For those of you reading this in 2035, a glacier is like a big natural ice cube in a mountain valley.
But what about 2 or 3 degrees?
Aren’t we way past the point of being able to limit it to that anyway?
In theory, no. There’s actually a tiny bit of runway left. If carbon emissions continued as today for about 2 or 3 years (extrapolate figures) and then stopped, the temperature would plateau at 1.5 and then very slowly fall.
Of course, the problem is that emissions are absolutely not going to stop in 2027.
BTW: current average projection is around +3.5 by century’s end. That’s actually a bit lower than it was a few years ago, due to faster than expected roll-out of green tech. But it’s obviously still way, way too high. Especially because of the risk of tipping points.
According to the paleoclimate data, the CO2 levels of today get you an equilibrium of 10° of global temperature rise. It takes about 100 years before the climate response happens.
https://academic.oup.com/oocc/article/3/1/kgad008/7335889?login=false
And yet, says the same article:
Equilibrium warming is not ‘committed’ warming; rapid phaseout of GHG emissions would prevent most equilibrium warming from occurring.
So something’s off.
Then they go into the details:
We would need rapid phaseout of carbon within a couple decades. Then we need a global program of solar radiation management (geoengineering) with the example of the Pinatubo eruption given to save inundation of the coastal cities. THEN we need to rapidly find a way to do negative emissions and restore the atmosphere to preindustrial.
(Also, equlibrium warming isn’t the only warming at play. You read the whole thing. Right? The other one is ESS, which involves feedbacks.)
If you just read to the end of that paragraph, it concludes with this:
Required actions include: (1) a global increasing price on GHG emissions accompanied by development of abundant, affordable, dispatchable clean energy, (2) East-West cooperation in a way that accommodates developing world needs, and (3) intervention with Earth’s radiation imbalance to phase down today’s massive human-made ‘geo-transformation’ of Earth’s climate. Current political crises present an opportunity for reset, especially if young people can grasp their situation.
And what is ‘committed warming’?
They say:
If human emissions ceased, atmospheric CO2 would initially decline a few ppm per year, but uptake would soon slow—it would take millennia for CO2 to reach preindustrial levels
So the earth would eventually remove the CO2 via natural processes it’s not “committed”. It just takes thousands and thousands of years to go away again.
And yet reliable sources say what seems to be generally accepted, namely that stopping carbons emissions completely in a short time frame (a couple of years) would land us with “1.5 degrees by the end of the century”. So, as I said, something is off with this “10 degrees”. Perhaps it’s the “end of the century” bit.
Correct. The system only goes up 60% of the full temperature forcing in 100 years. So 75 years down the road from today you don’t see most of the temperature change, YET
Point 2: “Reliable sources”. They are likely wrong. Read the paper.
There is major politics and a lot of mistakes. They all downplay the severity for non scientific reasons.
The main human motivator was that if climate change was as dire and as bleak as the science suggested, there would be no hope at all. So nobody ever truly considered these scenarios because it was too scary and too politically impossible. Like…why bother thinking about problems for which there is no solution space? Instead focus on a narrow possibility that we are in a different problem that we have some agency within.
People have been looking at the science to see what they want to hear.
Here is a very clear example…
In this paper, they are talking about a comparison between the PETM and the climate forcing of today.
https://en.m.wikipedia.org/wiki/Paleocene–Eocene_Thermal_Maximum
This had PROFOUND effects on the planet. Anoxic oceans, mass animal mortality, acidification of the oceans, decline of plankton and corals etc etc. Palm trees grew in the Arctic.
I mean…this is human extinction level stuff. They don’t come right out and say it anywhere. But you have to understand the context.
If you want to share where you’re getting the “1.5 by 2100” I can try to dispel the idea more fully. It’s probably a junk source. [*]
[*] In this paper I just linked, they talk about how the pollution that comes with CO2 emissions (soot, dust, smoke and other small particles) acts like a sunscreen, and water vapor also interacts with this dust layer and amplifies the effect, rapidly cooling the planet. They discuss how many of the scenarios where we eg. stop CO2 to limit warming by 2100… DO NOT EVEN CONSIDER that dust will stop, and when dust stops temperature actually ramps up even more quickly than we have ever seen before. The dust contribution is a more rapid effect than the CO2 part. Basically the idea is not even scientific at all.
Point 2: “Reliable sources”. They are likely wrong. Read the paper.
Yeah, no. To be clear, the source I referred to is Our World in Data. It’s widely respected and I have better things to do than second-guess it.
emissions are absolutely not going to stop in 2027.
i mean … hopefully not?
I’m pretty sure they meant the kind that pollute Mother Earth, and contribute to the problem.
Oh, wait… Republican “emissions” do that, too, don’t they?
