Enviropedia
Climate Change
Global Warming
Ozone
Air Pollution
Weather & Climate
Sustainability
Kids
INFORMATION
Climate System
Climate Change
Empirical Study
Climate Models
Palaeoclimates
Global Warming
Introduction
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 Trace Gases
 - Adjustment Time
 - Summary
Greenhouse Forcing
 - Forcing Factors
 - GWPs
 - ΔF-ΔC Relationships
 - 1765 to 1990
 - Ozone
Aerosols
 - Aerosols
 - Radiative Forcing
   - Direct
   - Indirect
 - Total Forcing
Climate Variations
 - Surface Temperature
 - Precipitation
 - Other Variations
   - Stratosphere
   - Cryosphere
   - Circulation
   - Cloudiness
Detection
 - Modelling
 - Attribution
   - Latitudes
   - Stratosphere
   - Precipitation
   - Sea Level Rise
   - Fingerprints
 - When?
Future Climate
 - GCM Simulations
 - Feedbacks
   - Water Vapour
   - Clouds
   - Ice Albedo
   - Greenhouse Gases
 - 21st Century
Impacts
 - Agriculture
 - Forestry
 - Ecosystems
 - Water Resources
 - Oceans & Coasts
 - Humans & Health
Responses
 - Stabilising
 - FCCC
 - Kyoto Protocol
 - UK Programme
   - Energy Demand
   - Energy Supply
 - Evaluation
Conclusion
LINKS
Navigate

6.9.2. Greenhouse Feedbacks

GCMs have estimated the CO2 doubling temperature change in the absence of feedback processes to be approximately 1.2C. The existence of feedback loops within the climate system results in a climate sensitivity of 1.5C to 4.5C, and makes an otherwise linear association between radiative forcing and global temperature distinctly non-linear. Three of the most important direct climatic feedbacks to greenhouse forcing include the water vapour feedback, the cloud feedback and the ice-albedo feedback. (See also section 2.7).