The science of climate change

In my early days of following Angry Bear, there was a climate change denialist troll whose handle was “CoRev.” Most of the stuff CoRev posted was standard denialist fare that had been debunked. At the time, one favorite denialist claim was the “hiatus,” a period between 2001 and 2014 during which warming seemed to “pause.” This, according to CoRev and like-minded denialists, was scientific evidence that climate change was a hoax. Part of the denialist schtick was to plot temperature data starting only a few years before 2001, exaggerating the apparent “pause.” In fact, if you plotted data starting in 1920, the pause appeared quite modest and a best-fit trend line starting in the 1970s supported the global warming hypothesis.

During this time, data emerged showing continued ocean temperatures increases and suggesting that the “missing” warming during the “hiatus” could be explained by heat storage in the world’s massive oceans.

Since 2014, two things happened: (1) the “hiatus” ended and global temperatures resumed their climb, and (2) CoRev disappeared. I don’t know whether CoRev changed its mind or simply bailed when the scientific evidence overwhelmed its denialist beliefs.

Talking Points Memo has an excellent piece on global warming data. Here’s a money quote:

“2015 became the warmest year on record, ending the hiatus, only to be surpassed by 2016, which remains the warmest calendar year so far in many records.

“A lot of year-to-year variability is associated with El Niño events. But it is more than that. Further analysis reveals that the Pacific decadal variability, sometimes referred to as the Pacific Decadal Oscillation or Inter-decadal Pacific Oscillation, resulted in changes in the amount of heat sequestered at various ocean depths.

“The Pacific Decadal Oscillation may be thought of as a northern-hemisphere version of the Inter-decadal Pacific Oscillation.

With the Pacific Decadal Oscillation, there were major changes in Pacific trade winds, sea-level pressure, sea level, rainfall and storm locations throughout the Pacific and Pacific-rim countries. These changes extended into the southern oceans and across the Arctic into the Atlantic.

“The effects are greatest in winter in each hemisphere. There is good but incomplete evidence that changes in winds alter ocean currents, ocean convection and overturning, resulting in changes in the amount of heat sequestered deep in the ocean during the negative phase of the Pacific Decadal Oscillation.”

I won’t abuse the TMP copyright by posting the whole thing. Read the rest here:

Global temperature rises in steps