Tuesday, July 31, 2012

Climate change: BEST, Watts, and a glimmer of hope

This has been a busy few weeks in the climate controversy.

Back in 2010 the Berkeley Earth Surface Temperature (BEST) project was launched to improve and re-check the datasets of land-based temperature records. It was part funded by the Koch brothers, who fund climate skeptic work, and Anthony Watts, the main skeptic blogger, said on March 6th 2011

" I’m prepared to accept whatever result they produce, even if it proves my premise wrong." 
[Should that link ever go dead, let me know, and I will pop his whole post up here, because I have copied and stored it.]

Richard Muller, one of the leaders of BEST, was reputed to be a skeptic, but his conclusion is that the data converted him. He has posted in the New York Times that he has "concluded that global warming was real and that the prior estimates of the rate of warming were correct...Humans are almost entirely the cause".

Sadly, Watts has gone back on his word, and not accepted the BEST results. Instead, he has produced his own paper which looks in more detail at the "urban heat island effect" in US temperature stations. The heat island idea hinges on the point that as urban development changes the environment around temperature monitoring stations, there may be  erroneous warming biases in some of the readings. This is an old problem, which has been addressed here. Essentially, most urban stations are warmer than rural, but the trends are similar. Watts' new paper challenges this. He claims that the urban trends are roughly double the trends in rural stations.

One of his claims is that NOAA adjusted the data from the more accurate rural stations upwards to match the less accurate urban stations. However, I read Victor Venema  here : "the introduction of automatic weather stations (the transition from Liquid in Glass thermometers to the maximum–minimum temperature system) caused a temperature decrease in the raw data of 0.3 to 0.4 °C. This temperature jump has to be and was removed by homogenization."

The increase in the temperature trend is thus not due to adjustment of stations with a low trend to the ones with a strong trend, but due to the change in the way the temperature is measured, the transition from LiG to MMTS and also probably due to a change in the time of observation. Homogenization removes these artificial jumps and because they caused artificial cooler temperatures, the homogenized data shows a stronger trend. There is no evidence in Watts et al. that the good stations are adjusted to the bad ones. Watts et al. does not even study how homogenization algorithms function."

It is too early to get the full professional view on Watts' paper.  There is a discussion of it on the link given above, but it is not very systematic. I am not dismissing him absolutely - there is too much of that on both sides of the climate debate, and it is undeniable that if you change the environment of a reading station its readings are going to change. In the end, Watts is concentrating on a small detail. Even if  some land stations are unreliable, the ocean and satellite recordings still show that global temperature is rising unacceptably. 

As always with sceptics, I wish only too fervently that they were right, that things were not so bad as the science makes us think. As usual, however, they are making the error or composition: looking at one part of the system, and extrapolating from that one part to the condition of the whole system.

So that is roughly and briefly the state of play. My view is that the BEST study has done a lot to confirm the climate scientists' case and weaken the skeptics' case. This, added to the gradual perception by ordinary people that the weather is changing locally and generally, in a way that is consistent with the theory of climate change,  is going to bring about a sea change in public opinion. 

Already, despite the worst anti-wind propaganda efforts of the fossil fuel lobby, acceptance of wind turbines outnumbers rejection by two to one. As the reality dawns that the political right has a more slender grasp on what to do in a recession than your average gastropod has of quantum physics, it is quite possible that the people will look to an enhanced Green New Deal as the way out of the prolonged UK recession. 

In short, the supertanker of the state may be beginning to execute a slow but magnificent 180* turn away from stupidity to intelligence.

PS Here's the Skeptical Science take on Watts' paper.


weggis said...

Excuse me for being thick, but isn't the "Heat Island" effect in densely populated areas an argument that SUPPORTS the notion that human activity causes warming?

And since these "islands" aren't islands any more and are joined up into sprawling Metropoli covering whole bloody continents does that not undepin the AGW theory even more?

DocRichard said...

Hi Weggis

Apparently the effect of "direct heating" - the warmth we emit from our houses &c - is tiny compared to other influences like the sun, greenhouse gases &c. So tiny that it is just left out of the equation.

Nice to hear from you, hope you and Mrs W are well and enjoying the lovely weather brought to you by BP &c.