www.ecn.nl

Offshore CCS and Ocean Acidification Bob van der Zwaan

ECN, Policy Studies, Amsterdam

Johns Hopkins University, SAIS, Bologna

University of Amsterdam, Faculty of Science

Work with Reyer Gerlagh (Tilburg University)

IEW, Cork , 1-3 June 2016

Onshore vs. offshore CCS

• CCS has for two decades been a promising climate change mitigation technology, but still has not been deployed on any meaningful scale.

• Among the reasons is public fear over environmental and health impacts of CO2 storage, and over potential leakage of CO2.

• Storing CO2 under the seabed moves this option away from inhabited areas and could thus take away some opposition towards CCS.

• Offshore CCS could also address concerns over the climatic impacts of CO2 seepage, as the ocean could function as buffer.

• Question: What could be the relative roles of on- and offshore CCS, and what could be the impacts in terms of temperature increase and ocean acidification of CO2 leakage?

New model

• We built a global top-down IAM, called OCEAN, with which we performed cost-benefit analysis of climate change mitigation.

• Several new features w.r.t. our earlier work with DEMETER, e.g. because both on- and offshore CCS options are modelled.

• We did Monte Carlo analysis so as to investigate the probabilistics w.r.t. many of our parameter assumptions.

CO2 leakage

• Recent geological studies provide evidence that to date CO2 has been safely stored under the seabed.

• Leakage for individual offshore CCS operations seems technically unlikely, if storage sites are well chosen, managed and monitored.

• We argue, however, that on a global long-term scale for thousands of storage sites, leakage could occur in certain cases or countries for e.g. economic, institutional, legal or safety-cultural reasons.

• Hence, the relevance, and even necessity, to perform our study.

ECO2 project

• Large FP7 integrating collaborative project funded by the European Commission (27 partners from 9 EU countries, 2011-2015).

• Full name of the project, coordinated by GEOMAR in Kiel, Germany: “Sub-seabed CO2 Storage: Impact on Marine Ecosystems”.

• Mostly a natural scientific endeavor, involving notably the geophysical, hydrological, marine and biological sciences.

• Project also included an economic component, inspecting costs and benefits from a local (IfW) and global (ECN) perspective.

Objectives

• Investigate likelihood of leakage from sub-seabed storage sites

• Study leakage effects on benthic organisms and marine ecosystems

• Assess the risks of sub-seabed CO2 storage from a broad perspective

• Develop a monitoring strategy using cutting-edge techniques

• Define guidelines for best environmental practices in implementation and management of sub-seabed storage sites

OCEAN model: main features

• OCEAN is an optimal growth IAM based on welfare maximization for global consumption aggregated over time.

• Production uses labor and capital as inputs, and two energy options (fossil-based and non-fossil) as an intermediate.

• CO2 emissions can be reduced through non-fossil energy use or CCS applied to fossil-based energy.

• Two types of CCS: sub-land and sub-seabed (on- and offshore), with different leakage profiles and associated economic costs.

• Reducing emissions is costly, but benefits are gained from avoiding damage costs incurred to the atmosphere and ocean.

• Different from DEMETER also since no endogenous learning, plus better climate module (less CO2 uptake as ocean saturates: pH ↓).

OCEAN model: main assumptions

Many assumptions need to be made, which we do with lognormal uncertainty ranges (with 2.5%-median-97.5% probability levels):

• Offshore CCS is significantly more expensive than onshore CCS: 25-75-225 €/tCO2 resp. 17-50-150 €/tCO2.

• Majority of CO2 stored geologically will stay underground forever, hence share of sites with entirely immobilized CO2 is: 40-70-75%.

• For unsafe storage sites, offshore leakage is potentially higher than onshore leakage: 0.1-0.5-2.4 %/yr resp. 0.1-0.3-1.0 %/yr.

• Leakage into the atmosphere (3°C) yields more (tangible) damages than the ocean (ΔpH ~ 550 ppmv): 0.5-2-8% resp. 0.01-0.1-1% GDP .

• “Standard” assumptions on population and GDP growth, as well as BAU energy and non-energy related CO2 emissions.

Annual CO2 emissions

Atmospheric CO2 concentration

Global temperature increase

Ocean acidification

Annual storage of CO2 onshore

Annual storage of CO2 offshore

CCS share versus costs

Offshore CCS share versus cost Δ

Main conclusion

• Even under ‰/yr leakage for CCS, onshore and offshore CCS should probably – on economic grounds at least – account for anywhere between 20% and 80% of all future CO2 abatement efforts.

• Our work just got accepted (open access): van der Zwaan, B.C.C. and R. Gerlagh, “Offshore CCS and Ocean Acidification: A Global Long-Term Probabilistic Cost-Benefit Analysis of Climate Change Mitigation”, Climatic Change, 2016, now online available: DOI 10.1007/s10584-016-1674-5.

Onshore versus offshore CCS

CO2 emissions versus CO2 price