Professor Mark Cochrane’s perspective on ‘certainty’!
I’m an avid follower of Mike Stasse’s blog Damn the Matrix. So it was rather fortuitous that two days ago there was a guest post on Mike’s blog from Mark Cochrane. Dr. Mark Cochrane is a Senior Scientist and Professor at South Dakota State University where one can read:
Dr. Mark Cochrane conducts interdisciplinary work combining ecology , remote sensing, and other fields of study to provide a landscape perspective of the dynamic processes involved in land-cover change. He is an expert on wildfire, documenting the characteristics, behavior and severe effects of fire in tropical and temperate forests that are inherent to current systems of human land-use and management. His research focuses on understanding spatial patterns, interactions and synergisms between the multiple physical and biological factors that affect ecosystems. Recently published work has emphasized the climate change, human dimensions of land-cover change and the potential for sustainable development.
The guest post was called Doom and Denial two sides of the same coin; I’m extremely grateful to Mike Stasse for granting me permission to republish the essay.
Doom and Denial two sides of the same coin.
19th June 2013
Another guest post by Mark Cochrane…… and I hope Guy reads this, I’d like his feedback, no pun intended!
I’ve been asked by several people to address the take of climate ‘doomists’ like McPherson and indicate how my views on what the science indicates differ. First, let me just say that my differences with the doomist views are similar to my differences with the ‘denialist’ views, namely one of actually examining the scientific findings and concluding what they signify versus beginning with a conclusion and looking for evidence to support a pre-concluded viewpoint.
Appropriate use of science (or any information), requires weighing anything being newly reported against the rest of the accumulated evidence on a subject (e.g. climate change) that we have amassed, to date, and using this knowledge to infer the most probable meaning and significance. How credible is the source, how relevant are the results to the larger question, do the new results substantially change our previous understanding? If someone is presenting new ideas that claim to massively shift what we think we know about the world, have they been vetted (e.g. peer-reviewed), do they adequately explain how their new claims better explain observed phenomena than previous studies did and also detail why previous explanations were somehow erroneous? If the results are truly stunning, can they be replicated by others? Although some may find it hard to believe, there is a lot of space between climate denial and climate doom.
I’ve only seen the one talk now by McPherson but where the ‘we are doomed and soon’ meme falls apart is on general logic. You cannot say, there are positive feedbacks A, B and C, therefore life on Earth is suddenly going to end without considering:
- what are the current rates of those feedbacks,
- what is the rate of change for the feedback,
- what is the area affected by the feedback,
- what natural limits exist for the feedback,
- what negative feedbacks might occur in response?
If you listen to McPherson’s talk, what you get is a litany of disturbing findings, especially feedbacks, and then an expectation that you must reach the same conclusion that we are doomed, and soon. If someone would like to outline the chain of logic used, I’d be happy to discuss it. Even if you accept the chain of logic though, where, in any of it, is there evidence for the timeline being suggested?
There is considerable amount of concern about the feedbacks in the Arctic, with good reason, but people do things like linking the large amount of carbon stocks in the Arctic with rapid warming, with increased rates of release, with increased rates of warming……with the obvious end of all life on Earth – near-term extinction!
As anyone who has followed this thread knows, I am usually the one pointing out feedbacks and how most are not even included in current climate projections, in contradiction to those who claim such dire projections are all because of such feedbacks (which ‘skeptics’ claim don’t exist). This does not mean though that the existence of feedbacks means that we can then make the leap to a runaway greenhouse that will soon lead us to having the climate of Venus (atmospheric acid bath at temperatures that would melt lead). Perhaps providing some perspective on the recent material posted about the NASA CARVE project and what it means for all of that carbon in the (not so) permafrost will help.
As NASA recently reported (site),
“Over hundreds of millennia, Arctic permafrost soils have accumulated vast stores of organic carbon – an estimated 1,400 to 1,850 petagrams of it (a petagram is 2.2 trillion pounds, or 1 billion metric tons). That’s about half of all the estimated organic carbon stored in Earth’s soils. In comparison, about 350 petagrams of carbon have been emitted from all fossil-fuel combustion and human activities since 1850. Most of this carbon is located in thaw-vulnerable topsoils within 10 feet (3 meters) of the surface.”
“Permafrost soils are warming even faster than Arctic air temperatures – as much as 2.7 to 4.5 degrees Fahrenheit (1.5 to 2.5 degrees Celsius) in just the past 30 years,” Miller said. “As heat from Earth’s surface penetrates into permafrost, it threatens to mobilize these organic carbon reservoirs and release them into the atmosphere as carbon dioxide and methane, upsetting the Arctic’s carbon balance and greatly exacerbating global warming.”
In other words, there is 4-5 times as much carbon sitting around in those frozen soils as we have already emitted that are becoming increasingly vulnerable to being thawed out for a portion of each year.
Once those soils thaw they become accessible to microorganisms that feed on the incompletely decomposed plant materials that they contain. If there is sufficient oxygen (warm relatively dry Arctic) the process is faster and the product is CO2, if the process is anaerobic (warm relatively wet Arctic), then the product is methane.
So warming leads to thawing, thawing leads to microbial decomposition, and microbial activity leads to carbon emissions. These emissions are a positive feedback that makes the current process of greenhouse gas warming worse since each degree of warming yields more greenhouse gases that speed up the warming process further. This is where the message of doom goes off the tracks and extrapolates erroneously that this somehow means that all of that carbon is going to suddenly find itself in the atmosphere.
Three meters (10ft) of soil carbon doesn’t just suddenly evaporate into the atmosphere in the next few years. Thawing permafrost is not synonymous with melting carbon. Even once permafrost melts, it is still very cold. However, bacteria can start digesting it – until it freezes again. Melted permafrost does not mean permanently melted. The surface layer of the Arctic lands are already in the active layer that temporarily thaws each year and then refreezes. Now, we are making more of the Arctic soil active to greater depths and at higher latitudes. This means that there will be more emissions from those soils.
Taken out of context snippets like this (below) from that NASA press piece can be made to sound catastrophic.
“Some of the methane and carbon dioxide concentrations we’ve measured have been large, and we’re seeing very different patterns from what models suggest,” Miller said. “We saw large, regional-scale episodic bursts of higher-than-normal carbon dioxide and methane in interior Alaska and across the North Slope during the spring thaw, and they lasted until after the fall refreeze. To cite another example, in July 2012 we saw methane levels over swamps in the Innoko Wilderness that were 650 parts per billion higher than normal background levels. That’s similar to what you might find in a large city.”
Parsing the quote, please note that “episodic bursts of higher-than-normal carbon dioxide and methane” in two locations (regions) does not mean the end is nigh. Higher-than-normal is just that, but how much higher and how long did it last? The scientists are saying that the observations do not match existing ‘models’ (models are wrong, a favorite meme), it doesn’t mean that such events haven’t been happening up until now (only that we didn’t know about them). As for the 650ppb increase over a swamp, that equates to being 1/3 higher than the background level. Methane and swamps go together so some higher level is to be expected. The question is if and by how much 650ppb is higher than it would have been back around 1980 or so? If it used to be 10ppb higher than background then you have a big change (640ppb), however, if it used to be 640ppb, then not so much (10ppb difference). Even if that is all new carbon being emitted, the local change becomes very small when diluted globally. The point here is not to poo-poo the findings or the scientist’s work, they are doing very important stuff (!), it is to provide context.
Just how bad could things be? I do not work in the high Arctic but I do work in similar organic soils in the tropics (peat swamps) where, because of intentional draining, the several meter thick peat layer that is ‘active’ is increased in an analogous manner to the effects of melting permafrost. Microbial degradation is occurring, with the difference that the temperature is very warm instead of being very cold. Think of how fast fruit spoils in your refrigerator versus on a hot window sill. In these tropical peat soils we see large amounts of CO2 coming off into the atmosphere each year now, but even with such large rates of loss, this equates to taking about 20-25 years to lose 1 meter of organic soil. In the Arctic the microbial degradation will be much slower due to the relatively low temperatures. This doesn’t mean that it is not important. Slow rates of emissions over a large area is still a lot of extra carbon going into atmosphere but this is a problem that is going to take centuries to play out, not less than a decade. It makes things worse but it doesn’t suddenly end life on Earth.
Incidentally, all of that soil carbon in the Arctic isn’t a uniform petri dish either. Some of that carbon is easier to access by bacteria than other portions. Emissions will rise quickly as the bacteria chew through the cellulose, for example, but things like lignin get left behind. The point being that even for a given mass of carbon in the ‘active’ layer, there will be a dampening of the emissions growth rate as the quality of the bacteria buffet goes down when it gets picked over.
I do not pretend to know what the motivations of ‘doomists’ are, whether it be honest despair or simple misunderstanding but they are conveying the same message of do nothing as those who deny the existence or importance of climate change. Denial = don’t worry be happy, while Doom = don’t worry, you can’t do anything about it anyway. Both viewpoints are wrong in trying to turn climate change into a false dichotomy of either fantasy or inevitability. Both the science and our choices are much more complicated. It’s uncomfortable but your choices do matter now and for generations to come. There is no ‘fixing’ things at this point but you still have the ability to choose how you react to the predicament we have created. Doom and denial are respectively trying to tell you that you either have no choice or no need to choose. But, as Philip K. Dick wrote:
“Reality is that which, when you stop believing in it, doesn’t go away.”