Comment by palata
> These can be measured for averages. Lots of cars with one person in them
Sure, but the point should be that we should strive to share cars, not that it's okay to take the plane! Especially given the second argument which is that you don't drive 1000km every time you take your car. The footprint per km is not enough: when you take the plane you typically go much further!
> Probably, yes; last year passed the threshold
That, plus the IPCC scenario that keeps us under 1.5C says that in a few decades, not only we won't be extracting any carbon anymore, but we will be pumping carbon underground faster than we are extracting it now! And that's with the IPCC models which tend to be optimistic (we measure that every year)!
> 14 because it would take 14 years for the exponential — seen for the last 30 years — for PV to replace all forms of power consumption
And you would have to take into account that PV today entirely relies on oil. We are going towards a world with less and less oil, and we don't know how it will impact our capacity of production for PVs. But probably it won't help.
> In so far as your bracket, sure; but there's a huge gap in what equipment you would need.
Sure. It was a quick way to say that the combination of humidity and temperature will be such that sweating won't help humans regulate their temperature. And when we can't regulate our temperature, we die. By any account, this means that billions of people will have to relocate, which means global wars (with entire countries moving with their entire armies).
Now of course that would be infinitely better than trying to live on Mars, which is why it is preposterous to even consider Mars.
> but we will be pumping carbon underground faster than we are extracting it now!
While I know about "we need to sequester carbon", I thought the assumption was more for the last 10% (which makes sense, last 10% of anything is often expensive), not >100% of current?
> And that's with the IPCC models which tend to be optimistic (we measure that every year)!
Indeed, unfortunately.
> entirely relies on oil
I don't believe "relies on" is correct: while I would agree that e.g. plastics are made from oil, that oil currently powers some of the energy generation capacity used for the manufacturing plants that make the panels, that shipping and air transport are at present almost entirely oil-based, these are not "entirely relies on oil", they are "the economy in which they emerged happens to have been built on oil".
This is importantly different, because as renewable energy ramps up, the CO2 emissions resulting from each of these steps also goes down — even for the plastic, as the carbon in the oil itself is much more valuable as plastic than as a fuel waste product.
> By any account, this means that billions of people will have to relocate, which means global wars (with entire countries moving with their entire armies).
Aye.
Lots of room for massive disasters there, even if it were not for the fact that at least one affected area already has nukes.