Depressed by the gloomy alarm of Ross Garnaut’s revised climate review?
“Global temperatures continue to rise around the midpoints of the range of the projections of the Intergovernmental Panel on Climate Change (IPCC) … It is an awful reality that no major developments inthe science hold out realistic hope that the judgements of the 2008 Review erred in the direction of overestimating the risks of climate change.” Extract from Garnaut Review, “Update Paper 5: The Science of Clmate Change”
Well… Don’t Panic!™ The sky is not about to fall-in no matter how much Dr Garnaut growls. In fact, the what you find by looking at the data rather than at a model of the data is pretty encouraging.
Here’s an updated version of a picture that is a favorite of mine. It shows a graphic from a 2006 paper by NASA’s James Hansen et. al. —the alarmist-in-chief and his crew. This paper is itself an updated version of the paper [warning: 5 mb] that started the political panic back in 1988. Note, especially, “Scenario C”—a climate modelling projection later adopted by the UN IPCC—that describes the outlook for the emissions trajectory that Hansen and the IPCC considered least-likely: emissions held stable at year-2000 levels. That is, the “no warming” base-case.
Over the top of the Hansen graph I’ve drawn a dot representing NASA-GISS’ latest estimate of global temperature anomalies for February, 2011: 0.44°C. You can see that this observed temperature falls below the projections made for even “Scenario C”. It’s been that way for a while, now, and to me it looks like staying that way for a while yet.
Here is one reason for my optimism: my plot of NOAA’s latest land-temperature anomalies (the February down-turn is not yet reflected in this data). You can easily see the un-alarming trend over the past two decades for yourself.
By the way, the “Eemian” period referenced in Hansen’s graphic was the last inter-glacial period, about 125,000 years ago. It was a time when temperatures were stable but some 1 – 2°C higher than they are today. We are now probably coming to the end of the current inter-glacial period on earth (glaciation has been occurring every 100k years-or-so associated with the movement of the solar system through the galaxy). So it’s a reasonable speculation—briefly canvassed in the Hansen paper—that we’re experiencing a slow global warming toward the same levels as occurred during the last inter-glacial.
But that speculation was dismissed by Dr Hansen on account of “the magnitude of feedbacks under BAU [‘business-as-usual’] warming, which is far outside the range of interglacial temperatures”. He argued that man’s economic activities (BAU) will result in large greenhouse emissions that will drive big positive climate feedbacks, condemning the earth to much higjher levels of warming than in the Eemian period.
We’ve been waiting to see evidence of Hansen’s “feedback” for 22 years now, with no evidence stronger than the imaginary traces of the climate models.