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Climate Change Is Making Athens Hotter

The new climate normals are out, and it’s no surprise to see that Athens is getting hotter. What is surprising is the acceleration—how fast the city and state are warming.

Every 10 years, the National Oceanic and Atmospheric Administration recalculates a new set of these normals for the nation, states and individual weather stations across the United States, including Athens’ official recording station at Athens Ben-Epps Airport. The normals are a 30-year average—1991 through 2020 in the latest 2020 set—of such measures as the average daily high, low and overall temperatures by day, month and year. Normals also include averages for rain and snow.

Now the “normal” average annual temperature in Athens is 62.6 degrees, according to a database built by the High Plains Regional Climate Center at the University of Nebraska. That’s nearly a full degree hotter than the 2010 normal in Athens and 1.4 degrees hotter than the 1990 normal.

After rising sharply in the first decades of the 20th century, average temperatures actually declined in Athens, in Georgia and in the U.S. in the mid-20th century. It’s not clear why. The dip was once thought to be the effect of mid-century reforestation as millions of acres of used-up farmland and logged-over mountainsides and swamps regenerated as best they could. Calculations don’t support that theory, however, according to University of Georgia engineering professor David Stooksbury, the former climatologist for the state of Georgia.

Since that brief cooling, however, temperatures have been heating up at an accelerating pace in Athens, like the rest of the world. The 2000 normal average temperature (years 1971-2000) was .3 degrees higher than the 1990 normal. In 2010, normal went up another .3 degrees to 61.8, according to the Nebraska database. The latest 30-year normal bumps up the annual average again by almost a whole degree to 62.6, and most of that rise came just in the last decade. The average annual temperature for Athens edged up 0.1 degrees in the 1990s, jumped by another 0.6 degrees in the 2000s, then shot up 1.4 degrees to 63.7 in the 2010s. The thermometer at the airport topped 90 for a record 54 straight days in 2016, the warmest year on record for Athens.

Climate scientists are also seeing alarming acceleration in other measures of Induced climate change, such as the steady shrinkage of Arctic sea ice. The pace of climate change happening now looks a lot like what climate change scientists projected as worst-case scenarios not so long ago. “It does feel like it,” UGA agricultural climatologist Pam Knox said when asked if climate change is speeding up.

Athens is far from alone in rapidly rising temperatures. “In Florida, the last decade has just been off the charts,” Knox said.

Atlanta and other Georgia cities are also getting hotter, in patterns similar to Athens. Atlanta’s new normal average temperature is now 63.7 degrees, up 1.8 degrees since the 1990 normals. The 2010s in Hotlanta were 2.6 degrees warmer than the 1990 normal average.

Savannah, which also faces accelerating sea level rise from global warming, was 2.7 degrees hotter in the past decade than the 1990 normals, according to the numbers in the High Plains database. Models predict sea levels will rise by 10 feet or more, even if carbon emissions stopped immediately. Scientific debate is now more about whether that will happen in the next few decades or in the next couple of centuries.

In Athens and the other cities, winter temperatures have changed the most. The normal January temperature in Athens is now 2.7 degrees higher than in 1990, and February is up by 2.5 degrees. Over the past decade, Athens averaged 49.1 degrees in December, nearly 5 degrees higher than the 1990 December normal.

It’s not just the numbers that are changing now, but the very meaning of climate normals, said Knox, the former Wisconsin state climatologist and assistant state climatologist in Georgia. “Normals were designed with the expectation that the climate is stable,” she said. But with rapidly increasing warming, those normals are no longer the reliable tool they were for farmers and others when the first normals came out in 1931.

Athens’ average rainfall changed only slightly in the new normals; 48.95 inches per year, up from the 2010 normal of 46.33 inches. Over the past several decades, rainfall has been increasing significantly in the Northeast and declining sharply in the West, but averaging about the same in the Southeast. But there’s growing evidence that rainfall patterns, if not the averages, are changing as people pump more carbon into the atmosphere, Stooksbury said. Rain is coming in more intense bursts, with longer dry periods in between, like last month in Athens. Athens received 3.86 inches of rain on four days in early May, followed by 15 days of no rain at all. Georgia and the Southeast are also trending drier in the fall, according to NOAA statistics.

Meanwhile, the trend of rising temperatures is continuing. So far this year Athens has been nearly 2 degrees warmer than normal—2 degrees warmer than the new normal, that is.