This is my sixth post responding to writer (and new Lord) Matthew Ridley’s recent essay for the GWPF (found here: Ridley-Lukewarmer-Ten-Tests). His thesis is there are ten points that need to be answered before he will be convinced that current policy regarding climate change makes any sense at all. If you look below, you’ll see my responses to the first five of his tests.
His sixth test is this: “Given that we know that the warming so far has increased global vegetation cover, increased precipitation, lengthened growing seasons, cause minimal ecological change and had no impact on extreme weather events, I need persuading that future warming will be fast enough and large enough to do net harm rather than net good. Unless water-vapour-supercharged, the models suggest a high probability of temperatures changing less than 2C, which almost everybody agrees will do net good.”
Once again, as I also think temperature rises will be on the rough order of 2C, some might be surprised that I even bother responding to this point.
However, I believe that a temperature rise of 2C will cause net harm and I find very little evidence that many, let alone almost everybody, agree that such a rise would do net good.
Stay with me here. Global warming is of course an accounting fiction–what warming we are fighting about is an average increase, with some regions warming much more and some much less than the average 0.8C the world has experienced over the past century. Scientists believe that that variability will not change.
The IPCC has written that over the first two decades of this century continued warming will bring benefits to regions in the
middle (Update: non-tropical) latitudes and that those benefits may outweigh the losses experienced by other regions. So that there’s a net economic gain in the first two decades can reasonably be argued.
However, the regions experiencing the gains are richer than those experiencing the pain, so I would argue that the net benefit to humanity is not equivalent to the economic benefits which I do not dispute.
Moreover, although models cannot provide resolution enough to identify which regions will be most affected by future warming, some scientists have postulated that wet areas will get much wetter and dry areas much drier–this would again disproportionately impact the poorer parts of the planet.
We already see that the Arctic has warmed much faster than the rest of the world and the dramatic loss of summer ice cover over the Arctic Ocean worries me. It may have had an impact on the trajectory taken by the storm/hurricane Sandy, as the increased open water may have blocked its more normal path and steered it onto the Jersey shore. I’m not saying that that would become the norm, but it only has to become slightly more frequent to have real consequences.
A much warmer Arctic might have other consequences as well, changing wind patterns and weather across much of the Northern Hemisphere. Although these changes would probably not be crippling, they would require adaptation to the new regime.
My biggest concern, apart from the worsened immiseration of poor people on the receiving end of rainier rainy season and droughtier droughts (I’m not sure if droughtier is even a real word, let alone a technical term) is whether there would be an impact on large areas of peat. If they warm enough they will release their stored methane, which would contribute additional greenhouse gases.
The IPCC believes that the net effects of warming will turn negative after two decades, long before we achieve 2C of warming. Of course, their assumption is that warming would continue to possibly 3C, and we part company there.
But 2C is enough to do real damage to poor regions and cause more than an inconvenience to other, richer areas. I think it is worth investigating and preparing for. I think it is worth taking measures to prevent what we can and reducing the impact where we cannot prevent it.
This is the second half of the Lukewarm proposition–we believe that sensitivity is lower than activists have tried to proclaim by fiat, but we also believe that even lower sensitivity can bring about enough warming to cause real harm and to spur us to action now.
If Mr. Ridley claims the Lukewarmer badge of honour but doesn’t agree with the second half of the proposition, he might well be the first to do so. We don’t have club rules or a creed written anywhere, but even so, it would be remarkable for him to assert as he does that 2C will bring net benefits and still maintain he’s a Lukewarmer.