Climate Denialists Use 1930s Heat As A Red Herring

 It seems like every time somebody mentions climate change on social media, some clown will interject "but the 1930s!"

From Berkeley Earth: Maps show how far
above or below the 20th century average
summertime high temperatures were in the
1930s (top) and the period 2013-2022
(bottom). So no, the world was NOT hotter
in the 1930s, despite extreme heat
in central North America. 

That's because many of the worst heat waves in U.S. history happened then. In 14 states, the  hottest temperatures on record came in July, 1936 and those records still stand.  

Many cities in the Great Plains, Midwest and Middle Atlantic States still have all time record highs occurring in the 1930s. 

The denialists are absolutely correct that the heat in the middle of North America as off the charts in the 1930s. 

What the forget to note is most of the rest of the world was relatively cool. They kinda take the "globe" out of global warming. 

They also don't talk about the reasons why those summers were so hot.  Farming practices contributed to the heat. Also, there are natural cycles that will make certain place especially hot or cold, and this will happen with or without climate change.  

The denialists also forget about the fact that there were intensely, record cold winters in the 1930s, and the winter cold was much more widespread than the summer heat. 

DUST BOWL HEAT REASONS

The 1930s brought the Great Depression, which was bad enough, and the famous "Dust Bowl" years. 

The University of Nebraska National Drought Mitigation Center tells us what led to the heat and the Dust Bowl:

"'Boosters of the region, hoping to  promote settlement, put forth glowing but inaccurate accounts of the Great Plains' agricultural potential. In addition to this inaccurate information, most settlers had little moment and few other assets, and their farming experience was based on conditions in the more humid eastern United States, so the crops and cultivation practices they chose were often not suitable for the Great Plains. 

But the earliest settlements occurred during a wet cycle, and the first crops flourished, so settlers were encouraged to continue prices that would later have to be abandoned."

Then, as Yale Climate Connections explains, natural cycles with roots in far away oceans contributed to an intense Great Plains drought from about 1928 to around 1942. 

This cycle encouraged the familiar "heat dome" we so frequently talk about nowadays to set up shop over the middle of North America.  

Those bad agricultural practices created vast expanses of bare soil that absorbed the sun's heat to maximize the sun's heating. That made temperatures soar to unprecedented levels. Those record highs stand to this day. 

The heat was so intense it was able to spread into south-central Canada and the Mid-Atlantic States. But much of the world avoided this disaster, partly because climate change hadn't kicked in yet. 

COOL ELSEWHERE   

Vermont was much like the rest of the world in the 1930s. We sat out the 1930s dust bowl heat. July, 1936 was cooler than normal. Burlington that month only made it to 90 twice, and reached 80 or above just eight days during the entire month. 

July, 1934 was also extremely hot in the Great Plains and other parts of the nation. Not so here in Vermont. July that year in Burlington had close to average temperatures, but the hottest it got all month was one day of 90 degree temperatures. 

Berkeley Earth did a comparison showing how average daily maximum temperatures worldwide during the 1930s compare to "normal" base on 1951-1980.

The maps show central North America was indeed very hot. Much of Europe was on the warm side, too. But vast areas of the world were a little on the cool side during Depression-era summer afternoons. 

If you look at the 1930s based on the whole year, not just the summer, you see that central North America was only barely warmer than average. Intensely cold winters during the 1930s offset those hot summers. 

Meanwhile, the most recent ten year period cited in the data  from 2013 to 2022 shows almost the entire world was warmer than in the 1930s. In many cases much warmer. 

 That climate denial trolls keep citing the 1930s heat in the Great Plains is a classic example of "cherry picking."

As Andrew Kessler and Zeke Hausfather wrote in The Climate Brink last year:

"Cherry picking is a tactic where someone selectively chooses a small portion of a data set that contradicts the conclusion drawn from the entire dataset. This aims to mislead the audience by presenting a distorted picture of reality, leading them to question established facts."

In other words, they're practicing the art of Kellyanne Conway's famous "alternative facts." Another word for all this is gaslighting.

Always look out for that. 

The bottom line: No, the world wasn't hotter in the 1930s. Turns out that's a pants on fire lie.