Climate sensitive to solar cycles and CO2 – a note from Luke

For the first time a globally coherent solar cycle response to the surface temperature has been established. Charles Camp and Ka Kit Tung report in Geophysical Research Letters (DOI: 10.1029/2007GL030207) that global temperatures oscillated by 0.2C during the high and low points of the cycle. The research uses satellite solar radiation and surface temperature gridded data from the last 50 years over four and a half solar cycles.

The authors’ analysis also shows greater warming in the polar regions in common with climate model predictions.

In a yet unpublished but submitted paper, Tung and Camp undertake another analysis, without resorting to climate models, that give a climate sensitivity for doubling CO2 between 2.3 and 4.1C as a 95% confidence interval.

The authors add that due to ocean lag effects these numbers are likely to be underestimates.

The work, bound to be controversial, puts more complexity back into the game coming hot on the heels of the Smith et al internal variability paper.

But reader beware, these papers are serious science not rambling quasi-political anecdotes.

2 Responses to Climate sensitive to solar cycles and CO2 – a note from Luke

  1. Paul Biggs August 29, 2007 at 10:20 pm #

    If my memory serves me correctly, Lockwood and Frohlich (2007) stated that the surface temperature doesn’t respond to the 11-year solar cycle, although the Camp and Tung paper was published after L & F.

    Camp and Tung seem 95% conifident they can’t estimate climate sensitivity within a factor of around 2!

  2. SJT September 2, 2007 at 12:01 pm #

    Means we had better extra careful with the risk then.

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