A Tale of Two Predictions

Real Climate has done two posts recently that I thought would be served well by their juxtaposition. The first one highlights an early projection of global mean temperatures made by Jim Hansen in 1981.

The abstract for that paper contains this choice quote:

It is shown that the anthropogenic carbon dioxide warming should emerge from the noise level of natural climate variability by the end of the century, and there is a high probability of warming in the 1980's.

These are both things that have in fact happened. I think it is safe to call this a very successful early prediction of anthropogenic climate change. Also in the abstract we have this:

Potential effects on climate in the 21st century include the creation of drought-prone regions in North America and central Asia as part of a shifting of climatic zones, erosion of the West Antarctic ice sheet with a consequent worldwide rise in sea level, and opening of the fabled Northwest Passage.

The drought in Texas certainly fits this description, as does the opening of the no longer fabled but now geopolitically contentious Northwest Passage.

The second post is about arctic sea ice. You can go have a read for RC's usual interesting and informative exposition, but for my purpose the topic is summed up very well by this graph from the 2009 Copenhagen Climate Change summit:
(h/t SkS)

I think it is valuable to place that graph next to this RC modified graph from Hansen et al 1981:

So the next time some one arguing in blog comments somewhere about unverified or unfulfilled global warming predictions pops up, put these two graphs in front of them. The arctic sea ice image is also an excellent reminder that uncertainty about the future just is not anyone's friend!

More like this

*note Global Warming is VERY BAD and title is sarcasm. Flashback to 1992, it's early in the morning and a decrepit high school teacher stands before a class discussing the finer points of history. In the back row sits a smart ass, me, not listening and telling himself why should a future marine…
Each of these graphs from the IPCC policy summary shows the global surface temperature relative to a 1961-1990 arbitrary baseline. The upper graph shows the annual average, and thus captures a sense of variation reflecting a wide range of causes, but with a general trend from the early 20th…
OK. I've read Hansen's new paper, which has been submitted to Environmental Research Letters, but not published. It's basically a review of existing, well-established science followed some personal opinion on the responsibility of scientists to express themselves, so I doubt it will be edited much…
The headline for this post is stolen verbatim from a section headline in a paper on climate change just published in Philosophical Transactions of the Royal Society A. It's yet another depressing read by NASA's Jim Hansen and five co-authors from the University of California, Santa Barbara and the…