This is the "Hothouse Earth" paper that was all over the news yesterday. pnas.org/content/early/… It is a "perspective" piece - basically an essay rather than new modelling or data analysis, in which the authors present an argument supported by existing literature. (Thread)
The authors draw on a very diverse set of literature to paint a holistic picture of how a chain of feedback processes or events could *potentially* take place and lead to very large climate warming once a threshold is passed, and also how the risks of this could still be avoided.
The term “Hothouse Earth” is used to describe the conditions that could potentially occur, which are outside those of cycles of ice ages with milder periods in between that have occurred over the last few hundred thousand years (ie: within the experience of the human species).
A key point is that even though the pathway towards “hothouse” conditions could be started this century (maybe decades?), the extreme conditions themselves would not occur for centuries or millennia.
This does not seem to have been mentioned in media coverage that I have seen.
This does not seem to have been mentioned in media coverage that I have seen.
The authors also state that they are taking a “risk averse” approach in suggesting that 2C global warming can be regarded as a potential “threshold”.
They have not discovered that 2C is the tipping point, just suggested it.
Again this is a key point not made in media coverage
They have not discovered that 2C is the tipping point, just suggested it.
Again this is a key point not made in media coverage
The 2C number is supported by comment and review literature which in itself is based on previous literature, so they have not come up with new analysis supporting this as the suggested threshold.
The authors argue that 2C can still be avoided if humanity takes concerted action to reduce ouor warming effect on the climate.
Personally I find it an interesting thought-piece that is worth reading. Its not new research though.
I suspect one reason it has got so much traction is the use of the "Hothouse Earth" term at a time when everyone's talking about heatwaves.
I suspect one reason it has got so much traction is the use of the "Hothouse Earth" term at a time when everyone's talking about heatwaves.
One thing that strikes me about the "tipping points" literature is that there's a lot of review papers like this that end up citing each other!
Here's one that @dougmcneall, myself & colleagues wrote a while ago onlinelibrary.wiley.com/doi/abs/10.100… (£)
We need more actual research on this!
Here's one that @dougmcneall, myself & colleagues wrote a while ago onlinelibrary.wiley.com/doi/abs/10.100… (£)
We need more actual research on this!
NB. Declaration of interest: one of the co-authors of this paper, Tim Lenton, acknowledges support from my EU project HELIX (High-End cLimate Impacts and eXtremes) @helixclimate helixclimate.eu
