Hi, I'm Xavier Auclert

    Wikipedia

    What?

    Summary

    Notes

    Intro

    • Commonly: Geoengineering, but confusion on terms
    • = Deliberate and large scale intervention on climate
    • Most agree that it is not a solution, but can be part of a array of solutions
    • Risks must be evaluated vs. risks of dangerous climate change

    Solar geoengineering / Albedo altering

    Solar geoengineering - Wikipedia

    Solar geoengineering, or solar radiation modification (SRM) is a proposed type of climate engineering in which sunlight (solar radiation) would be reflected back to space to limit or reverse human-caused climate change. Most methods would increase the planetary albedo (reflectivity), for example with stratospheric aerosol injection.

    en.wikipedia.org

    Solar geoengineering - Wikipedia
    • Do not reduce CO2 concentration = not a substitute to change mitigation, ex. no impact on climate accidification
    • Cheap: tens of billions of USD
    • Seems reversible
    • Could be used to avoid tipping points for example
    • Different types
      • Stratospheric aerosol injection
      • Marine cloud brightening
      • cirrus cloud thinning
    • Some are based on natural phenomena
    • Key governance issue:
      • Who decides? How?
      • How much?
      • What type?
    🤔
    Main issue is risk and unknowns

    Carbon dioxide removal

    Carbon dioxide removal - Wikipedia

    Carbon dioxide removal (CDR), also known as greenhouse gas removal, is a process in which carbon dioxide gas () is removed from the atmosphere and sequestered for long periods of time - in the context of net zero greenhouse gas emissions targets, CDR is increasingly integrated into climate policy.

    en.wikipedia.org

    Carbon dioxide removal - Wikipedia
    • Carbon removal / sequestration
      • Sucking it out of the athmosphere
        • Direct air capture
        • Carbon Capture and Storage with Bioenergy
          • Leakage?
      • promoting natural processes that do so
        • Reforestation / Afforestation
    • Slow, expensive
      • Their impact is proportional to their scale
      • Can they be scaled?
    • Some don't see it as cliamteengineering because it's small scale
    • Key governance issue
      • Like reductions: making sure everyone caries their load
    🤔
    What touches the causes? what touches the symptomes? Main issue is scale and speed

    Issues

    • Because it is intentional: different morally than unintentional climate change: do we have the right to do so?
    • Religion play a role in the debate
      • Some say we cannot play the role of god
      • others that we are stewards of his creation
    • How do we choose the target temperature? target climate?
      • Different regions, different expectations
      • Politically: how do we get to an agreement when we can't even decide on reductions? Currrent negotiation frameworks do not work.
    🤔
    What if a region wants to IMPROVE their climate? (less cold)
    • Climate justice issue
      • Who will suffer? most likely not the ones that are benefiting from the emissions (north / top100 companies)
      • On the other side: the rich will pay for climate engineering, it helps mitigate inequalities
    • Positions
      • Some do not know where they position themeselves
      • Some are opposed
      • Some are ok with nature-based CO2 removal: afforestation...
      • Think tanks opposing emission reductions are generally supportive
    • Risk compensation: risk that emissions will not lower because we think there is a solution = reluctance to even discuss it
      • Other research shows that the threat of geoengineering might actually increase emission reduction
    🤔
    Why are we not even discussing it? Need to explain this point

    Governance

    • There is no global governance
    • Part of the Convention on Biological Diversity
      • 2010 - "climate-related geo-engineering activities that may affect biodiversity" until these are governed, they are scientifically justified, and associated risks have been considered.
    • Oxford Principles used by the UK / created by Oxford U
      • Principle 1: Geoengineering to be regulated as a public good.
      • Principle 2: Public participation in geoengineering decision-making
      • Principle 3: Disclosure of geoengineering research and open publication of results
      • Principle 4: Independent assessment of impacts
      • Principle 5: Governance before deployment

    Public perception

    • Low! <20% reported prior knowledge
    • Seen as risky. Removal preferred over solar engineering
    • Seen as last resort
    • Unorthodox claims: secret government actions are already creating winter / fires etc.

    Evaluations

    • What we know today is mostly based on:
      • Lab experiments
      • Observations of natural phenomena
      • Models
    • Some technics are based on natural phenomena (ex. Pinatubo)
    • It's very early stage ... we don't know much.
    • The Royal society concludes that the focus should be on reductions + investigate in case it becomes necessary (tipping point)