4 ms·

I don’t think 1.5 degrees is likely at all to happen. We’re already at 1 degree, and because of lags in the climate system we’ve already put enough CO2 in the

I don’t think 1.5 degrees is likely at all to happen. We’re already at 1 degree, and because of lags in the climate system we’ve already put enough CO2 in the atmosphere to bring us to 1.25 even if we stopped all emissions right now. If we were to turn around on a dime and emissions fell just as fast as they went up, that would mean we would be at the halfway point now, in terms of co2. Then the final value would be 540 ppm; almost one doubling. So, 2.75 degrees of warming or so. Even that feels like a pretty optimistic scenario to me though. It’s more likely that it plateaus for a while before declining. So then we might end up 670ppm. That’s 1.25 doublings. That’s about 3.75 degrees. I’d guess that we’ll land somewhere between those two, closer to the 3.75 degrees side. Edit: corrected a math error

dwheeler 5y ago
I agree, stopping at 1.5 C is extremely unlikely. You have to get worldwide agreement to do very hard things. I see little appetite for that. I also don't see any way to make it less hard, though if there is any hope that's where it lies.
- benjohnson 5y ago
  There's a lot of room for hope - I don't really care* global warming, and I'm getting solar on the house in five years because it's disturbingly cheap and will be driving an electric car because they're less maintenance. There's going to be a lot of moving away from oil - because refining sludge from the ground and transporting is expensive compared to the competition. Also... there's a heck of a lot of Nuclear Fusion research going on where I live. I wish them well! *I do care, but it's in the abstract. I kinda like not living in an ice-age. Normally, the land where my house sits is under 1.5 miles of ice.
cableshaft 5y ago
Plus there's the positive feedback loops, so even if that's the natural course we're on, it will lead to changes that will result in even further warming, i.e. no ice to reflect the suns heat, so we absorb more heat, and the methane released by the melting gas, amongst others (there's quite a few of them). From what I've been reading, it seems like if we get up to 2 degrees, the positive feedback loops would probably keep us going up to at least 4-5 degrees.
- deleted 5y ago
  [deleted]
- fallingfrog 5y ago
  That might be, but as far as I can tell that’s not considered a certain conclusion and I don’t consider myself qualified to judge how likely it is.
- yread 5y ago
  There are also lots of negative feedback loops - photosynthesis, cloud albedo, radiation, oceans, at some point human population might start shrinking...
willmadden 5y ago
We are heading into a grand solar minimum. My prediction is that the earth will be cooler in ten years. Check back in 2031 to see if I’m right. I’m far more worried about the magnetic pole shift and what that could mean about our sun.
- kelp 5y ago
  Was trying to find evidence for this and it doesn’t seem like NASA agrees with you: https://www.nasa.gov/feature/goddard/2020/what-will-solar-cycle-25-look-like-sun-prediction-model https://www.nasa.gov/feature/goddard/2020/what-will-solar-cy...
  - willmadden 5y ago
    NASA's past climate predictions have been consistently wrong. If you want evidence of this, and of the holes in the major models, please watch this video: https://www.youtube.com/watch?v=n-W76C0kkwc https://www.youtube.com/watch?v=n-W76C0kkwc "The further a society drifts from the truth, the more it will hate those that speak it." - George Orwell

dwheeler 5y ago

I agree, stopping at 1.5 C is extremely unlikely. You have to get worldwide agreement to do very hard things. I see little appetite for that. I also don't see any way to make it less hard, though if there is any hope that's where it lies.

benjohnson 5y ago
There's a lot of room for hope - I don't really care* global warming, and I'm getting solar on the house in five years because it's disturbingly cheap and will be driving an electric car because they're less maintenance. There's going to be a lot of moving away from oil - because refining sludge from the ground and transporting is expensive compared to the competition. Also... there's a heck of a lot of Nuclear Fusion research going on where I live. I wish them well! *I do care, but it's in the abstract. I kinda like not living in an ice-age. Normally, the land where my house sits is under 1.5 miles of ice.

cableshaft 5y ago

Plus there's the positive feedback loops, so even if that's the natural course we're on, it will lead to changes that will result in even further warming, i.e. no ice to reflect the suns heat, so we absorb more heat, and the methane released by the melting gas, amongst others (there's quite a few of them). From what I've been reading, it seems like if we get up to 2 degrees, the positive feedback loops would probably keep us going up to at least 4-5 degrees.

deleted 5y ago
[deleted]
fallingfrog 5y ago
That might be, but as far as I can tell that’s not considered a certain conclusion and I don’t consider myself qualified to judge how likely it is.
yread 5y ago
There are also lots of negative feedback loops - photosynthesis, cloud albedo, radiation, oceans, at some point human population might start shrinking...

willmadden 5y ago

We are heading into a grand solar minimum. My prediction is that the earth will be cooler in ten years. Check back in 2031 to see if I’m right. I’m far more worried about the magnetic pole shift and what that could mean about our sun.

kelp 5y ago
Was trying to find evidence for this and it doesn’t seem like NASA agrees with you: https://www.nasa.gov/feature/goddard/2020/what-will-solar-cycle-25-look-like-sun-prediction-model https://www.nasa.gov/feature/goddard/2020/what-will-solar-cy...
- willmadden 5y ago
  NASA's past climate predictions have been consistently wrong. If you want evidence of this, and of the holes in the major models, please watch this video: https://www.youtube.com/watch?v=n-W76C0kkwc https://www.youtube.com/watch?v=n-W76C0kkwc "The further a society drifts from the truth, the more it will hate those that speak it." - George Orwell