CO2 Capture and Storage
10. Conclusion: the future of CO2 capture and storage
- 10.1 What knowledge gaps remain?
- 10.2 How much could CO2 capture and storage contribute to climate change mitigation?
10.1 What knowledge gaps remain?
capture and storage is technologically feasible and could play a
significant role in reducing
greenhouse gas emissions
over the course of this century. Although parts of the
technology are tried and tested, increased knowledge,
experience, and reduced uncertainty about specific aspects of
CO2 capture and storage would be important to enable
its large scale deployment.
First, the technology needs to mature further. While the
individual components of
capture and storage are well developed, they still need to be
integrated into full scale projects in the electricity sector.
Such projects would demonstrate whether the technology works
when fully scaled up, thus increasing knowledge and experience.
More studies are needed to analyse and reduce the costs and
estimate the potential capacity of suitable geological storage
sites. Regarding other forms of storage, pilot scale experiments
on mineral carbonation are
needed to reduce costs and net energy requirements. In addition,
studies concerning the ecological impact of CO2 in
the deep ocean are required.
The adequate legal and regulatory environment also needs to be
further developed. This must include agreed methods for
estimating and reporting the amount of
avoided by CO2 capture and storage as well as the
amounts that may leak over the longer term. Long-term
liabilities of geological storage and potential legal
constraints on storage in the marine environment need to be
taken into account.
Other issues to be resolved include the potential for transfer
and diffusion of CO2 capture and storage
technologies, opportunities for developing countries to exploit
them, application of these technologies to
biomass sources of
CO2, and the potential interaction between investment
in CO2 capture and storage and other mitigation
10.2 How much could CO2 capture and storage contribute to climate change mitigation?
If knowledge gaps are filled and various conditions are met,
capture and storage systems could be deployed on a large scale
within a few decades as long as an explicit policy is put into
place to substantially limit
greenhouse gas emissions to
A particularly critical issue remains that of incentives. If a
“carbon price” is established for each unit of
greenhouse gas emissions,
this could create incentives to invest in processes which emit
less greenhouse gases. CO2 capture and storage
systems are only likely to be widely adopted for power
generation – the sector with by far the greatest potential –
when the price of emitting a tonne of CO2 exceeds
25–30 US$ (in 2002 dollars) over the lifetime of the project. A
price on emitting CO2 can only result from policy
decisions for limiting CO2 emissions. CO2
capture and storage systems would be competitive with other
large-scale mitigation options such as nuclear power and
renewable energy technologies.
As part of a portfolio of actions to mitigate
capture and storage could reduce the cost of stabilizing the
concentration of greenhouse gases in the
atmosphere by 30% or more.
Most scenarios for
achieving such stabilisation at least cost estimate that the
amount of CO2 that could potentially be stored
underground and in oceans during this century ranges between 220
and 2 200 GtCO2. To achieve this potential, several
hundreds or thousands of CO2 capture and storage
systems would be required worldwide over the next century, each
capturing some 1 to 5 MtCO2 per year. Such systems
would need to be built in significant numbers in the first half
of the century with the majority of them being built in the
In the absence of measures for limiting
emissions, there would only be small, niche opportunities for
carbon capture and storage technologies to deploy with a maximum
potential of about 360 MtCO2 per year. Such
opportunities alone are unlikely to contribute significantly to
the mitigation of
climate change unless
extended to the power sector.
Concerning long term leakage from storage, there must be an
upper limit to the amount of leakage that can take place if
capture and storage is to be acceptable as a
climate change mitigation
measure. A fraction retained on the order of 90–99% for 100
years or 60–95% for 500 years could still make such impermanent
storage valuable for the mitigation of climate change.
The consensus of the literature shows that
capture and storage could be an important component of the broad
portfolio of policies and technologies that will be needed if
climate change is to be
successfully addressed at least cost.