https://phys.org/news/2018-07-decarbonising-emissions-difficult-impossible.html

But just over a quarter of emissions from fossil fuels and industry are significantly more difficult to decarbonise than the rest – and emissions from these sectors are growing. In light of this the authors say more focussed research and development may be required to bring down costs.

Co-author Professor Paul Fennell, of Imperial's Department of Chemical Engineering, explains that some emissions may require more effort to bring down than others. He argues we should also focus on, but not limit ourselves to, providing clean, low-cost energy and new fuels, as well as using carbon capture to allow future air travel, cement and steel, and trucks to operate.