The paper in question called “An earth system model shows self-sustained melting of permafrost even if all man-made GHG emissions stop in 2020”. was published in Nature.com. authored by Jorgen Randers professor emeritus of climate strategy at the BI Norwegian Business School and Ulrich Goluke of the same institute.
The negative response has been unusual, to say the least. From outright rejection to pretty brutal total dismissal is the usual bandwidth for the reactions from experts.
One of the major and most criticized sticking points is the assertion of “self-sustained melting of permafrost.” To be strictly fair to the authors, they do qualify their statements with information about previous overestimates of CH4 (methane) release from permafrost.
Melting permafrost really is rampant, and the effects are pretty bizarre, to put it mildly. Siberia is the classic case cited in media, with good reason. Many reports indicate both past permafrost melts and accelerated melting now. So permafrost isn’t being disproportionately singled out by the paper as a factor in warming; it’s the research conclusions that are driving the controversy.
The problems with the “ it’s too late” scenario
There’s a certain irony in the fact that even the worst case scenarios over the last 20 years didn’t envisage outcomes. The Arctic sea ice disappearing and the permafrost going on the rampage were predicted, but not so fast or so universally. Most of the early global warming predictions were underestimates simply due to the compound effects of warming, i.e., warming driving more warming.
This research, (which does by the way include a lot of qualifiers about its predictions), however, does include a range of highly volatile assumptions. Using the model of all greenhouse gas emissions shutting down right now, the global temperature is predicted to keep rising anyway. This is based on the current heating levels and other self-sustaining/self-reinforcing processes. There is also the issue of the “darkening” of the planet’s albedo, absorbing more heat as the albedo reduces.
(I don’t want to regurgitate the entire paper. Check out the link above and see for yourself.)
The problem with all this is that complex systems are unpredictable, as the authors point out. It’s not just one natural cycle which is heating up, it’s all the natural cycles. A “we can’t do anything about it” finding is also a bit out of whack with the historical record.
Earth’s natural temperatures can and do change like a psychotic yoyo. The bandwidth of temperatures is truly huge. Interestingly, the big heat spikes also drop off pretty fast. There apparently is some mechanism that prevents runaway greenhouse effects from maintaining themselves. That’s probably why Earth isn’t more like Venus. The question is what this mechanism is, and how we get the natural reverse cycle air conditioning working ASAP.
The assertion that stopping emissions would have no effect is simply wrong. It is also missing the principles of basic thermodynamics to expect that ceasing the emission of billions of tons of greenhouse gases would have no effect. The thermal profile of a mix of gases changes when gases are added or subtracted from it. That’s a macro version of high school physics. It’s hard to see why this assertion was included in the finding, which is otherwise a discussion of scenarios.
This paper really creates an argument. It does so by challenging a lot of assumptions, introducing specific elements into the equations and predictions. The problem is that it doesn’t resolve the argument to any degree, pun intended.
Geoengineering is mentioned, cursorily, but let’s face it – Human efforts to correct global warming will require technologies that need developing and testing to have any meaningful impact.
The response has been somewhat overdone. Adding unpredictable elements to global climate science may seem flashy and attention-getting, but there are indications that new factors in warming keep showing up, fast. The fact is that warming is a bandwidth of scenarios, and it’s a bit optimistic to assume all elements in accelerated warming have been factored in. What if there is an additional unknown thermal process that makes warming worse?
I’d put this research into the category of What If, rather than simply ignore it. I see plenty of holes in it, but I also see several annoying, yet-to-be-fully-analyzed phenomena in the mix. At the moment, the net effect of the permafrost melt is actually not quantifiable dramatic and quite frankly worrying. Albedo is definitely an issue, but what do you do about it? Randers and Goluke have raised the very ugly specters of some of the more irritating and potentially dangerous elements in global warming if nothing else.
Let’s stick to the main game, eh? Warming is a process that is very hard to quantify. Predictions are usually wrong, or off to some degree within a bandwidth. While this paper is so very arguable on many levels, it’s also obviously a worst-case scenario, and therefore at an extreme relative to other predictions. Let’s leave it at that, shall we, and try to focus on what’s actually happening.
My one major criticism of the paper is that saying it makes no difference if global emissions are cut doesn’t help at all and is fundamentally wrong. Getting rid of all that pollution and associated can only help.
