- 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.
- 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?
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.
- Carbon removal / sequestration
- Sucking it out of the athmosphere
- Direct air capture
- Carbon Capture and Storage with Bioenergy
- 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
- 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.
- 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
- 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
- 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
- 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.
- What we know today is mostly based on:
- Lab experiments
- Observations of natural phenomena
- 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)