Matt Ridley has written an opinion piece for The Times (not the New York Times, the other one) which is a response to his critics, specifically, to those who openly disagree with him about climate change. Ridley’s commentary is jaw dropping, and for most of you, those who are not of Royal Blood and highly privileged, it is more than a little squirm-inducing. But, putting that aside, Ridley makes a number of assertions, two of which (*) I’d like to address. Other problems with Ridley’s approach have been addressed here, by Dana Nuccitelli.
Spoiler alert, he is wrong on both counts.
First, to summarize his arguments, I paraphrase of his commentary in The Times (which is behind a paywall), in bullet point form:
- Since so many people disagree with me, I am probably right.
- I think global warming is real, and mostly man-made.
- I think global warming is not dangerous.
- I think global warming is slow and erratic*, AND will continued to be*.
- That global warming has been slow lately conforms with my lukewarm hypothesis.
- I annoy people.
- I have been called a lot of names.
- My detractors are mainly public employees including scientists and politicians.
- I have lost opportunities because people conspire against me.
- I do other things than write about climate change.
- People do not attack my arguments, they attack my motives. For example, I make money off of coal.
- I really prefer natural gas to coal.
- I have been offered, many times, opportunities to install clean energy technology on my vast land holdings. I have refused every time.
- I used to think climate change is serious, but since it seems to have slowed down, I no longer think so.
- Climate change models are wrong.
- The hockey stick graph has been discredited. (I quickly add that the hockey stick graph has been confirmed again and again. See this. A version of the hockey stick graph is the image at the top of this post.)
- Steve McIntyre and Ross McKitrick have it right. (They don’t; see the links.) The vast majority of the other climate scientists have it wrong.
- Climate change is not settled science. (There is, of course, a scientific consensus on climate change.)
- The IPCC agrees with me.
- Policies to combat climate change are ineffective, expensive, harmful to the poor, and bad for the environment.
- No one had ever effectively addressed my doubts.
- Bob Ward is a poopyface.
Of these assertions, I want to address only two (starred); Ridley has said that global warming has slowed down, and he has said that this slowness will continue in the future. These are both reasonable hypotheses at first glance, and testable. So let us test them. But before we do, I want to point out that they are not really reasonable hypotheses, because the physics are pretty solid on climate change. A real long term slow down in warming would be unexpected, astounding even, given what we know about how the atmosphere works. That alone does not make the ideas impossible, necessarily, but it certainly gives Ridley’s hypotheses a rather steep incline.
First, has global warming slowed down? If it has, Ridley may be on to something (but maybe not). If it has not, then this hypothesis is falsified.
There are several lines of evidence to suggest that global warming has not slowed down. First, we need to acknowledge that “warming” as the term is often used means changes in estimated global surface temperatures based only on measurement of the air near ground level, combined with sea surface temperatures. An excellent primer on how this is done can be found here. Keep that in mind.
Some have suggested that there has been a recent slowdown in global warming, as per this particular measurement. The first thing you need to know is that there are frequent slowdowns in warming in this data, as well as frequent speedups. One way to characterize this is to have a look at the famous Escalator Graph produced some time ago by by Dana Nuccitelli and recently updated.
Now that we understand that the squiggle representing surface temperature … well, squiggles up and down … we can have a longer term look at warming and see if an estimate of the rate of warming for recent years shows a slowdown. Climate Scientist Gavin Schmidt recently tweeted this graphic addressing this very question:
Notice that the trend does in fact drop slightly in upward slope in recent years. Ever. So. Slightly. But, in the end, 2014, which turned out to be the hottest year of the instrumental record so far, is dead on the long term prediction of warming. In other words, rather than warming slowing below the predicted level, it has nearly maintained the predicted level, thus falsifying Ridley’s hypothesis. Don’t expect 2015 do be a big drop in temperature. It is way too early to say anything close to definitive about the year we just started. But, January has been warm and we are expecting El Nino conditions to add heat to the atmosphere this year, so we might expect 2015 to be like 2014, or may be even warmer.
But, yes, there may be a slowing of surface temperature increase, but that is only part of the story. The vast majority of the heat that is added to (or subtracted from) the Earth goes into and out of the deeper ocean, not the atmosphere or sea surface. (See above graphic.) This means that the surface temperatures are a bit like the tail of the dog, where the dog itself is the sea. I wrote about this here. Meanwhile, there is strong evidence that the top 2000 meters or so of the oceans is indeed taking in the extra heat that helps account for a minor slowdown in warming. Here is a link to a recent paper on this, by John Abraham, John Fasullo and Me. And here’s a graph from that paper:
So, Ridley’s first hypothesis, that warming is slow, is falsified.
To the extent that there is some slowing in recent years, it is generally thought that this is a combination of the ocean taking in extra heat, some slowing of warming due to dust put into the atmosphere by a higher than usual amount of volcanic activity (from smaller volcanoes, the ones you don’t really notice unless you live near them), and a current decline in the energy provided by the sun (not to worry, that goes up and down on a regular basis). In that order, probably.
Let me add that even if warming was slower than some preconceived rate, that does not mean that it is not a problem. First, even a slowed down rate of warming suggested by Ridley and others is very fast by long term geological standards, too high to be safe. Second, certain long term effects of warming, such as melting polar ice sheets and causing massive sea level rise, may simply arrive later. But they will still arrive.
Ridley’s second hypothesis, that global warming will be slow in the future, is not testable at this time. The fact that his second hypothesis is based on the first, that future slowness is assumed because of (non-existing) present day slowness, seems to be obviated. But, we can let the hypothesis stand as proposed and untested, if for no other reason than to mitigate Matt Ridley’s whinge. Then, in a few years, we can test it. Ridley is, essentially, predicting that over the next decade or so far more years will fall below a regression line based on recent decades, with fewer and fewer years falling above the line as time marches on. In a few years, let’s check back.
Meanwhile, let’s be sensible and smart and do something about global warming, because it is real. For his part, I hope Matt Ridley stops mining coal out of his own land and allows those other folks to put up a windmill or two. That would be royal.