Name: Anders Hedberg
Email: hedberg.anders@telia.com
Question:
I have been wondering about the causes of the global warming slowdown (the so called hiatus). According to one hypotheses it could be explained by lack of measure stations in the Arctic and according to another (M. England and S. Sherwood) it could be explained by absorbation of heat into the Pacific Ocean where trade winds are supposed to play an important role. Similar phenomenon are observed in the Atlantic ocean (M. Mann). Recently variations in El Nino are also discussed as an explanation for the ‘hiatus’ which to me seems to be a smilar kind of explanationas the one by England and Sherwood.
Do we have scientific support for both hypotheses or can one eliminate one?
If both hypotheses are given scientific support does that mean that the global warming are underestimated?
In order to give you the best answer I asked climate expert Ed Hawkins. Here is his answer:
There are several possible explanations for the hiatus, including Pacific (& Atlantic) Ocean heat uptake, missing Arctic data, small volcanic eruptions, a decline in solar activity, Asian aerosol pollution, as well as others. There is some support for all these hypotheses, and I think it is clear that they may all be involved to some degree. The implications for the future are not entirely clear, but there is little evidence that the climate projections are systematically underestimating future changes.