4 June 2015
Update 9 PM June 14: NASA Climate expert Gavin Schmidt has a more technical explanation of the Karl paper today on Real Climate.
I’ve chatted before with Tom Karl about how difficult it is to measure the planet’s temperature. Karl,who is the head of the NOAA National Centers for Environmental Information (Formerly known as the Nat. Climate Data Center) is probably one of the top five experts on this anywhere, and today he published a major paper in Science that is already getting world-wide attention from the main stream press. There is good reason for it, because it confirms what many already suspected: There has been no slow down in the rise of global temperature. Chris Mooney has an excellent piece in the Washington Post about the paper today and the image above is from that piece.
1. The greenhouse gas levels are rising steadily and reaching new record levels.
2. Ocean heat content is continuing to rise, and the oceans are where most of the heat from the increasing greenhouse gases are going.
In short, if 5 things point in one direction and one thing says otherwise, you tend to doubt the outlier, and this was the case with the surface temperature record, which seemed to show the rise of temperature had slowed some. Remember though, that ANY measurement you make has error, and this is true for air temperature or water temperature. All of this data has to be adjusted to produce a graph like that above. Raw data is just that, raw data. Tom Karl points out in the interview with Chris Mooney that the sparse data from the Arctic makes is likely that the trend may be even higher, since the Arctic is warming far more rapidly than the mid-latitudes where most of the weather measurements are.
In short, what Karl has produced is now our best estimate of what the Earth’s temperature has been doing, and it’s not perfect, but until someone comes along and shows why their method is better,and then gets it published in a peer-reviewed science journal, this will stand. This paper is likely to be rather controversial among some because it takes away a popular talking point among some politicians. If they think it is wrong though, there is a simple way to fix that, just re-read this paragraph for the answer.