there is absolutely no doubt at all that the farmers who suffered in the dustbowl years, or the arguably greater droughts in the 1950s, would have the heavier rainfall we have nowadays.

The Washington Post headline should really have read:

“Study finds climate change is bringing less drought to U.S”

via NOT A LOT OF PEOPLE KNOW THAT

October 15, 2022

Study Finds Climate Change Means Less Drought In US | NOT A LOT OF PEOPLE KNOW THAT (wordpress.com)