So, the The Intergovernmental Panel on Climate Change, IPCC, the group of international experts that the UN has set up to study Climate Change, launched their last report a few days ago. And things are increasingly grim. You can read the summary of the summary here. These are the key points:
- The planet already warmed 1.1ºC from the pre-industrial (1850-1900) average as a direct consecuence of human activities.
- At the current point, it's impossible to avoid getting to 1.5ºC raise already. That's already unavoidable.
- It's going to be very hard to not surpass 2ºC.
- The policies being adopted worldwide are inconsistent and insuficient.
- To limit the heating to 1.5ºC (which, I must say, 15 years ago was considered "the worst scenario we could shot for") we need the WORLDWIDE CO2 emissions to be cut down by 43% ... by 2030. And 85% by 2050.
And now is where I need to give you some context. Even with the climate policies that have been implemented around the world in the last few years, the global CO2 emission have NEVER gone down consistently. We are just slowing down the rate at which they grow. Even in 2020, with the ... you know, global economy coming to a halt for months, the emissions only got down by 5% from 2019 levels. And in 2021, they went up to the same level again:
To avoid going overshooting a 1.5ºC raise by the end of the century, we need to cut down emissions to ... 1971 levels. In 6 years and a half. That's stepping on the brake pedal HARD, and NOW. Fuck.
FUCK.
Now, a still hard but more feasible scenario is "we don't manage to reduce emissions, but manage to stop them from keep growing and keep the current levels" (again, we are FAR from even achieving that, emissions keep growing every year, at a quick pace). That's what the IPCC calls the SSP2-4.5 scenario. And ... that would mean about a 3ºC raise by the end of the century:
I'm not exagerating when saying that a 3ºC scenario may not put at risk the human existence, but it seriously put at risk the survival of literal billions of people and would mean the end of our global civilization as we know it. Why? because of this, also from the report:
The first bit is scary AS hell. If you haven't heard about the wet-bulb effect, it's one of the most scary thing I've ever read about. Long story short, when our bodies overheat, they use sweat to cool down. The sweat on our skin evaporates, and by doing it, it cools our skin and cool our overall body temperature. Now, the sweat takes more time to evaporate when the external humidity is high, to a point where if the humidity is too high, it doesn't evaporate at all. So if the ambiental humidity is high, our bodies can't cool down effectively.
And this is the scary part: If the external temperature is too high, and the humidity is too high, your body gets heated by the ambiental heat, but can't cool itself down by sweating. So at a certain point... your body just shut down and you die. It doesn't matter how young or healthy you are: That only change how long of exposure to extreme conditions takes to bring you down, but you die anyway.
Now take a look at this:
The number up there is the projections of how many days per year where the combination of external temperature and humidity would make human life impossible. Even at 1.7ºC warming, some of the most populated areas of the planet (coastal India, south Asia, Phillipines, Java, etc) will be uncompatible with human life for half the year. That's a couple of billion people that either relocate or die. And that's with the absurdly optimistic expectation that we can go back to 1971 emission levels in ten years or so.
And then it's the second part, the food production impacts. At 1.7ºC, the corn production of US and China will be down by about 15%.
At 3ºC? by 30-35%. Any other crop you can think about is in the same situation. This means famines. Famines as they have never been seen in recorded human history (as they are not caused by puntual events like pests, weather or mismanagement: They will be structural, permanent).
And folks, this is not politics, this is not being paranoid. This is a group of scientists doing peer-reviewed science. This is not "we think this may happen", this is "Given X then there's a 95% of probabily for Y to happen". And let's remember, this reports have been going on since the 90s, and for the last 30 years their forecast of temperature changes HAVE BEEN FUCKING ON POINT.
And not, it's not being alarmist or pesimist to talk about the 3ºC increase and its effects. At this point? it's BEING FUCKING OPTIMIST. Because we are not even on track to limit the warming to the level that would mean several billion humans death by the end of the century. We are not even in track to that.
