Emissions from permafrost put the 1.5o climate goal out of reach


President & Executive Director Philip B. Duffy

As you know if you read our news, WHRC has recently been instrumental in getting the issue of greenhouse gas emissions from arctic permafrost on the radar screens of high-level US policy makers. This is good, but the implications of those emissions for stabilizing climate at an acceptable level aren’t. This was driven home to me recently as I prepared a short talk which I later gave at the University of Chicago. There I showed a simple graphic which makes it clear that expected emissions from permafrost during the remainder of this century (never mind subsequent emissions, which may be much greater) make it impossible to limit global warming to 1.5o C. Even 2o of warming, which may result in some very serious harms, will be very difficult to achieve. This is probably true even if we make heroic efforts to pull CO2 from the atmosphere by aggressively reforesting the tropics, as we have advocated. This is a big deal, because, although we don’t understand as well as we should the consequences of 2o of warming, it looks more and more like some of them could be really bad — like the complete melting of the Greenland ice sheet, which would eventually result in 23 feet of sea level rise.

Given this, I am left wondering why the Paris Agreement bothers to mention the value of “efforts to limit the temperature increase to 1.5o C,” and why it bothers to suggest that the UN scientific body on climate change (the IPCC) do an analysis comparing the impacts of 1.5o of warming to those of 2o. I can guess that this might have been a diplomatic gesture to countries that are distressed at the implications for them of 2o of warming. (Shockingly, none of my contacts in the State Department is willing to comment about this on the record.)

We should all be clear that it is most likely too late to limit global warming to 1.5o C. Personally, I am still digesting the implications of this, but it seems to suggest some urgent priorities:

Elimination of fossil fuel use should be put on a “war footing.” That is, it should be something we do because we have to, without requiring, for example, that the cost per kWh for solar-generated electricity be less than that produced using gas. Just do it! The necessary investments include not only deployment of renewable generation capacity, but a better electrical grid, and research into better renewable technologies.

We need to use every means possible — and others that are not yet possible — to pull CO2 from the atmosphere. As we’ve shown here at WHRC, aggressive reforestation can help, and the physical and ecological co-benefits should be substantial.

We need more research to understand greenhouse gas emissions from arctic permafrost. Is there really a possibility of a self-reinforcing cycle of warming -> permafrost thaw -> warming? If so, we need to know this, and how to prevent it. This is another area where the WHRC is at the scientific forefront.

George Woodwell may never talk to me again, but I think it’s time to investigate how we might “alter the radiation balance” (e.g., reflect more sunlight back out into space), especially in the Arctic. If emissions from permafrost really have the potential to become uncontrollable, we need a plan to deal with this. I am no fan of (additional) messing with Mother Nature, but it’s time to think the unthinkable.

We also need to understand what the world looks like with 2o, 2.5o, and 3o of warming, both immediately and later, after the climate system has fully adjusted. How high will the sea level be? How many species will have become extinct? What will extreme weather risk look like? These are not the only negative impacts of climate change of course, but they may be the most difficult to adapt to. Crop yields will be reduced, for example, which is a serious issue, but also one that human ingenuity can probably deal with.

This may seem distressing, but there’s more reason for hope now than in a long time. The Paris Agreement offers a real possibility of controlling climate change, albeit not at the level we might like. There’s more policy action now at the national and subnational level than ever, including cap and trade systems and carbon taxes. This is reflected in the latest greenhouse gas emissions, which for the first time ever seem to be poised to go down without an accompanying decline in economic activity. We can fix this if we try; what scares me is the possibility that we won’t, because our leaders either refuse to recognize the problem or refuse to mobilize to tackle it.