"The world must cut CO2 emissions to zero by 2070 at the latest to keep global warming below dangerous levels and prevent a global catastrophe, the UN warns."
At first blush, 2070 sounds far away -- 50+ years to figure out how to get negative emissions (or carbon dioxide removal, "CDR") technology should be no problem... right?
Unfortunately, this isn't as much time as it sounds. For one, it turns out that energy technologies have historically taken a long time to reach commercial maturity. In "Past and prospective energy transitions: Insights from history," energy history experts Roger Fouquet and Peter J.G. Pearson demonstrate that past energy transitions have taken decades at the least to play out:
While advances in modern technology have shortened development cycles for many products considerably, there are a number of factors suggesting that CDR development might progress more similarly to historical technologies: the non-regulatory demand for CO2 is small compared to that for energy, there are few network effects or natural monopolies associated with many forms of carbon removal, and regulatory markets necessary to support CDR development have been anemic at best. So while it is certainly possible to develop the CDR field quickly, history and current market conditions suggest that such rapid development isn't likely to happen of its own accord.
In addition, it would likely be beneficial to have viable CDR technologies well before 2070. Not only will they be needed sooner if we are slower to decarbonize than the IPCC projects is necessary, but they can also make the decarbonization process more cost effective:
The GHG abatement curve prepared by the consultancy McKinsey, above, shows that cost-effective CDR technologies (highlighted in orange) can help reduce the overall cost of decarbonization. The sooner we have viable, cost-effective CDR technologies, the less painful preventing climate change will be.
In conclusion, there is no time to wait to start developing CDR technologies. We need to start investing in basic science, applied R&D, and the market standards and structures for a wide range for CDR approaches to ensure that, when CDR technologies are need, we have them at the ready.