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FISOC: Framework for Ice Sheet – Ocean Coupling
ESMF regridding options include unstructed meshes
ESMF example grids
Elmer/Ice example mesh
Solar Radiation Management: Potential, Risks and Outlook
J.C. Moore
Conserving the Planet
地球工程机理示意图
Royal Society Report, 2009
John Sheperd
Ocean chemistry projection using a coupled climate-carbon cycle model
0 1 2 3 4
Saturation state of calcium carbonate
(Ωaragonite)More acidic
5
Cao and Caldeira, 2008
Less acidic
Climate change is felt differently in the developing world• Impacts are already happening
• For some it is already an existential threat
• Many have a far different view of man and nature than the Western one
• Surveys show they are more open to any solution –they know man caused this problem, they hope man can fix it
Tropical circulation: Hadley cell
Guo et al., 2018
Changes under SRM
Changes under GHG
Tropical circulation: Walker cell
Guo et al., 2018
Tropical circulation: Walker cell
Guo et al., 2018
Changes under SRM
Changes under GHG
Hincket et al., PNAS 2016
21st century Global sea level rise will affect hundreds of millions of people on our planet. World Bank, 2007
- 500 million people for 1 m rise (USGS)
Flooding due to rising global sea level
Cost of 1.8 m coastal flooding as a 95% limit, (Jevrejava 2016) = €50 trillion/year by 2100Coastal protection cost =€15-70 billion/year (Hinckel 2014)
Antarctic Mass Loss
Pritchard et al., 2009
The soft underbelly of Antarctica
The future
The Greenland ice sheet is expected lose at least 90%
of its current volume if ice sheet summer temperatures
warm by around 1.8C above pre-industrial
Why is happening?
Warming temperatures
Air and ocean in Greenland
Ocean warming in Antarctica
PLUS Inherent instability of parts of the ice sheet
Risks from SRM
Changes from present climate- All simulations show much smaller
changes under SRM than under greenhouse gas forcing alone.
Because most changes depend on changes in temperatures – even precipitation patterns.
Risks from SRM
Changes due to new processes- SRM by aerosol injection would create new
chemistry in the stratosphere. We know bad things happened with ozone due to CFCs in 1980s
Would similar things happen again?Climate models were much cruder in 1980s than now. But there is a lack of physics knowledge about aerosols in the stratosphere
Risks from SRM
Moral hazard- Would SRM provide an opportunity to
neglect mitigation?
Evidence is mixed – reverse moral hazard may also exist
Risks from SRM
Governance- How to decide what level intervention to
make?
As an engineering problem we could decide sophisticated global temperature regimes –matching much of present day variations (N-S, equator-Pole, mean T)Would states agree on an optimum temperature? – to preserve the cryosphere they would have to
What could SRM achieve?
Huge injections needed to offset RCP8.5
Tilmes et al BAMS 2018
What could SRM achieve?
More likely limited to 1-2C decreases
To avoid overshoot it would need to be done for 150 years
Need an exit strategy
John Sheperd
Can anything else be done?
• In some cases Targeted Geoengineering might provide partial solutions
• Pleistocene Park in Siberia for permafrost
• Ice911 for sea ice
• Glacier geoengineering for sea level
Is it scientific?
Ethical obligation: Egalitarian &Transgenerational
Failsafe