Ignore those shivers over this week’s single-digit temperatures. NASA and the National Oceanic Atmospheric Administration said Wednesday that 2015 was the hottest year in 136 years of record keeping.

The 2015 average temperature was 58.62 degrees Fahrenheit, 0.29 degrees higher than 2014’s, NOAA said. Scientists put the blame on the El Nino ocean-atmosphere interaction and human-caused global warming.

The announcement came two days after the journal Nature Climate Change published a study showing that the amount of man-made heat energy absorbed by the oceans has doubled since 1997. Both revelations are more evidence that humans must pay more attention to environmental changes confronting the planet.

Utilizing data stretching from the British research ship Challenger in the 1870s to statistics from the 1990s, ocean researchers reported that the Earth’s waters absorbed 150 zettajoules of energy from 1865 to 1997. But it took only 18 more years for the oceans to soak up another 150 zettajoules. This is both astounding and disturbing.

Because the subject of climate change is so politically contested, independent studies like those reported this week continue to be important. The ocean research was conducted by the Lawrence Livermore National Lab, Penn State University and other reputable institutions.

Determining how human activity has raised the temperatures of the oceans and the air requires the constant gathering of evidence from many sources. These reports, of course, will be followed by other data. The latest findings are two more independent signs that climate change deniers need to stop and smell the science.

(c)2016 Pittsburgh Post-Gazette

Visit the Pittsburgh Post-Gazette at www.post-gazette.com

Distributed by Tribune Content Agency, LLC.