Iowa getting warmer, wetter
February 17, 2017


To the editor:

It is the rate of climate change (faster than expected by scientists) that should concern farmers, though Jerry Crew's no tillage and adopting cover crops are part of the necessary adaptation (Feb. 3 letter to then editor).

Climate deniers argue that "some of the worst weather has happened in the distant past." I use standard weather data from Iowa's climatologist for 144 years to show extremes clustered after 2006.

For 2016, Iowa's Total Average Precipitation (TAP) of 38.97 inches was recorded as the 19th wettest. However, it was less than Iowa's TAP from 2010, 2008, 2007, 2015, 2009 and 2014.

Seven of the 19 wettest years for all of Iowa were in the last 10 years, only 12 were from the prior 124 years. If precipitation amounts were random as Crew seems to suggest, such a wet year would only happen every seven years or so.

Iowa's actual and historical Annual Average Temperature (AAT) for all of 2003 was 47.8 degrees F. By 2016, the actual AAT was 50.6 degrees F., and the historical AAT was 48.1 degrees F. Nine of the interim 13 years had been hotter than 2003's AAT. (2012 was the 4th warmest year in 140 years; 2016 the 5th warmest; and 2006 the 14th warmest.) Lately, Iowa is getting wetter and warmer.

The rate of climate change could become even faster or more varied. The half life of CO 2 in the atmosphere is around 100 years causing total accumulations to increase even when annual emissions decrease. Hot air holds more water vapor than cold air. Feedback loops from melting permafrost or dark oceans replacing glaciers amplify impacts, as may other factors.

Farmers should be asking how best to reduce their carbon footprints to slow down climate change. Jerry Crew recognizes that no-till and cover crops create carbon sinks, keeping CO 2 in the ground.

I hope climate change scientists can discover more ways to prevent, or at least slow down, extreme weather disasters so our planet can recover.

Liz Gilbert

Iowa Falls


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