US CO2 emissions (according to EPA) are 37% electricity, 31% transportation, 15% industry, 10% residential and commercial (I think that means buildings). 6 per cent from other sources.
How can expertise be used to reduce all of these?
ELECTRICITY: decarbonised electricity options widely exist (wind, solar, coal + CCS). They are all more expensive, but the high price is more of a political problem (how can politicians ask people to pay more for electricity) rather than a society problem (can people afford it). The problem is increased by lack of a market mechanism to make it investable – (there are many attempts but none really working). Also solar + wind have an intermittency problem, and electricity storage hasn’t been solved (although there are many ideas). So coal + CCS looks like a ‘low hanging fruit’.
TRANSPORTATION: is perhaps the toughest carbon problem to fix. The easiest way is if people stop travelling but that’s very hard for a politician to acheive and of course not something the public wants. Adding carbon fees to travel costs as a disincentive is a possibility but perhaps not a good one. Electric transportation is a possibility, but is only low carbon if there is decarbonised electricity (see above). Hydrogen power is another possibility, but the hydrogen needs to be created from gas or coal with carbon capture, so unlikely to happen until carbon capture happens. (Or it can be created from renewables).
INDUSTRY: The problem with industrial emissions is that most industry can easily move, and carbon regulations are unlikely to happen globally for a while, if at all. So adding cost to industry in a rich country drives the industry to move and emissions stay the same. There is some wiggle room perhaps. Another possibility is if the buyers of goods are required to ‘pay’ for the carbon somehow (or at least, be more aware of it) – then it doesn’t matter which country the goods are actually made in. If decarbonised electricity was available then that makes it much easier for industry to be decarbonised.
RESIDENTIAL AND COMMERCIAL BUILDINGS – technology largely exists to make buildings zero carbon, although there could be some penalty on comfort and cost – smaller windows, thicker walls, less airconditioning in summer or heating in winter. There are big advances in this technology happening all the time. Again, decarbonised electricity can be used for heating and cooling.
One conclusion here is that decarbonising electricity really is a massive step forward in reducing all CO2 emissions. We’re moving as fast as we can (arguably) in renewables. We’re not moving as fast as we can for coal + carbon capture.