Development of scientific and geopolitical criteria to rank - - PowerPoint PPT Presentation

Development of scientific and geopolitical criteria to rank geoengineering schemes

• My background
• Do we know enough to rank schemes?
• Ranking – based on scientific issues
• Ranking – using geopolitical concerns
• Multi-stranded approach – R&D and

international governance frameworks

Philip Boyd

My background – large scale scientific experiments Into ocean iron enrichment

Why now? Time is short

Avoiding the risks of dangerous climate change requires that global greenhouse gas emissions peak within the next fifteen years are halved relative to 1990 by 2050, and then decline to less than 10 Gigatonnes (GT) of emissions (1 tonne per capita). Lord Stern 2008

Years Design ranking scheme & conduct initial ranking Research Technological advances Test-beds and trials Scientific issues Geopolitical concerns International governance & Legislative structures Implementation decisions

Time is short

Proliferation of schemes

>15 Years of press coverage

• n Geo-engineering but no science

SO Do we know enough to rank schemes?

Ranking geo-engineering schemes

Boyd (2008) Nature Geosciences

Rationale – historical precedents

“This can be achieved by burning S2

• r H2

S, carried into the stratosphere

• n balloons and by artillery guns to produce SO2

.” “In the stratosphere, SO2 is converted into sub-micrometer sulfate

• particles. This has been observed in volcanic eruptions e.g., Mount

Pinatubo which injected some 10 Tg S, initially as SO2 , into the tropical stratosphere” “This cooled the earth’s surface on average by 0.5 ◦C in the year following the eruption.”

“The end result of this field experiment was rapid delivery (<2 h for a 300 m transit) of deep water to the surface

• cean followed by catastrophic failure
• f pump materials under the dynamic

stresses of the oceanic environment.” White et al. (2009) Ocean Tech.

Rationale - Degree of testing

2 $ a tonne for ocean fertilisation

“200 boats, 8.1 M tons of iron, 16 M square miles of HNLC ocean – 8 Gigatons of CO2 each year” “Dumping Iron”, Michael Markels Interview in Wired, November 2000

Affordability - initial estimate

50-300 $ a tonne

Affordability - including side-effects

C ost ($ U S per Tonn e C seq uestered)

50 100 150 200 250 300 350

Reference

1 2 3 4 5 6 7

Markels

• S. Ocean phytoplankton

SERIES mixed layer Fe:C NABE bloom export SERIES export 50m SERIES export below 150m Boyd (2008)

• Mar. Ecol. Prog. Ser.

Safety - side-effects The Earth System is a complex circuit diagram Pinatubo also caused: Drought – hydrological cycle Ozone depletion Acid rain Aerosols into the ocean

Trenberth & Dai (2007) GRL

Side-effects – the Rumsfeld suite of permutations

Thingstad et al. (2005)

Safety - System complexity BIO-geoengineering is most complex

Brewer et al. (1999) Jickells et al. (2005)

Safety - Verification

No schemes have been trialled or tested System complexity will impact verification

Biogeochemical > geochemical > physico-chemical

0.5 1.0 1.5

Fe (mol/kg ice)

180 200 220 240 260 280 300

[CO2] (ppmv)

20 40 60 80 100 120 140 160

Age (1000 yr)

Iron CO2

Rapidity - Mitigation rate

Martin (1990) Socolow & Pacala (2004)

Vaclav Smil

Rapidity - Emergency stop

Ranking geo-engineering schemes

Boyd (2008) Nature Geosciences

All modelling experiments to date suggest that the deleterious impacts of climate change will be unevenly spread across the planet

GEOPOLITICS & GEO-ENGINEERING

Boyd & Doney (2002) GRL

Also it is recognised that both the beneficial & detrimental effects, resulting from geoengineering will also be unequally distributed.

Robock et al. (2009) GRL

“In addition to the impacts of climate change, geoengineering may concurrently diminish resource availability at the regional scale, increasing the potential for conflict between nations over resources.” “Second, the attribution of the cause(s) of such diminished resources will be difficult and contentious.” GEOPOLITICAL IMPLICATIONS

NODC

Boyd (in press) Nature Geosciences

Large scale ocean fertilisation will probably result in the consumption of nutrients destined for other ocean basins – raising issues of SCALE & ATTRIBUTION

Sarmiento et al. (2004) Nature

Detection & attribution of the impact of a geoengineering scheme will be confounded by: concurrent emissions & climate change Other geoengineering schemes Altered C sinks, unanticipated feedbacks, climate variability

Le Quere et al. (2007) Raupach et al. (2006)

Its not only the scale of geoengineering schemes – but also dispersal – implications for provenance

Animation courtesy F. Chai (U. Maine)

Participation & replication Stratospheric S injection Artificial trees

Conflict avoidance – loss of resources such as ocean or land productivity

Science 2008

Models indicate that sustained ocean iron fertilization can also lead to anoxia

Ranking geo-engineering schemes

Boyd (2008) Nature Geosciences

Years Design ranking scheme & conduct initial ranking Research Technological advances Test-beds and trials Scientific issues Geopolitical concerns International governance & Legislative structures Implementation decisions

Time is short