NCAR 2030-2039 drought projection

During the Cold War, one of the leading ideas and acronyms was MAD: Mutually Assured Destruction. The idea was for both sides (the US and the then-USSR) to have so many nukes that it would be, well, MAD for either side to start anything serious. A nuclear exchange would utterly destroy both sides.

Today, we have a MAD-type situation with carbon emissions. The major polluters – the US and China in the first rank – are each emitting enough CO2 to put us beyond the “safe” limit of +2C of total warming. (We’ve already had +0.8C, and are starting to suffer serious consequences, with at least +0.6C in the pipeline if emissions stopped tomorrow.) Europe and European Russia, together, make up a third major player that roughly equals the US and China in CO2 emissions.

Now, let’s play a MAD-type game: In a full-on, unrestricted exchange of CO2 emissions, as we are currently seeing, who suffers least?

For reference, I’ll introduce a chart from the US National Center for Atmospheric Research (NCAR): as the name implies, the leading, non-partisan center of its type. They’ve used current projections of CO2 emissions to project drought severity throughout this century. (I’d argue that the CO2 projections are low, and they don’t include the impact of possible feedbacks from northern permafrost melting and so on.) For more on this series of charts, visit here.

Here’s a quick summary of projected conditions in the three major polluting regions in the 2030s:

• US: Severe drought (Palmer -3 or greater, pink to red to purple) over much of the US. Mexico faces severe drought everywhere. Canada, though, sees increased precipitation in the north.
• China: Severe drought in major agricultural regions in south and east; increased precipitation in northeast and parts of west.
• Europe: Severe drought throughout Spain, Italy, and Greece as well as Turkey; increased precipitation in Northern Europe and most of Russia (European and Asian).

The US, China, and southern Europe all face severe drought problems in the 2030s. For perspective, the US Dust Bowl of the 1930s, which was hugely disruptive, averaged a -3 on the Palmer Scale. Only Canada and Russia have overall increases in precipitation that could maintain or even possibly increase agricultural production. (Barring the effects of unstable weather and the potential for political disruption and war.)

NCAR’s projections have not yet been converted into projections of agricultural production. However, a quick look at the chart argues for the following coping options for each country:

• US: Go north. The US will face severe immigration pressure from Mexico, to the south, and needs to help increase agricultural production in its own north and in Canada. The US needs to lock up agricultural projection from Canada, which could be accomplished by some combination of spending money and applying military pressure.
• Europe: No good answer. The rich agricultural areas in southern and central Europe will be severely impacted, while the smaller areas of land in the north will gain some precipitation. (The mapping style of the NCAR maps greatly exaggerates the land area of far northern regions.) Russia will gain precipitation, but militarily can overpower Europe. So Europe may be dependent on Russia for food tomorrow in the same way it is for natural gas today.
• China: No good answer. The country is hit almost as hard as the US by drought, but with many more people to support. Going north into Siberia is not an option – nuclear-armed Russia is already resisting immigration and investment into Siberia from China. (I saw a surprising influx of Chinese nationals in Siberia on a visit a few years ago.)

So, ironically, the US – which owns the lion’s share of historic CO2 emissions – seems to have the best options for coping with severe impacts from global warming up to the 2030s. Russia, with emissions at the same per capita level as the US, could benefit greatly from food sales. Europe – at half the US’ emissions levels – and China, still below even Europe in per capita emissions, look to suffer most.

The bottom line is that the US “wins” the MAD race. With better options than other major emitters, from a national power point of view, the US could come out “ahead” by suffering somewhat less. It won’t be much fun to be an American through the rest of this century – but it may be even less fun to be a citizen almost anywhere else.

• The environment absorbs less CO2. About 50% of our current emissions are absorbed by the environment – roughly half of that by the oceans, the other half by plants on land. This uptake of CO2 by the environment may already be in decline.
• Reflection of sunlight drops. As snow and ice cover retreat – as cover is smaller in geographic extent, or seasonal cover lasts for less of the year – dark ground and even darker water are exposed, which absorb sunlight, further warming the earth.
• More CO2 and methane are emitted from nature. Soils, forests, peat, the seas, organic deposits in permafrost, and methane clathrates all emit some CO2 and methane. As the environment warms, “natural” emissions increase.

Less uptake of CO2, plus less reflecting of sunlight, plus more CO2 from nature, can add up to a self-sustaining cycle. Once begun, it might well not end until the uptake of CO2 by nature has largely stopped, there’s very little snow and ice left to reflect sunlight, and stored deposits of CO2 and methane are largely depleted.

When this has occurred, our planet would be a very different place. It might be 5-10C (9-18F) warmer, bereft of most of its living species, and substantially desertified, for a very long time to come.

In its 2007 Report, the Intergovernmental Panel on Climate Change, or IPCC, warned that global warming must be kept at less than 2C (3.6F) to give humanity a 50/50 chance of avoiding runaway climate change. This raises three questions:

• Is 50/50 a chance we want to take?
• Might the climate be more resistant to warming, perhaps giving us more breathing room?
• Might the climate be less resistant to warming? In particular, might runaway climate change have already begun?

This blog’s job is to help investigate these questions, from a science and technology journalist’s point of view. That is, not to do the scientific work to answer the question – no one person could do that – but to review the work that has been done, and new work as it comes along, with a view to answering this question.

I’ve already done a preliminary survey, and made some initial calculations, in my book, Runaway. My current hypothesis – and my personal belief – is that runaway climate change is inevitable, even if emissions from humanity stopped today.

I believe even more firmly that humanity will not do anything resembling halting emissions today, but will emit much more. Even if I’m wrong, and we still have a margin before runaway warming begins, we’re certain to bust right through it before we get a handle on our emissions. If and when we do so, we’ll then have to stop the mightiest genie ever let loose from any bottle, before it permanently changes the earth, and eliminates most or all of us in the process.