1. Radical re-greening, of all deserts and polluted areas, with immediate development of CO2-neutral biomass are the only remedies, where no relief will serve. If we simply stopped all human emissions, we'd still suffer warming and climate change, since we've already cut forests, to a sufficient degree that will allow warming, and pine beetles and other pests are chipping in, with more chainsaw work, to cause nasty damage, to CO2 respiration. We'll need genetic engineering, or we'll fail, to get past climate change.
2. We will see a gradual improvement. We already have enough CO2 and CH4 out-gassing, from warming lands and waters, to hurtle us toward a PETM extinction, even if we re-green. But if we re-green, and we don't drop any nukes or screw up, with domestic nuclear power, we won't end up like most ocean species or 7 of 10 land species, by the end of the P-T extinction, the leading killer, of all geologic time.
3. CO2 and CH4 are shooting up, in concentration. We can only try, to maximize our leverage, and we can minimize damage, to decelerate the warming and climate change. But now that climate change is underway, we will get whacked, some. For instance, there is a 50-year lag, in re-surfacing, of ocean water, which absorbed the CO2, the last time it was at the surface. Of course, this is a circulation EFFECT, but in 50 years, the water at the surface now will have absorbed CO2, exchanged H2CO3 and CaCO3, and then it will come back up. So any oceanic acidification events 50 years from now will reflect, how CO2 was 400 ppm, in the atmosphere.
4. The better question is what will be the cost, of inaction? We will suffer a profound human die-off, at some point. So we will have to research, cleverly, and move, decisively. Of course, we can't do THAT, when idiots devised an invasion of Palestine, by the middle of the industrial revolution, to gratify their lust, for Crusades and for profiteering, at violating the US Constitution and statutes. We will have to SAVE and reapply funding, by cutting wars, of all types, especially the drug war, which prevents use of hemp, as a resource. War has a carbon footprint. We should cut religion, to save sectarian carbon consumption. And for sure, we have to quit supporting Israel, which is only looking for trouble, while the US supports its war machine and guarantees its oil supply. Got a problem, with religious states? Not until 1882, when the first Zionists migrated, from Britain, to Palestine, which started sectarian insurgencies, since 1886. Cut carbon consumption, get resources.
5. The US exports trouble and sequestered carbon consumption. It isn't Alien Global Warming, dude. The US has to quit borrowing, from China and Russia and Japan, to export the drug war, while keeping hemp out of the world energy market, despite having now drought-affected lands, which may have to grow switchgrass, since switchgrass will grow, on semi-arable land. Algae and switchgrass also have to enter the global energy market, and since the US is an importer of petroleum, the US has to man up and get out of the prison industry business, reapply funding, and show India and China the way, or leave them be. The BRICS nations are going to get their own bank, anyway, since the US is seen to be an anal, fading world superpower, burning out, rather than wisely fading away. See Henry Ford's 1941 hemp plastic car, on YouTube? Look at the vid, with a guy sledging the fender. You can't do THAT, to a Corvette, can you. Ford was making ethanol and plastic, from hemp, since the Model T. We can't catch up with Henry, if we have to keep feeding the PIGS.
The US does not get to pig the rest of the world, indefinitely. Remember, we are burning OUT. We are not fading away. Get a clue, about that. With a clue, we can win. Without, we lose.
