Last August I posted a comment at this blog titled 'The Troposphere is Warming', in which I explained that, in accordance with global warming models, and according to a series of papers in the journal Science, the lower troposphere was warming.
Yesterday Vincent Grey sent me the following graph from the oh-so-not confidential IPCC report on the physical basis for global warming, as reviewed in a recent volume of Nature but not to be published until February next year, click here for a background briefing.
Vincent Grey interpretes this graph as showing no evidence of warming. As posted yesterday he has commented that:
"The satellite measurements show no temperature change between 1979 and 1997, but is then followed by a large sharp peak in 1998 because of the El Nino ocean event of that year, and since 2001 has shown a modest warm spell."
What is also interesting is that the two cool periods follow volcanic activity - El Chichon in 1982 and Pinatubo in 1991.
I wonder if any volcanos are likely to erupt in the next few years?
I find the graph fascinating.
It doesn't suggest to me a really close correlation between atmospheric carbon dioxide levels that have been showing a consistent rising trend over this time period, and the temperature in the lower troposphere?
There is an update on Mauna Loa, March 2006 was anomalously low compared to 2004 and 2005. April is average.
http://home.casema.nl/errenwijlens/co2/co2_200420052006_compare_01.gif
full thread on:
http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=899
Ian C,
Re tone: Don't worry about it! As for Hansen's lower than IPCC projection with scenario B1 and A2, I will go out on a limb by not trying to find out and instead just suggest he may be including some of his other mitigation measures such as soot and methane reductions that he often talks about.
As for higher predictions before I think Ian K is probably right that this came from the extremity of the scenarios not high sensitivities. This highlights your issue with identifying realistic scenarios, and I would argue that as the models agree more and more on climate's sensitivty to CO2, it becomes a higher priority to nail down the scenarios.
Ian Castles, I heartily agree that Ian Lowe’s statement compressed the timetable of climate change alarmingly. I confess that I don’t yet know sufficient of the history of climate change science for that period to excuse or contextualize it.
If I can however put it in the context of his book (which I think I started reading at the time but never finished. Perhaps I was naïve but he didn’t manage to galvanise me!) Now, pages 40-41 also include tables giving changes in temperatures for Australia and the world on the assumption of doubling of CO2. It seems to me that these are pretty much in line with currently estimated sensitivities.
So his error, I can only assume, stem from the emissions scenarios of the time, not from climate science. Reviewing this, now historical document, only tends to make me trust the models more! This seems to me to undercut Garth Paltridge’s assumption that the modelers have unconsciously built a bias into their models over recent years. The models may well be converging but I don’t see a convergence to scarier predictions.
But I really think that we shouldn’t be too concerned about these atmospherics! I wish I had figures at hand for the respective heat capacities of the oceans, landmasses, cryosphere and atmosphere (though of course their lapse rates, mixing ratios, etc would need to be taken into account). I think such comparisons would be salutary. Perhaps if we changed “global warming” to “global heating” and said where the heat was going rather than what are the temperature changes we would have a better feel for the problem.
BTW you said on the thread concerned with AR4 that “in 1987, Richard Morgenstern alleged there was 'an emerging concensus (sic) that the global warming could result in a rise in sea level on the order of two to seven feet (61-213 cm) by 2100', and cited multi-authored books that had appeared in 1983, 1985 and 1987.
Ian Lowe, at page 44 of Living in the Greenhouse, states that : “The favoured scenario quotes the most common 1987 view, which was that the best estimate of the increase was 80 cm, but that the possible error was 60 cm in either direction.” My view, for what it is worth, is that an “emerging consensus” is only a TREND towards that happy state of affairs and that Morgenstern could have been referring only to an emerging consensus as to the range of MAXIMUM sea level rises, rather than minimum-maximum ranges. I really do not think such an interpretation is as bizarre as it may seem to you.
My apologies Coby, my last comments addressed to you were cantankerous and go against the spirit of convergence (in views) which had been developing on this thread.
You are correct that achieving the B1 emissions profile requires 'dedicated effort', but by assumption that effort is directed to expanded R&D efforts to improve energy efficiency, agricultural productivity etc. in ways that will reduce emissions, NOT policies to reduce emissions that would have no justification other than climate policy.
On the issue of the response of temperatures to the B1 profile of emissions, Hansen et al (2005) come up with a much lower temperature increase this century than the IPCC TAR. Hansen et al are also much lower for A2 (increase of 2.7 deg. C in temperature). This is a puzzle and requires explanation.