Thanks for your comment. Unsurprisingly, I am less optimistic. While I also think that climate news gotten better over the last years, I still think there is a big chance we end up at over 2°C. The Twitter thread you linked to says “It finds that, if all the countries of the world fulfilled their climate commitments, the world would most likely limit climate change to just under 2 degrees C.” That’s quite a big if.
The post by John and Johannes mainly argues that extreme warming is not likely, which I also agree with. However, I see the research gap more in the range 2°-3.5°C.
Finally, even if our median trajectory would aim below 2 °C, we still should do more research above 2°C . Climate damage does increase considerably for higher temperatures and due to uncertainties in the climate sensitivity we still could end up there.
I’m happy to take on your second bet. Let me know how you want to implement that.
I’d also consider the first one depending on the implementation. However, betting is easier if you have lots of money, which I don’t.
Good points, I agree that the articles I linked dont directly imply a less than 50% chance of 2ºC warming.
And FWIW Metaculus disagrees with me here, the community prediction is 85% probability of >2ºC warming.
I still hold my position, where my model is that:
Predictions today are much more optimistic than predictions 10 years ago
I expect that trend to continue, because we keep understimating social and tech progreess
I think that the academic process is biased towards being more pessimistic on climate change than the evidence warrants, because of policy concerns. I still expect them to update in the right direction, but rather slowly.
Let´s go with the second bet since it seems easier to orchestrate.
I´m actually not familiar with how the IPCC exactly reports their distributions. Do you (or anyone else reading this) want to suggest what would be the correct way to read the median temperature increase implied by what would be the 2032 IPCC report?
I get your reasons and I hope I lose the 100 $. I also think the probable temperature for 2100 will continue to go down. However, we still have quite a long way to go to get to 2°C.
The IPCC does not really attach probabilities to temperatures. Therefore, it is not really possible to directly go for the IPCC reports as resolution. One possibility would be the Internationale Energy Agency. They regularly publish estimates of likely temperature trajectories. Their current estimate is that with currently (in 2021) stated policies we’ll get 2.6°C in 2100. We could use the median estimate for stated policies in their report for 2032.
As they have been around since 1974, it seems likely they will continue to exist in until 2032. However, they might chance the way they do their reporting, so I am not sure if this is a great way to resolve this.
Sounds reasonable enough to me.
The bet will resolve in your favor if the median temperature increase in the stated policies scenario of the 2032 IEA report is above 2°C.
If the IEA report does not exist or does not report an equivalent of their stated policies scenario the bet resolves ambiguously.
Very curious to see what will actually happen!
Alright, that’s settled then. Also looking forward to resolution!
Major kudos to both of you for this bet. I’ll probably refer to this thread in future as a great example of respectful, productive disagreement!