MIT in Journal of Climate: 10°F Warming by 2100

Posted on June 21, 2010 in What is RCC

An MIT report says the world is on track to get much warmer, much faster. An increase of +9F this century is predicted – nearly 1F per decade. This is on top of the 1F increase seen between pre-industrial times to 2000, for total global warming of 10F by 2011.

Total warming of 10F means a very different world, one in which the natural world is decimated and feeding current and projected populations is impossible.

The report, which was the subject of stories earlier this year, has just been published in the prestigious Journal of Climate. If the report is correct, the survival of most people on Earth is at risk. A 10F warmer planet will support many billions fewer people, and with a transition period quite possibly marked by massive war and conflict. Any steps that save many lives are likely to be so draconian as to feel like wartime, even if implemented as benignly as possible.

The natural environment would become unrecognizable and sparse, with no time available for migrations and evolution to preserve anything resembling current diversity.

The projected increase is much higher than projected in a 2003 study by the same group, which projected roughly half the warming. (Even the 2003 MIT results were higher than those used in the IPCC 2007 reports and Al Gore’s An Inconvenient Truth.)

What’s changed is a better understanding of how much CO2 growing economies are likely to emit (backed up by big recent increases from India and China), more knowledge of how some 20th century warming was actually masked by volcanoes – demonstrating high temperature sensitivity to greenhouse gas emissions – and a lowered projection of the rate of heat transfer to the deep oceans.

The warming predicted by the report is also likely to be an underestimate. That’s because the report doesn’t take into account many likely feedbacks from climate change, such as increased emissions of CO2 and methane from melting permafrost in the north. These emissions would likely increase temperatures several degrees further, as unimaginable as that is.

How will the world know whether the MIT report is an outlier, or a new basis for planning in reacting to climate change? Confirmation will require additional work, and new publications, from others. Fortunately, the report comes out in plenty of time to be included in the upcoming 2014 IPCC report, which represents the agreed view of the world’s governments. (Not the world’s scientists, as commonly believed.)

Though strongly conservative, and usually containing underestimates of both current emissions and near-future changes, the IPCC report at least brings together a range of views. In the next report, the MIT results should either be sharply criticized, or substantially confirmed.

If one has to start making bets today, though, the MIT projections are hard to contradict. The report takes into account a wide range of historical data and predictions of current effects that have been tested against emerging realities in recent years. Most climate feedbacks are turning out to be more strongly positive and faster-acting than previously predicted.

For instance, the North Pole’s ice cap was recently predicted to disappear at the end of the century. Scientists have been stunned by its recent collapse, with its disappearance in summertime now projected for perhaps 2030, or earlier. While it’s easy to identify carbon sources, damage to carbon sinks, and interactions that might make things worse, there’s very little that’s obvious out there that would lessen warming – no new carbon sinks that seem to be on the verge of activation, for instance.

In upcoming posts, I’ll discuss the range of policy actions still available and how they might possibly slow – not stop – warming, and how communicators and others should treat this report.