Global Warming Hiatus?

During a December interview with NPR's Steve Inskeep, presidential candidate Ted Cruz turned the tables and asked the reporter a question.

"Let me ask you a question, Steve. Is there global warming, yes or no?"

"Absolutely, sure," Inskeep replied.

"Okay, you are incorrect," Cruz shot back. "Actually, the scientific evidence doesn’t support global warming. For the last 18 years, the satellite data — we have satellites that monitor the atmosphere — the satellites that actually measure the temperature showed no significant warming whatsoever."

"I’ll just note that NASA analyzes that same data differently," Inskeep said politely.

Cruz was repeating global warming denialists' most recent attack line. "A new record 'Pause': No global warming for 18 years 8 months!" proclaimed Climate Change Dispatch in September. Two months later, Climate Depot announced that the "pause" had reached 18 years, 9 months.

But Inskeep is right: Climate scientists at NASA do see continued warming since 1997. And they're not the only ones. Scientists from the National Oceanic and Atmospheric Administration and Britain's Climate Research Unit agree.

But you don't have to take their word for it. I've created a JavaScript chart to examine annual global mean temperature data from as far back as 1850 and calculate trend lines. When you choose a data source and starting and ending dates, it will plot the temperatures and calculate the correlation coefficient and linear regression.

You can select from among four data sources:

CRU: Climate Research Unit of the University of East Anglia [data file]

GISS: NASA Goddard Institute for Space Studies [data file]

NOAA: National Oceanic and Atmospheric Administration [data file]

BEST: Berkeley Earth Surface Temperatures [data file]

CRU and BEST data go back to 1850; GISS and NOAA to 1880. 

You can find these links and more at RealClimate's data sources page.

Select the full range, and you'll see a gradual upward trend. Select 1940 to 1970, and you'll see a slight decline. Select any start date through 2015, and you'll see a warming trend. You won't find a pause since 1997—or any year—no matter which data set you choose.