NOAA’s “new normal” climate report is anything but normal

By JEFF BERARDELLI – May 8, 2021

Just a quick glance at the new U.S. Climate Normals maps published by the National Oceanic and Atmospheric Administration (NOAA) on Tuesday is enough for most climate scientists to say, “I told you so.” And it’s not just because the maps show a warmer and wetter nation, as one would expect with global warming; it’s also the specific geographic pattern of those changes.

That’s because for decades climate scientists and their computer models have projected the regions that should expect the most warming, the most drying and the biggest increase in precipitation due to human-caused climate change. NOAA’s new maps are clear evidence that this impact is now being felt.

It doesn’t take a climate scientist to see the changes that have occurred. In the maps below, using NOAA data, Climate Central illustrates the warmer temperatures the U.S. has experienced. When comparing the latest “normals” to what used to be normal a century ago, the difference is clear — seen in red from coast to coast.


The map on the left depicts the updated climate “normals” compared to the normal temperatures of the early 20th century (1901-1930). In that time the U.S. has warmed an average of 1.7 degrees Fahrenheit. But the shades of the map show that not all areas are warming uniformly, with the darker red indicating temperature increases in some regions of 2 to 4 degrees Fahrenheit.

The map on the right is more muted in tone and shows the difference between recent 30-year averages, comparing the 1981-2010 normals to the new 1991-2020 normals. While the new normals are just 10 years removed from the earlier set, the changes are still significant. In that time the nation has warmed an average of half a degree Fahrenheit.

That may not sound like much, but small changes in the normals mean much larger changes in the extremes like heat waves, droughts, wildfires, floods and hurricanes. And hidden within the pattern of changes are interesting clues into how climate change will impact us now and into the future.

Defining the new normal

Every 10 years NOAA releases a new set of “climate normals” — what is considered normal, typical or average weather in a given location at a given time of year. To ensure that these normals are not subject to the ebb and flow of yearly weather, these averages are based on 30-year time periods to even out any short-term swings.

The new normal baseline is calculated from 8,700 weather stations operated by NOAA across the U.S. and its territories. The data includes information on temperature, precipitation and other weather variables.

So why update the normals every 10 years? First, it is required by the U.N.’s World Meteorological Organization. But on a practical note it is necessary to accurately reflect the state of the climate. These “normals” allow meteorologists, like myself, to compare the weather on any given day with what is historically expected, to give the public a gauge of how typical or extreme the weather is at any given moment.

“Keeping weather and climate data updated is important for the government officials and business owners who rely on it for decisions such as clothing, tourism, and construction companies, utilities, farmers, and city planners,” explains Bernadette Woods Placky, chief meteorologist at Climate Central. “But the fact that NOAA needs to keep pushing average temperature data higher is the sign of something bigger —the longer-term warming.”

But some climate scientists, like Michael Mann of Penn State, don’t love the system of reporting new normals. As he told The Associated Press, Mann prefers using a constant baseline because updating what is normal for present-day conditions obscures the long-term warming trend and makes the warming due to climate change seem less significant. “Adjusting normal every 10 years perverts the meaning of ‘normal’ and ‘normalizes’ away climate change,” said Mann.

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