Given that global warming will cause the global economy to contract one way or another within the next 100 years (either we willingly contract to soften the blow, or keep going and producing more greenhouse gases until a massive crash), I really don't think this is the right time to think in these terms.
I believe the latest IPCC report on climate change expected outcome even for the worst scenario had a noticeable decrease in the rate of growth of the global economy - not a contraction, just slower growth. We do not seem to be on track for a global contraction of economy, not even in the face of climate change.
And economic growth is already (though not that recently) somewhat decoupled from growth in greenhouse gas emission, so any actions taken to reduce climate consequences do not have to be at the cost of stopping global growth, much less intentionally contracting global economy; and in fact the only actions likely to be taken in practice are those which don't stop economic growth - the general population, especially those in poorer countries (even those directly harmed by climate change) will not accept that cost.
> I believe the latest IPCC report on climate change expected outcome even for the worst scenario had a noticeable decrease in the rate of growth of the global economy - not a contraction, just slower growth. We do not seem to be on track for a global contraction of economy, not even in the face of climate change.
The reports do talk about economic contraction after the year 2050 if we don't reach the 2 C temperature goals. They also don't model the likely resource wars that will happen if large parts of Bangladesh, India, Pakistan, Mexico etc will become uninhabitable by the end of the century, due to rising temperatures and water levels.
> And economic growth is already (though not that recently) somewhat decoupled from growth in greenhouse gas emission, so any actions taken to reduce climate consequences do not have to be at the cost of stopping global growth, much less intentionally contracting global economy
The IPCC reports says that GHG emissions increase is mostly proportional to GDP increase throughout all regions, with a significant, though smaller, contribution from population increase. It's also notable that GHG emissions continue to increase - we are not anywhere near a plan for net 0, and nothing suggests so far that we are even likely to start reducing GHG emissions, globally or even in any particular region.
Why can't technological advancement stave off climate change damage? Why cant renewables replace fossil fuels, and continue human expansion? Why can't space exploration and settlement be where the future growth occurs?
> Why can't technological advancement stave off climate change damage?
What technology in particular could stop the oceans from rising and swallowing much of today's southern coastlines, and what technology in particular could reduce wet-bulb temperatures across most of the world's south below 50C, the point where healthy adult humans with access to infinite water will die of heat stroke?
> Why cant renewables replace fossil fuels, and continue human expansion?
Because renewables are not reliable, rely on rare metals, and can't replace the huge amount of energy produced by oil. Someone was making a calculation the other day that replacing the entire fleet of vehicles in the USA with electrical cars would require doubling the electricity production of the states. Do you really think that's possible in 50 years, while also replacing all gas and coal plants with renewables?
Also, there are huge areas of industry that use oil or natural gas for many reasons other than energy - plastics, synthesizing NH3 for fertilizer and other uses.
> Why can't space exploration and settlement be where the future growth occurs?
Because we are nowhere near having the technological advancement needed for space settlement that would do anything other than cost resources. Perhaps there is some small chance of having a research base on Mars or the Moon within the next 50 years, akin to the ISS, but ideas of "colonizing Mars" are beyond sci-fi at this point. We couldn't even colonize Antarctica with current technology.
Besides, there's nothing on Mars that we don't have much more easily accessible on Earth - no rare metals, no crop fields, no spices, no native workers we could import as slaves, no cotton or anything that could even conceivably resemble the existing reasons for colonization. And lest you think anything else, there is nothing we can conceivably do to the Earth that would make it anywhere near as inhospitable as Mars. Even the worse possible consequences of a Nuclear War would not leave Earth as radioactive, poisonous, cold, or otherwise inhospitable as Mars is today.
10 years ago, no one would predict that the cost of solar would drop by 80%-90%. There's still a lot of untapped potential in other forms of renewables too. The current bottleneck of batteries might be solved, i'm sure, in the near future.
There's a lot of pessimism among the media. I, for one, am hopeful.
We are far from the limits of thermodynamics. You'd have to wait till nearer to the heat death of the universe for that to have an effect on the economy.
Only for gasoline engines. And the efficiency limit isn't the limit of possible sources of energy for work. Future engines could be electric, and the power source could be fusion.
With electric vehicles, you reach the problem of fuel weight. There is simply no realistic battery chemistry that comes close to the specific energy of oil-based fuels (J/kg). Gasoline (oxidation) is at 46MJ/kg, while a Li-Ion battery has at best ~0.9MJ/kg or so. Even a Zn-Air battery has a theoretical maximum specific energy of ~5MJ/kg, an order of magnitude less than gasoline oxidation.
You need huge increases in engine efficiency to make up for the extra weight. This is the reason why there are no electric cargo transporters so far - you may not care so much if your personal car is heavier, but a truck or cargo ship definitely cares.
Edit: Perhaps a car-sized fusion power generator is possible in some far future technology, but we are enormously far from that. At a minimum, it would require achieving fusion with materials that don't generate neutrons as a by-product, as those are enormously radioactive, and very hard to shield (read: have to be bulky). Things like deuterium-deuterium fusion are far out of reach at the moment, requiring much higher temperatures than we can currently achieve.
fusion takes is to a straight line to exceeding capacity of the planet to radiate waste heat fast enough to keep it habitable. free energy is self destruction. still better than fossil fuels, though.
electric engines require batteries and batteries are super duper enviromentally expensive to make at scales needed right now, let alone the 10y forward predictions.
Global warming is extremely likely to lead to large areas that are well populated today becoming uninhabitable in the next 100 years - either through oceans rising or through extreme heat. This will likely lead to huge migrant crises - not hundreds of thousands, but tens of millions leaving places like Bangladesh. This in turn is very likely to lead to wars and other forms of extreme events. A world at war is very likely to stop growing economically, and we may not be able to require from a nuclear war the way we did after WW2.
