Will Climate Change Debate Literally Heat Up in 2016?

Climate change denialists like Ted Cruz have insisted for years that global warming just stopped in 1998. The fact is, the earth has continued to get hotter: 2014 was the warmest year on record and the 10 hottest years are all after 1998, according to NASA.

There have been claims of a "hiatus" since 1998, but that's not quite true. The atmosphere has continued to warm, albeit somewhat more slowly than the remarkable increases over the previous 40 years. Scientists believed that more of the heat trapped by the CO2 in the atmosphere was being transferred into the oceans, since ocean temperatures have continued to increase faster than air temperatures, especially in the Arctic.

Now there is a report out that explains exactly why the atmospheric temperature increase slowed: the Pacific Decadal Oscillation (PDO) is a current in the northern Pacific Ocean. The PDO is similar to the El Niño Southern Oscillation which has a significant effect on weather in North America.

The PDO entered its "cooling phase" in 1999, causing ocean temperatures near the equator cool and while warming the subtropics to the north and south, sucking heat out of the atmosphere and into the ocean to a depth of 700 meters.

"Because the ocean is in contact with the atmosphere, there's heat exchange between the atmosphere and the surface ocean," [oceanographer Braddock Linsley] said. "It seems that about 90 percent of the heat that should be in the atmosphere right now with all that extra CO2 [humans have emitted since 1999] has gone into the ocean."

The problem?

In April 2014, the PDO moved to a positive phase [several years ahead of schedule]. Whether this is a temporary change remains to be seen. The signs so far have been ominous—2014 was the warmest year on record (ClimateWire, Jan. 9).

If it is permanent, "it is logical to suggest that the winds and ocean currents change accordingly and switch us into a new regime where heat is not buried so deeply, and we jump to the next level in global warming," [climatologist Kevin] Trenberth said.

If the PDO really has shifted, the summer of 2016 may be very hot and -- if Ted Cruz is the Republican candidate -- very embarrassing for climate change denialists.