Article thread | Points of No Return

Great (long) summary of 7 of the most important climate tipping points.

1/14 https://twitter.com/grist/status/1385669938010984450

2/14 Consider the following coin flip bet: pay 𝘅 & get:
- 𝟭𝟬𝘅 on head
- 𝟬 on tail.

Should you play? Expectation is a profit of 𝟰𝘅.

The answer is: it depends. If losing 𝘅 would bankrupt you, do not play.

Life/death decisions are difficult to "optimize".

3/14 Nature plays in a different league re energy: "Scientists estimate that the energy [the Gulf Stream] transports is roughly equivalent to the power provided by 1 𝘮𝘪𝘭𝘭𝘪𝘰𝘯 average-sized nuclear plants".

(The world economy runs on the equivalent of ~17k nukes.)

4/14 Coral reefs feed 500MM people.

5/14 Tipping points are surprise packages, it's difficult to know when they will trigger. Possibly still in a few decades or maybe they are already close to triggering. C.f. Greenland.

6/14 Or worst case, tipping points have already been triggered (cc Nordhaus), c.f. West Antarctica potentially raising sea levels by a few feet...

7/14 ...or same with permafrost melting, now adding 0.3 - 0.6 GtCO2/year (total anthropogenic emissions are 50 GtCO2(eq)/year).

8/14 Over longer time periods (who cares about life in 100 years anyway?), a lot more can obviously come "online".

9/14 With side effects like more frequent "zombie fires".

10/14 Some feedbacks are negative though (i.e. not reinforcing/slowing), e.g. shift in vegetation that might actually store more carbon.

11/14 The broad trend is that it's likely to go in the wrong direction. A gigatonne here, a gigatonne there and it starts to add up...

12/14 ... especially as more sources turn from carbon sinks to carbon sources; e.g. potentially the Amazon rainforest by 2035. (Will carbon offsets still work there if they bear "negative interest rates"?)

13/14 And some other fancy non-climate-related tipping points for rainforests.

14/14 The first rule of Fight Club is...