A new study blames volcanoes for the lack of global warming since 2000. This continues an interesting trend in the realm of climate science.
For years, climate change skeptics have been claiming that the earth has been failing to warm as scientists predicted. Climate change defenders have been accusing them of fabrication and cherry-picking, insisting that all the Smart People all agree that the Earth is still warming and even accelerating!
Meanwhile, behind the scenes, more and more scientists are coming up with theories to explain why there hasn’t been any warming lately. Maybe it’s pollutants in Asia. Maybe it’s hiding deep in the ocean. This time, maybe it’s volcanoes. Increasingly, the scientific community seems to be subtly abandoning the old argument that “the planet is definitely still warming, and anyone who doubts the consensus is anti-science,” in favor of a new argument that “the planet doesn’t appear to be warming, but climate change is still true, and here’s the reason for this unexpected pause.”
What I find funny about this shift is that it quietly admits that skeptics were right about the lack of warming. You cannot switch from arguing that there has been no pause in warming to arguing that the 15-year pause has a very good reason without betraying that you were wrong about there being no pause! (It also makes one wonder what to do with all the disasters that have been attributed to global warming since the turn of the century, from the European heat wave to Katrina to the Russian heat wave to the Texas drought to Sandy to everything else, if there wasn’t actually any warming going on.)
Now I’m no scientist. Maybe pollution can both cause global warming and stop global warming. Or maybe all the extra heat just happens to be hiding in the only place we don’t have really good measurements. But this new volcano theory really seems like stretching to me – especially because it does not seem to be accompanied by any evidence that volcano eruptions in the last decade were any greater than usual.
At a cursory glance, the list of large eruptions in the 2000’s decade does not seem to be that much larger than the list of eruptions in, say, the 1980’s – certainly not enough to make up for a 35%+ rise in carbon emissions. Maybe they’re talking about a whole bunch of smaller ones. Maybe the world is complicated and there are several contributing factors. But it sure feels like a weak attempt to fit contradictory data into a pre-existing belief-set.
Now, if a belief-set is consistently supported by independent observations across the scientific spectrum, all reinforcing each other with consistent evidence, and a little bit of inconsistent evidence comes along, it is probably rational to assume that the belief-set is still correct but that some of the details are incomplete, and to look for a way to explain those details. This is how a lot of science works.
However, I also believe that humans are creative enough, and the world complex enough, that people can cleverly defend an existing belief-set against almost any individual piece of contradictory evidence. In this case, first we had scientists denying that there was any contradictory evidence, and now we have scientists admitting that it is contradictory but insisting that it can be explained away due to factors previously unconsidered.
That may be so. But if someone successfully folds contradictory observations back into their existing belief-set enough times, you might start to wonder how many factors they’ve been missing. You might want to step back and question just how many of those original supporting observations were really supporting, and how many of them were just neutral or even contradictory observations that were fit into the belief-set, making it seem a lot more robust than it really is…
I think volcanos cause cooling in the short run, as the ash clouds block the sun’s rays. I’ve tried to avoid the “Is the planet warming” question, as an economist, and focused on the “can we show it would have large costs?” question. Even if the planet gets 3 or 4 degrees warmer, it’s really hard to show there would be net losses for humanity.
Yeah, temperatures dropped noticeably temporarily following the 1991 Pinatubo eruption. But I’m not convinced there were enough volcano eruptions in the 2000’s to cancel out the warming that volcano eruptions in the 80’s and 90’s didn’t cancel (even with Pinatubo). I’m more interested in the “is the planet warming” question for philosophical reasons, as I’m interested in the limits of human knowledge, especially with regard to things we can’t directly observe but are inferred from models, estimates, extrapolations, etc. There are political implications, as those who are most confident in their knowledge tend to be the ones most likely to support coercing others based on that knowledge. There are religious implications as well.
Economically, though, I agree that the question of costs is more interesting. I tend to like Matt Ridley’s writings on the topic. I think the biggest negative could be sea level rise, which if it pans out as predicted could affect the large concentrations of humans on coasts. Though even the most pessimistic predictions have it happening slow enough that, combined with the compounding march of innovation and productivity, humans should have little problem responding. I suppose there is also the possibility of “more extreme weather” destroying all the crops that would otherwise be gained by increased farmland and higher CO2, but I’m unconvinced that the data so far actually shows any increase in extreme weather.
I think volcanos cause cooling in the short run, as the ash clouds block the sun’s rays. I’ve tried to avoid the “Is the planet warming” question, as an economist, and focused on the “can we show it would have large costs?” question. Even if the planet gets 3 or 4 degrees warmer, it’s really hard to show there would be net losses for humanity.
Yeah, temperatures dropped noticeably temporarily following the 1991 Pinatubo eruption. But I’m not convinced there were enough volcano eruptions in the 2000’s to cancel out the warming that volcano eruptions in the 80’s and 90’s didn’t cancel (even with Pinatubo). I’m more interested in the “is the planet warming” question for philosophical reasons, as I’m interested in the limits of human knowledge, especially with regard to things we can’t directly observe but are inferred from models, estimates, extrapolations, etc. There are political implications, as those who are most confident in their knowledge tend to be the ones most likely to support coercing others based on that knowledge. There are religious implications as well.
Economically, though, I agree that the question of costs is more interesting. I tend to like Matt Ridley’s writings on the topic. I think the biggest negative could be sea level rise, which if it pans out as predicted could affect the large concentrations of humans on coasts. Though even the most pessimistic predictions have it happening slow enough that, combined with the compounding march of innovation and productivity, humans should have little problem responding. I suppose there is also the possibility of “more extreme weather” destroying all the crops that would otherwise be gained by increased farmland and higher CO2, but I’m unconvinced that the data so far actually shows any increase in extreme weather.