a framework for possible geoengineering impacts dr nem vaughan tyndall centre for climate change...
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A framework for possible geoengineering impacts
Dr Nem VaughanTyndall Centre for Climate Change Research
University of East Anglia
[email protected] January 2011
www.iagp.ac.uk
Outline
• Geoengineering – carbon and solar
• Impacts – direct and indirect– local to global– traceable, attributable
• What we do and don’t know about the impact of geoengineering on ecosystems
Slide 2
Outline
• Geoengineering – carbon and solar
• Impacts – direct and indirect– local to global– traceable, attributable
• What we do and don’t know about the impact of geoengineering on ecosystems
Slide 2
Outline
• Geoengineering – carbon and solar
• Impacts – direct and indirect– local to global– traceable, attributable
• What we do and don’t know about the impact of geoengineering on ecosystems
Slide 2
Types of geoengineeringSlide 3
Vaughan & Lenton (in press) Climatic Change
Carbon geoengineeringSlide 4
Capture
Storage
Carbon removal
LandOcean
LandOcean Geology
Novel
Carbon geoengineeringSlide 4
Capture
Storage
Carbon removal
LandOcean
LandOcean Geology
Novel
Carbon geoengineeringSlide 4
Capture
Storage
Carbon removal
LandOcean
LandOcean Geology
Novel
Solar geoengineeringSlide 5
Surface
Reflective approaches
Troposphere
Stratosphere
Space
Land Ocean
Solar geoengineeringSlide 5
Surface
Reflective approaches
Troposphere
Stratosphere
Space
Land Ocean
Impacts of carbon geoengineering
• Addresses excess of CO2 in the atmosphere
• Slow to impact, but lasting
• Scale of intervention • human cumulative emissions: 354 PgC • afforestation (300PgC)• Competition with other land use/space• water, fertiliser, fast growing species, monoculture?
• Storage viability• terrestrial, ocean or geology
• Very rapid removal may cause natural sinks to release carbon
Slide 6
Impacts of carbon geoengineering
• Addresses excess of CO2 in the atmosphere
• Slow to impact, but lasting
• Scale of intervention • human cumulative emissions: 354 PgC • afforestation (300PgC)• Competition with other land use/space• water, fertiliser, fast growing species, monoculture?
• Storage viability• terrestrial, ocean or geology
• Very rapid removal may cause natural sinks to release carbon
Slide 6
Impacts of carbon geoengineering
• Addresses excess of CO2 in the atmosphere
• Slow to impact, but lasting
• Scale of intervention • human cumulative emissions: 354 PgC • afforestation (300PgC)• Competition with other land use/space• water, fertiliser, fast growing species, monoculture?
• Storage viability• terrestrial, ocean or geology
• Very rapid removal may cause natural sinks to release carbon
Slide 6
Impacts of carbon geoengineering
• Addresses excess of CO2 in the atmosphere
• Slow to impact, but lasting
• Scale of intervention • human cumulative emissions: 354 PgC • afforestation (300PgC)• Competition with other land use/space• water, fertiliser, fast growing species, monoculture?
• Storage viability• terrestrial, ocean or geology
• Very rapid removal may cause natural sinks to release carbon
Slide 6
Impacts of carbon geoengineering
• Addresses excess of CO2 in the atmosphere
• Slow to impact, but lasting
• Scale of intervention • human cumulative emissions: 354 PgC • afforestation (300PgC)• Competition with other land use/space• water, fertiliser, fast growing species, monoculture?
• Storage viability• terrestrial, ocean or geology
• Very rapid removal may cause natural sinks to release carbon
Slide 6
Impacts of solar geoengineering
• potentially quick to change temperature• addresses a symptom (not the cause)
• rate of change – potentially quite fast (on and off)
• long term commitment?• ocean acidification– untreated or possible worsened
• decreased global precipitation– evident in some modelling results
• residual warming– i.e. still warmer in poles
Slide 7
Impacts of solar geoengineering
• potentially quick to change temperature• addresses a symptom (not the cause)
• rate of change – potentially quite fast (on and off)
• long term commitment?• ocean acidification– untreated or possible worsened
• decreased global precipitation– evident in some modelling results
• residual warming– i.e. still warmer in poles
Slide 7
Impacts of solar geoengineering
• potentially quick to change temperature• addresses a symptom (not the cause)
• rate of change – potentially quite fast (on and off)
• long term commitment?• ocean acidification– untreated or possible worsened
• decreased global precipitation– evident in some modelling results
• residual warming– i.e. still warmer in poles
Slide 7
Impacts of solar geoengineering
• potentially quick to change temperature• addresses a symptom (not the cause)
• rate of change – potentially quite fast (on and off)
• long term commitment?• ocean acidification– untreated or possible worsened
• decreased global precipitation– evident in some modelling results
• residual warming– i.e. still warmer in poles
Slide 7
Impacts of solar geoengineering
• potentially quick to change temperature• addresses a symptom (not the cause)
• rate of change – potentially quite fast (on and off)
• long term commitment?• ocean acidification– untreated or possible worsened
• decreased global precipitation– evident in some modelling results
• residual warming– i.e. still warmer in poles
Slide 7
Impacts of solar geoengineering
• potentially quick to change temperature• addresses a symptom (not the cause)
• rate of change – potentially quite fast (on and off)
• long term commitment?• ocean acidification– untreated or possible worsened
• decreased global precipitation– evident in some modelling results
• residual warming– i.e. still warmer in poles
Slide 7
Types of geoengineeringSlide 8
Carbon removal
LandOcean
LandOcean Geology
Novel
Surface
Reflective approaches
Troposphere
Stratosphere
Space
Land Ocean
Impacts of geoengineering
• Impacts– direct or indirect – intended or unintended
• Local, regional, global– displaced spatially and/or temporally
• Example: marine stratocumulus albedo change• Example: large scale afforestation
Slide 9
Impacts of geoengineering
• Impacts– direct or indirect – intended or unintended
• Local, regional, global– displaced spatially and/or temporally
• Example: marine stratocumulus albedo change• Example: large scale afforestation
Slide 9
Impacts of geoengineering
• Impacts– direct or indirect – intended or unintended
• Local, regional, global– displaced spatially and/or temporally
• Example: marine stratocumulus albedo change• Example: large scale afforestation
Slide 9
Example: Marine stratocumulus albedo changeSlide 10
LocalGlobal
Indirect
Direct
regional cooling
global cooling
surface water cooling
Example: Marine stratocumulus albedo changeSlide 10
LocalGlobal
Indirect
Direct
regional cooling
global cooling
delayed precipitation
surface water cooling
water column light attenuation
water column stratification
Example: Marine stratocumulus albedo changeSlide 10
LocalGlobal
Indirect
Direct
regional cooling
global cooling
delayed precipitation
surface water cooling
water column light attenuation
water column stratification
impact on phytoplankton?perturb ENSO?
Changes to ocean carbon sink ?
Example: Large scale afforestationSlide 11
LocalGlobal
Indirect
Directregional albedo
change
global cooling
water demand
fertiliser addition
fertiliser runoff atmospheric
chemistry - VOC production
Example: Large scale afforestationSlide 11
LocalGlobal
Indirect
Directregional albedo
change
global cooling
water demand
fertiliser addition
fertiliser runoff
impact on river systems?
regional impact on water cycle?
atmospheric chemistry - VOC
production
Impacts of geoengineering
• Traceable, attributable– spatially and/or temporally displaced
• Ability to distinguish from natural variability and/or anthropogenic climate change?– particularly for solar geoengineering
• Example: Atlantic sea surface temperatures• Example: Southern Ocean
Slide 12
Impacts of geoengineering
• Traceable, attributable– spatially and/or temporally displaced
• Ability to distinguish from natural variability and/or anthropogenic climate change?– particularly for solar geoengineering
• Example: Atlantic sea surface temperatures• Example: Southern Ocean
Slide 12
Impacts of geoengineering
• Traceable, attributable– spatially and/or temporally displaced
• Ability to distinguish from natural variability and/or anthropogenic climate change?– particularly for solar geoengineering
• Example: Atlantic sea surface temperatures• Example: Southern Ocean
Slide 12
Example: Atlantic
• Modelling solar geoengineering– (Lunt et al 2008, Latham et al 2008)– increased Atlantic North-South gradient in sea surface temperatures– cooling in South Atlantic relative to North Atlantic
• Atlantic N-S gradient – controlling factor in West African Monsoon activity– well correlated with precipitation in the Sahel (Peyrille et al 2007)– correlated with reduction in dry season rainfall in West Amazonian (Cox et
al 2008)
• Potential impacts on Amazon or West African Monsoon
• Traceable? Attributable?
Slide 13
Example: Atlantic
• Modelling solar geoengineering– (Lunt et al 2008, Latham et al 2008)– increased Atlantic North-South gradient in sea surface temperatures– cooling in South Atlantic relative to North Atlantic
• Atlantic N-S gradient – controlling factor in West African Monsoon activity– well correlated with precipitation in the Sahel (Peyrille et al 2007)– correlated with reduction in dry season rainfall in West Amazonian (Cox et
al 2008)
• Potential impacts on Amazon or West African Monsoon
• Traceable? Attributable?
Slide 13
Example: Atlantic
• Modelling solar geoengineering– (Lunt et al 2008, Latham et al 2008)– increased Atlantic North-South gradient in sea surface temperatures– cooling in South Atlantic relative to North Atlantic
• Atlantic N-S gradient – controlling factor in West African Monsoon activity– well correlated with precipitation in the Sahel (Peyrille et al 2007)– correlated with reduction in dry season rainfall in West Amazonian (Cox et
al 2008)
• Potential impacts on Amazon or West African Monsoon
• Traceable? Attributable?
Slide 13
Example: Atlantic
• Modelling solar geoengineering– (Lunt et al 2008, Latham et al 2008)– increased Atlantic North-South gradient in sea surface temperatures– cooling in South Atlantic relative to North Atlantic
• Atlantic N-S gradient – controlling factor in West African Monsoon activity– well correlated with precipitation in the Sahel (Peyrille et al 2007)– correlated with reduction in dry season rainfall in West Amazonian (Cox et
al 2008)
• Potential impacts on Amazon or West African Monsoon
• Traceable? Attributable?
Slide 13
Example: Southern Ocean
• Stratospheric ozone depletion (Tilmes et al 2008)– Stratospheric ozone depletion over Antarctica – key driver of observed changes in the Southern Hemisphere Annular Mode
(SAM) in recent decades (Thompson & Solomon, 2002)– which is also contributed to by greenhouse gas forcing (Perlwitz et al 2008)
• Southern Hemisphere Annular Mode (SAM)– Observed strengthening of Southern Ocean winds has been attributed to
the shift of the SAM to a positive state (Perlwitz et al 2008)
• Reduced efficiency of Southern Ocean carbon sink– The strengthening of these winds has been suggested to cause a reduction
in the efficiency of the Southern Ocean carbon sink (Le Quere et al 2007)
• Traceable? Attributable?
Slide 14
Example: Southern Ocean
• Stratospheric ozone depletion (Tilmes et al 2008)– Stratospheric ozone depletion over Antarctica – key driver of observed changes in the Southern Hemisphere Annular Mode
(SAM) in recent decades (Thompson & Solomon, 2002)– which is also contributed to by greenhouse gas forcing (Perlwitz et al 2008)
• Southern Hemisphere Annular Mode (SAM)– Observed strengthening of Southern Ocean winds has been attributed to
the shift of the SAM to a positive state (Perlwitz et al 2008)
• Reduced efficiency of Southern Ocean carbon sink– The strengthening of these winds has been suggested to cause a reduction
in the efficiency of the Southern Ocean carbon sink (Le Quere et al 2007)
• Traceable? Attributable?
Slide 14
Example: Southern Ocean
• Stratospheric ozone depletion (Tilmes et al 2008)– Stratospheric ozone depletion over Antarctica – key driver of observed changes in the Southern Hemisphere Annular Mode
(SAM) in recent decades (Thompson & Solomon, 2002)– which is also contributed to by greenhouse gas forcing (Perlwitz et al 2008)
• Southern Hemisphere Annular Mode (SAM)– Observed strengthening of Southern Ocean winds has been attributed to
the shift of the SAM to a positive state (Perlwitz et al 2008)
• Reduced efficiency of Southern Ocean carbon sink– The strengthening of these winds has been suggested to cause a reduction
in the efficiency of the Southern Ocean carbon sink (Le Quere et al 2007)
• Traceable? Attributable?
Slide 14
Example: Southern Ocean
• Stratospheric ozone depletion (Tilmes et al 2008)– Stratospheric ozone depletion over Antarctica – key driver of observed changes in the Southern Hemisphere Annular Mode
(SAM) in recent decades (Thompson & Solomon, 2002)– which is also contributed to by greenhouse gas forcing (Perlwitz et al 2008)
• Southern Hemisphere Annular Mode (SAM)– Observed strengthening of Southern Ocean winds has been attributed to
the shift of the SAM to a positive state (Perlwitz et al 2008)
• Reduced efficiency of Southern Ocean carbon sink– The strengthening of these winds has been suggested to cause a reduction
in the efficiency of the Southern Ocean carbon sink (Le Quere et al 2007)
• Traceable? Attributable?
Slide 14
What we do (and don’t) know...
• Generally very little about ecosystem impacts due to lack of large scale testing...
• ...just have extrapolation of natural analogues and/or modelling work
• Ecosystem impacts – general terms i.e. carbon or solar• direct and indirect, scale (local to global)
– intervention specific, i.e. impacts of biochar• direct and indirect, scale (local to global)
Slide 15
What we do (and don’t) know...
• Generally very little about ecosystem impacts due to lack of large scale testing...
• ...just have extrapolation of natural analogues and/or modelling work
• Ecosystem impacts – general terms i.e. carbon or solar• direct and indirect, scale (local to global)
– intervention specific, i.e. impacts of biochar• direct and indirect, scale (local to global)
Slide 15
What we do (and don’t) know...
• Generally very little about ecosystem impacts due to lack of large scale testing...
• ...just have extrapolation of natural analogues and/or modelling work
• Ecosystem impacts – general terms i.e. carbon or solar• direct and indirect, scale (local to global)
– intervention specific, i.e. impacts of biochar• direct and indirect, scale (local to global)
Slide 15
Conclusions
• Types of geoengineering
• Framework for impacts– scale– direct/indirect
• Limited information on potential ecosystem impacts
Slide 16
Carbon Solar
Conclusions
• Types of geoengineering
• Framework for impacts– scale– direct/indirect
• Limited information on potential ecosystem impacts
Slide 16
LocalGlobal
Indirect
Direct
Carbon Solar
Conclusions
• Types of geoengineering
• Framework for impacts– scale– direct/indirect
• Limited information on potential ecosystem impacts
Slide 16
LocalGlobal
Indirect
Direct
Carbon Solar
Thank you
Imagery: freeimages.co.uk, NASA, Carbon Engineering Ltd
ReferencesVaughan & Lenton (in press) A review of climate geoengineering proposals Climatic Change Cox et al (2008) Increasing risk of Amazonian drought due to decreasing aerosol pollution Nature 453:212Peyrille et al (2007) An idealised two-dimensional framework to study the West African Monsoon. Part I: validationand key controlling factors J Atmos Sci 64:2765Lunt et al (2008) ‘Sunshade world’: a fully coupled GCM evaluation of the climatic impacts of geoengineering Geophys Res Lett 35:L12710Latham et al (2008) Global temperature stabilization via controlled albedo enhancement of low-level maritime clouds Phil Trans R Soc A 366:3969Thompson & Solomon (2002) Interpretation of recent southern hemisphere climate change. Science 296:895Le Quere et al (2007) Saturation of the Southern Ocean CO2 sink due to recent climate change. Science 316:1735Perlwitz et al (2008) Impact of stratospheric ozone hole recovery on Antarctic climate. Geophys Res Lett 35:L08714Tilmes et al (2008) The sensitivity of Polar ozone depletion to proposed geoengineering schemes. Science 320:1201
Slide 17