Global Warming: Not Reversible, But Stoppable

Originally posted at Skeptical Science

Let’s start with two skill-testing questions:

1. If we stop greenhouse gas emissions, won’t the climate naturally go back to the way it was before?

2. Isn’t there “warming in the pipeline” that will continue to heat up the planet no matter what we do?

The correct answer to both questions is “no”.

Global warming is not reversible but it is stoppable.

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Modelling the permafrost carbon feedback

Originally posted at Skeptical Science and reposted at Climate Progress.

A recent modelling experiment shows that climate change feedbacks from thawing permafrost are likely to increase global temperatures by one-quarter to a full degree Celsius by the end of this century. This extra warming will be in addition to the increase in temperature caused directly by emissions from fossil fuels.  Even in the unlikely event that we were to stop all emissions in the near future, this permafrost climate feedback would likely continue as a self-sustaining process, cancelling out any future natural draw-down in atmospheric carbon dioxide levels by the oceans or vegetation. Avoiding dangerous climate change by reducing fossil-fuel emissions becomes more difficult once permafrost emissions are properly considered. 

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