Introduction

Climate System

Causes of Climate Change

Empirical Study of Climate

Climate Modelling

Palaeoclimatic Change

Contemporary Climate Change

Epilogue
Appendix
References

6.11.1. Stabilising Greenhouse Gas Concentrations

Table 6.9 illustrates the reductions in emissions of the most important greenhouse gases that would be required now to stabilise atmospheric concentrations at present day levels (IPCC, 1990a).

Table 6.9. Reductions in greenhouse gas emissions required to stabilise atmospheric concentrations

The Montreal Protocol and subsequent amendments have already significantly reduced many of the halocarbon species, particularly the CFCs, by at least 90% in developed nations, to halt the destruction of stratospheric ozone. Paradoxically, as the ozone layer slowly repairs itself, its greenhouse forcing will increase.

Far more importantly, however, are the other greenhouse gases, most noticeably carbon dioxide, the major greenhouse gas that is increasing anthropogenically, and the by-product of the world's energy production. Clearly, a 60% cut in carbon dioxide emissions, either now or over the next few years, would be almost impossible to achieve. Even the most optimistic IPCC emissions scenario (IS92c) projects a rise in carbon emissions by 2025, with only a gradual decline by the year 2100. In view of this, it is worth examining what action is being taken by the global community to safeguard against the impacts of anthropogenic climate change.

Greenhouse Effect

Enhanced G-Effect

Greenhouse Gases
 -Carbon Dioxide
  ·Sources
  ·Sinks
  ·Carbon Cycle
  ·Concentrations
  ·Equilibrium
 -Methane
  ·Sources
  ·Sinks
  ·Concentrations
 -Nitrous Oxide
  ·Sources
  ·Sinks
  ·Concentrations
 -Halocarbons
  ·Sources
  ·Sinks
  ·Concentrations
 -Ozone
 -Other Gases
 -Lifetimes
 -Summary

Greenhouse Forcing
 -Forcing Factors
 -GWPs
 -ΔF-ΔC
 -1765 to 1990
 -Ozone

Aerosols
 -Sources & Sinks
 -Forcing
  ·Direct
  ·Indirect
 -Total Forcing

Climate Variations
 -Surface Temp.
 -Precipitation
 -Other
  ·Stratosphere
  ·Cryosphere
  ·Atmos. Circulation
  ·Cloudiness

Detection
 -Modelling
 -Attribution
  ·Latitudes.
  ·Stratosphere
  ·Precipitation
  ·Sea Level
  ·Fingerprints
 -When?

Future Climate
 -GCM Simulations
 -Feedbacks
  ·Water Vapour
  ·Clouds
  ·Ice Albedo
  ·G-house Gases
 -21st Century

Impacts
 -Agriculture
 -Forestry
 -Ecosystems
 -Water Resources
 -Oceans/Coasts
 -Human & Health

Responses
 -Stabilising
 -FCCC
 -Kyoto Protocol
 -UK Programme
  ·Energy Demand
  ·Energy Supply
 -Evaluation