In contrast, the dispersed and mobile sectors typically involve many small sources of emissions, owned by millions of individuals who may not have ready access to funds for investment and are less easily addressed by regulation.
These sectors may only be able to make deep reductions in emissions through changes to the energy carriers used to supply their buildings or vehicles – for example, substitution of petrol in cars by electricity or hydrogen (as long as such energy carriers have been made without CO 2 emissions). Such changes would require major changes in the fuel distribution system as well as in vehicle technology. Necessarily, making changes in millions of fuel-using systems would take longer and be more difficult to do than changes to a few thousand plants in the industrial sectors.
This discussion will now focus on tackling the centralised and major industrial sources of emissions.