Last month, the Committee on Climate Change (CCC), official advisors to UK government, published a document called "UK climate action following the Paris Agreement" (CCC, 2016), summarised in the Guardian. It was significant because it acknowledged the need to invest in carbon dioxide removal (CDR) technologies with immediate effect.
The CCC claim that the UK will not reach the goal of net-zero emissions by 2100 at the latest due to reliance on aviation, agriculture and industry, all of which are emissions intensive. A target is already in place to reduce emissions by 80% from 1990 levels by 2050 as part of the Climate Change Act (2008) in domestic law, however, to account for the projected remaining percentage, CDR technology must compensate for remaining emissions (CCC, 2016). Is it really the only feasible way?
When studying and teaching energy policy, I have always taught and been taught not to put all of your eggs in one basket. Energy markets are volatile and require diversity in application to increase energy security. Whilst the CCC recommend that the UK should "vigorously pursue the measures required to deliver" the Agreement, there is little consideration of these other options. The decarbonisation of electricity and market incentives for zero-emissions vehicles and heating are mentioned, but recommendations are limited. For example, the key recommendation to increase the use of zero-emissions vehicles is to develop greater infrastructure to support them. I believe the CCC is missing the point of the problem here, which is that they remain unaffordable. State subsidies for development and production are also urgently needed.
I refer back to the example of China from my previous post: generous incentives have led to such a rapid increase in solar manufacturing that in 2014, China’s total installed capacity was 71% of total global operations (Mauthner, Weiss and Spörk-Dür, 2016). Cue increased output and reduced prices, increasing global feasibility of applying the technology. The reintroduction of the subsidies that were scrapped in the UK in early 2016 (Department of Energy and Climate Change, 2015) would help to boost production and reduce costs of any technologies that we need to develop urgently to meet the net-zero target.
The CDR technologies proposed for investment are carbon capture storage (CCS) and air capture and storage (CCC, 2016). CDR is regarded as necessary because CO2 absorbs long-wave radiation that would have been reflected back into space, which is then reemitted as heat. Removal of CO2 will therefore reduce the amount of long-wave absorption, limiting temperature increase. CDR must be deployed on a scale to match the energy system releasing CO2 into the atmosphere (Caldeira et al., 2013), showing that it requires global participation to be successful. Is it the main answer to the UK's problems?
Carbon Capture and Storage (CCS)
CCS is in the early stages of development, but the IPCC (2005) believe that it has great potential. CCS plants are normally attached to point sources of emissions (e.g. a power plant) to capture emissions more effectively. It could reduce emissions of a typical power plant by 80 to 90%. However, feasibility is uncertain because no commercial projects currently exist. Furthermore, long-term storage security in geological formations is unknown. There is risk of CO2 leaking and widespread impacts could alter oceanic pH (Phelps et al., 2015). Although, acidification rates would be slower than under unmitigated CO2 emissions, indicating that CCS is investment-worthy.
If 3% of terrestrial space on earth was assigned to CCS projects, 1 GtCO2e/yr could be removed (Caldeira et al., 2013). The Paris Agreement states that annual emissions must reduce to 40 GtCO2e to meet the two-degree limit (CCC, 2016). This shows that CCS is limited for effective sequestration alone and must be implemented alongside other solutions. CCS could be easily assigned to power plants in the UK, and the UK currently has a policy in place to ensure that all new coal-fired power stations are built with CCS some part of the infrastructure (CCSA, 2016).
Direct air capture and storage
Similarly, air capture and storage is also in need of development as the feasibility is uncertain. It is a similar approach to CCS, except it is independent of any current energy infrastructure. This means that it is likely to be less expensive than CCS (Caldeira et al., 2013). Progressive research has already taken place, such as the idea of using carbon-absorbing materials like porous metal-organic frameworks (Ma and Zhou, 2010), or injecting CO2 into basalt underground that forms solid rock within two years (McGrail et al., 2016). If this study proves repeatable, the risk of CO2 leakage would be significantly reduced and would help to balance the carbon cycle with greater terrestrial uptake.
The alternatives:
Renewables, of course! The UK is rife with potential for wind, solar and tidal power to name a few. Nuclear power (whatever your stance) is remaining part of our energy policy with the announcement of the construction of Hinckley Point C in September 2016. Bring back those state subsidies!
And what of solar radiation management as an alternative? It is clear from my investigation into space-based schemes last week that it will not solve the root problem of continued CO2 emissions. It is too expensive an approach to buy us time for figuring out an effective CDR solution in such a small time frame. Of all SRM techniques, aerosols may well serve as the most time and cost-effective approach (Caldeira et al., 2013), but we'll find out more about those later...
Overall, the CCC are correct that CDR methods need urgent investment and deployment, but focus should not be shifted to CDR alone. It definitely shouldn't be used as means to justify inadequate emissions reductions. Investments in renewables and energy efficiency are also imperative.
No comments:
Post a Comment