The Slow Moving Apocalypse has Arrived
Climate change is already harming millions in the global south
Because of your generous support for CTAN, I spent part of my vacation last week reading the IPCC AR6 Summary for Policymakers. So far, I’ve only read about 10 pages out of 36. (I didn’t say I would read it quickly.) And, as promised, I wanted to share with you some thoughts about what I’ve read so far.
First, this is an incredibly depressing report (or “sobering” as they say in journalism.) This apocalypse may be slow moving, but it is definitely starting to pick up. Consider this figure (SPM 1 in the report):
My kids were born in 2016, and by the time they’re adults, the world will probably be about 2 degrees warmer than it is right now. Fortunately for my kids, they live in the Global North, and will probably be mostly okay. But not everybody is so lucky:
Approximately 3.3–3.6 billion people live in contexts that are highly vulnerable to climate change…Increasing weather and climate extreme events have exposed millions of people to acute food insecurity and reduced water security, with the largest adverse impacts observed in many locations and/or communities in Africa, Asia, Central and South America, LDCs, Small Islands and the Arctic, and globally for Indigenous Peoples, small-scale food producers and low-income households. Between 2010 and 2020, human mortality from floods, droughts and storms was 15 times higher in highly vulnerable regions, compared to regions with very low vulnerability (high confidence).
(Emphasis mine.) Lots of people all over the world are suffering the consequences of climate change, but most of those people aren’t in North America. In fact:
The 10% of households with the highest per capita emissions contribute 34–45% of global consumption-based household GHG emissions, while the bottom 50% contribute 13–15%. (high confidence).
Notice also that these conclusions are written in the present tense: Increasing weather and climate extreme events have exposed millions of people acute food insecurity and reduced water security. This is not a theoretical future we’re talking about:
Evidence of observed changes in extremes such as heatwaves, heavy precipitation, droughts, and tropical cyclones, and, in particular, their attribution to human influence, has further strengthened since AR5. Human influence has likely increased the chance of compound extreme events since the 1950s, including increases in the frequency of concurrent heatwaves and droughts (high confidence).
One interesting thing about the IPCC report is that every single statement is followed by an estimate of their confidence in the correctness of the statement. Both of these are marked as high confidence. Just in case you’ve been duped by the Wall Street Journal editorial page1, there is very little doubt that we are currently experiencing the effects of climate change, and that those will continue to get worse unless we reduce emissions. People like to argue about whether specific weather events were caused by climate change, but that’s like arguing over how many angels can dance on the head of a pin, except that the argument in this case is taking place in a frying pan and the heat is being turned up slowly but inexorably. There is never a singular cause for any event (especially weather events, which arise from complex dynamics of the climate system). But that doesn’t mean we can’t observe the increase in the rate of severe weather events, and draw scientifically-based conclusions about the cause2.
I’ve been called a pessimist for my hot takes about why we shouldn’t rely on altruism and personal choice to unbork the climate3. But it’s very clear from the IPCC report: the people making the CO₂ are not the people being impacted but climate change. And I believe it’s stupid bordering on immoral to try to pretend that that’s not a huge impediment to climate action. Our solutions to the climate crisis should not be based on how we would like the world to be, but should be based on what is most likely to help the most people. The only way to practically prevent massive human suffering is to reduce CO₂ emissions drastically, and technology is the fulcrum we can use to try to speed that outcome.
I’m looking at you, dad.
This lies at the heart of the Frequentist vs Bayesian debate: how we think about the relationship between individual events and statistics of large numbers of events.
I always say that I’m not a pessimist, I’m a realist. But, all pessimists say that.