IPCC Fourth Assessment Report: Climate Change 2007
Climate Change 2007: Working Group I: The Physical Science Basis

Chapter 10: Global Climate Projections

Executive Summary

Mean Temperature

Temperature Extremes

Mean Precipitation

Precipitation Extremes and Droughts

Snow and Ice

Carbon Cycle

Ocean Acidification

Sea Level

Mean Tropical Pacific Climate Change

El Niño


Sea Level Pressure

Tropical Cyclones (Hurricanes and Typhoons)

Mid-latitude Storms

Atlantic Ocean Meridional Overturning Circulation

Radiative Forcing

Climate Change Commitment (Temperature and Sea Level)

10.1 Introduction

10.2 Projected Changes in Emissions, Concentrations and Radiative Forcing

10.2.1 Emissions Scenarios and Radiative Forcing in the Multi-Model Climate Projections

10.2.2 Recent Developments in Projections of Radiative Species and Forcing for the 21st Century

10.3 Projected Changes in the Physical Climate System

10.3.1 Time-Evolving Global Change

10.3.2 Patterns of Change in the 21st Century

10.3.3 Changes in Ocean/Ice and High-Latitude Climate

10.3.4 Changes in the Atlantic Meridional Overturning Circulation

10.3.5 Changes in Properties of Modes of Variability

FAQ 10.1 Are Extreme Events, Like Heat Waves, Droughts or Floods, Expected to Change as the Earth’s Climate Changes? 

10.3.6 Future Changes in Weather and Climate Extremes

10.4 Changes Associated with Biogeochemical Feedbacks and Ocean Acidification

10.4.1 Carbon Cycle/Vegetation Feedbacks

10.4.2 Ocean Acidification Due to Increasing Atmospheric Carbon Dioxide

10.4.3 Simulations of Future Evolution of Methane, Ozone and Oxidants

10.4.4 Simulations of Future Evolution of Major Aerosol Species

10.5 Quantifying the Range of Climate Change Projections

10.5.1 Sources of Uncertainty and Hierarchy of Models

10.5.2 Range of Responses from Different Models

10.5.3 Global Mean Responses from Different Scenarios

10.5.4 Sampling Uncertainty and Estimating Probabilities

10.6 Sea Level Change in the 21st Century

10.6.1 Global Average Sea Level Rise Due to Thermal Expansion

10.6.2 Local Sea Level Change Due to Change in Ocean Density and Dynamics

10.6.3 Glaciers and Ice Caps

10.6.4 Ice Sheets

FAQ 10.2 How Likely are Major or Abrupt Climate Changes, such as Loss of Ice Sheets or Changes in Global Ocean Circulation? 

10.6.5 Projections of Global Average Sea Level Change for the 21st Century

10.7 Long Term Climate Change and Commitment

10.7.1 Climate Change Commitment to Year 2300 Based on AOGCMs

FAQ 10.3 If Emissions of Greenhouse Gases are Reduced, How Quickly do Their Concentrations in the Atmosphere Decrease? 

10.7.2 Climate Change Commitment to Year 3000 and Beyond to Equilibrium

10.7.3 Long-Term Integrations: Idealised Overshoot Experiments

10.7.4 Commitment to Sea Level Rise


Appendix 10.A: Methods for Sea Level Projections for the 21st Century

10.A.1 Scaling MAGICC Results

10.A.2 Mass Balance Sensitivity of Glaciers and Ice Caps

10.A.3 Area Scaling of Glaciers and Ice Caps

10.A.4 Changes in Ice Sheet Surface Mass Balance

10.A.5 Changes in Ice Sheet Dynamics

10.A.6 Combination of Uncertainties

10.A.7 Change in Surface Air Temperature Over the Major West Antarctic Ice Shelves

Coordinating Lead Authors:

Gerald A. Meehl (USA), Thomas F. Stocker (Switzerland)

Lead Authors:

William D. Collins (USA), Pierre Friedlingstein (France, Belgium), Amadou T. Gaye (Senegal), Jonathan M. Gregory (UK), Akio Kitoh (Japan), Reto Knutti (Switzerland), James M. Murphy (UK), Akira Noda (Japan), Sarah C.B. Raper (UK), Ian G. Watterson (Australia), Andrew J. Weaver (Canada), Zong-Ci Zhao (China)

Contributing Authors:

R.B. Alley (USA), J. Annan (Japan, UK), J. Arblaster (USA, Australia), C. Bitz (USA), P. Brockmann (France), V. Brovkin (Germany, Russian Federation), L. Buja (USA), P. Cadule (France), G. Clarke (Canada), M. Collier (Australia), M. Collins (UK), E. Driesschaert (Belgium), N.A. Diansky (Russian Federation), M. Dix (Australia), K. Dixon (USA), J.-L. Dufresne (France), M. Dyurgerov (Sweden, USA), M. Eby (Canada), N.R. Edwards (UK), S. Emori (Japan), P. Forster (UK), R. Furrer (USA, Switzerland), P. Gleckler (USA), J. Hansen (USA), G. Harris (UK, New Zealand), G.C. Hegerl (USA, Germany), M. Holland (USA), A. Hu (USA, China), P. Huybrechts (Belgium), C. Jones (UK), F. Joos (Switzerland), J.H. Jungclaus (Germany), J. Kettleborough (UK), M. Kimoto (Japan), T. Knutson (USA), M. Krynytzky (USA), D. Lawrence (USA), A. Le Brocq (UK), M.-F. Loutre (Belgium), J. Lowe (UK), H.D. Matthews (Canada), M. Meinshausen (Germany), S.A. Müller (Switzerland), S. Nawrath (Germany), J. Oerlemans (Netherlands), M. Oppenheimer (USA), J. Orr (Monaco, USA), J. Overpeck (USA), T. Palmer (ECMWF, UK), A. Payne (UK), G.-K. Plattner (Switzerland), J. Räisänen (Finland), A. Rinke (Germany), E. Roeckner (Germany), G.L. Russell (USA), D. Salas y Melia (France), B. Santer (USA), G. Schmidt (USA, UK), A. Schmittner (USA, Germany), B. Schneider (Germany), A. Shepherd (UK), A. Sokolov (USA, Russian Federation), D. Stainforth (UK), P.A. Stott (UK), R.J. Stouffer (USA), K.E. Taylor (USA), C. Tebaldi (USA), H. Teng (USA, China), L. Terray (France), R. van de Wal (Netherlands), D. Vaughan (UK), E. M. Volodin (Russian Federation), B. Wang (China), T. M. L. Wigley (USA), M. Wild (Switzerland), J. Yoshimura (Japan), R. Yu (China), S. Yukimoto (Japan)

Review Editors:

Myles Allen (UK), Govind Ballabh Pant (India)

This chapter should be cited as:

Meehl, G.A., T.F. Stocker, W.D. Collins, P. Friedlingstein, A.T. Gaye, J.M. Gregory, A. Kitoh, R. Knutti, J.M. Murphy, A. Noda, S.C.B. Raper, I.G. Watterson, A.J. Weaver and Z.-C. Zhao, 2007: Global Climate Projections. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.