Michael Bastasch reports for the Daily Caller about an interesting discovery from noted climate scientist Roy Spencer.

When Dr. Roy Spencer looked up summer temperature data for the U.S. Corn Belt, it showed no warming trend for over a century. But that was before temperatures were “adjusted” by National Oceanic and Atmospheric Administration climate scientists — now the same data shows a significant warming trend.

Spencer, a climate scientist at the University of Alabama in Huntsville, said that the National Climatic Data Center made large adjustments to past summer temperatures for the U.S. Corn Belt, lowering past temperatures to make them cooler. Adjusting past temperatures downward creates a significant warming trend in the data that didn’t exist before.

“I was updating a U.S. Corn Belt summer temperature and precipitation dataset from the NCDC website, and all of a sudden the no-warming-trend-since-1900 turned into a significant warming trend,” Spencer wrote on his blog, adding that NCDC’s “adjustments” made the warming trend for the region increase from just 0.2 degrees fahrenheit per century to 0.6 degrees per century.

NCDC temperature data downloaded by Spencer in March 2014 looked quite different from data he downloaded this month. That’s because NCDC constantly adjusts its data to correct for errors, but critics have said these adjustments seem to always increase the warming trend for the U.S. or globally.