3) Cutting emissions will require a huge technological pushSo how do we cut emissions so drastically? First, the IPCC says that the world would have to triple or quadruple the amount of clean energy it uses. Second, we'd have to get dramatically more efficient at using energy in our homes, buildings, and cars.
Right now, about 17 percent of the world's energy is "low-carbon" — a little bit of wind and solar power, some nuclear power plants, a bunch of hydroelectric dams. Countries would have to ramp those technologies up dramatically — tripling or quadrupling that share.
That means two things. First, it's tough to rule out any particular technologies. For instance, plenty of environmentalists are opposed to nuclear power. But the IPCC estimates that the task of cutting emissions becomes 7 percent more costly if we shutter all our nuclear plants. Likewise, the technology to capture carbon emissions from coal plants and bury it underground is still in its infancy. If that technology fails, then cutting emissions becomes
twice as expensive.
if we rule out technologies like nuclear power, the task becomes much harder
Second, the IPCC notes that investment in fossil fuels — coal, oil, and natural gas — will have to decrease by 20 percent in the next few decades. After all, if we ramp up solar power, but coal expands even faster, that does no good for climate purposes. So the fossil-fuel industry has to take a hit.
Is this all doable? The IPCC thinks it's at least
technologically feasible. Whether it's politically realistic is another matter. The report suggests that countries could start taxing carbon emissions as way of pushing private companies to redirect their investments. So far, however, those policies have been slow to catch on — in the United States, a carbon tax is a non-starter in Congress.