Countermeasures to climate change

Classification (which Masuda thinks reasonable)

• Adaptation
• Mitigation (mainly reduction of emission)
• Carbon capture and sequestration (CCS, considered as part of mitigation) + carbon dioxide removal from the atmosphere (CDR, considered as part of "geoengineering")
• Intervention to climate (mainly solar radiation modification, SRM) (part of "geoengineering")

Weight in discourses (subjective evaluation by Masuda)

Adaptation

• People has adapted to climate and to (natural) climate change.
• Adaptation to changing climate will become necessary. In adaptation to climate itself, there is no need to separate natural and anthropogenic parts.
• When it is required to determine who should pay the cost, responsibility of the "emitters" will be an issue. (Share in emission is a matter of fact, and responsibility is a matter of norm. They are different things. But they are considered to be related.)
• Traditionally, people often adapted by long-range migration.
• At present, long-range migration is difficult by social reasons (national boundaries and land ownership). It is considered that each nation should conduct adaptation policy, with international collaboration as auxiliary help.
• In such cases where significant loss of habitable land is anticipated (such as small flat island countries), international migration must be considered.
• Adaptation in agriculture ... (discussed in connection to impacts in agriculture)
• Adaptation in flood management (e.g. in Japan)
  • Planning of construction (dams, levees, etc.) has been based on the idea that statistical distribution of river flow remains constant. In changing climate, its statistical distribution will also change.
  • Probability of severe floods is likely to increase, and construction to hold them may be too costly.
  • Such "soft" ways as predition and evacuation seem more important.
  • Stronger regulation of land use may also be necessary.

Mitigation

• Emission of carbon dioxide is deeply rooted in energy use in industrial civilization. It is difficult to reduce it.
  • cf. Preservation of stratospheric ozone ... chlorofluorocarbons ... producers are few, technology of replacement is possible.
  • cf. Long-range transboundary air polution
• "I = P A T" thinking
  • impact of human activity = population × "affluence" × "technology factor"
  • More specialized form: "Kaya (Yoichi, 1997)'s identity":
    • CO₂ emission = population × GDP/population × (energy consumption)/GDP × (CO₂ emission)/(energy consumption)
• Ways of reducing emission
  • Reducing energy demands
  • Improving efficiency of energy use (achieve the same effect with less energy consumption)
  • Changing fossil fuel to other energy resourses
    • Renewable energy
      • Solar
      • Wind
      • Hydro
      • Biomass
    • Nuclear (Note: problem of radioactive wastes, risk of accidents)
  • Choose relatively better fossil fuel (natural gas rather than coal)
• Policies to make social changes
  • Ban and punishment
  • Subsidies
  • Taxes
  • "Cap and trade"
  • Anyway, "carbon pricing" is needed, as long as we live with market economy.
• Enhancement of CO₂ sinks
  • Helping growth of forests (afforestation, reforestation)
  • Increase soil carbon storage
  • Articifical carbon capture and sequestration ... costly, but necessary??