A framework for possible geoengineering impacts Dr Nem Vaughan Tyndall Centre for Climate Change Research University of East Anglia 31 st January

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 geoengineering Slide 3 Vaughan & Lenton (in press) Climatic Change

Carbon geoengineering Slide 4 Capture Storage Carbon removal LandOcean LandOceanGeology Novel

Carbon geoengineering Slide 4 Capture Storage Carbon removal LandOcean LandOceanGeology Novel

Carbon geoengineering Slide 4 Capture Storage Carbon removal LandOcean LandOceanGeology Novel

Solar geoengineering Slide 5 Surface Reflective approaches Troposphere Stratosphere Space Land Ocean

Solar geoengineering Slide 5 Surface Reflective approaches Troposphere Stratosphere Space Land Ocean

Impacts of carbon geoengineering Addresses excess of CO 2 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 CO 2 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 CO 2 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 CO 2 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 CO 2 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 geoengineering Slide 8 Capture Storage Carbon removal LandOcean LandOceanGeology 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 change Slide 10 LocalGlobal Indirect Direct regional cooling global cooling surface water cooling

Example: Marine stratocumulus albedo change Slide 10 LocalGlobal Indirect Direct regional cooling global cooling delayed precipitation surface water cooling water column light attenuation water column stratification

Example: Marine stratocumulus albedo change Slide 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 afforestation Slide 11 LocalGlobal Indirect Direct regional albedo change global cooling water demand fertiliser addition fertiliser runoff atmospheric chemistry - VOC production

Example: Large scale afforestation Slide 11 LocalGlobal Indirect Direct regional 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 References Vaughan & 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 453:212 Peyrille et al (2007) An idealised two-dimensional framework to study the West African Monsoon. Part I: validation and key controlling factors J Atmos Sci 64:2765 Lunt et al (2008) ‘Sunshade world’: a fully coupled GCM evaluation of the climatic impacts of geoengineering Geophys Res Lett 35:L12710 Latham et al (2008) Global temperature stabilization via controlled albedo enhancement of low-level maritime clouds Phil Trans R Soc A 366:3969 Thompson & Solomon (2002) Interpretation of recent southern hemisphere climate change. Science 296:895 Le Quere et al (2007) Saturation of the Southern Ocean CO2 sink due to recent climate change. Science 316:1735 Perlwitz et al (2008) Impact of stratospheric ozone hole recovery on Antarctic climate. Geophys Res Lett 35:L08714 Tilmes et al (2008) The sensitivity of Polar ozone depletion to proposed geoengineering schemes. Science 320:1201 Slide 17