Languages:
 

Simulated annual global mean surface temperatures

Figure 4: Simulating the Earth's temperature variations, and comparing the results to measured changes, can provide insight into the underlying causes of the major changes.

A climate model can be used to simulate the temperature changes that occur both from natural and anthropogenic causes. The simulations represented by the band in (a) were done with only natural forcings: solar variation and volcanic activity. Those encompassed by the band in (b) were done with anthropogenic forcings: greenhouse gases and an estimate of sulphate aerosols, and those encompassed by the band in (c) were done with both natural and anthropogenic forcings included. From (b), it can be seen that inclusion of anthropogenic forcings provides a plausible explanation for a substantial part of the observed temperature changes over the past century, but the best match with observations is obtained in (c) when both natural and anthropogenic factors are included. These results show that the forcings included are sufficient to explain the observed changes, but do not exclude the possibility that other forcings may also have contributed. The bands of model results presented here are for four runs from the same model. Similar results to those in (b) are obtained with other models with anthropogenic forcing."
[Based upon Chapter 12 , Figure 12.7 ]

Source & © IPCC TAR SPM of WG1 

Related publication:
Climate Change (2001) homeClimate Change 2001 Assessment
Other Figures & Tables on this publication:

Adaptive Capacity, Vulnerability, and Key Concerns by Region

Facts on environmental matters

Table SPM.1 Estimates of potential global greenhouse gas emission reductions in 2010 and in 2020

The Emissions Scenarios from the Special Report on Emissions Scenarios (SRES)

Expert Links on Climate Change

Expert Links on Climate Change

Links on Climate Change

Expert Links on Climate Change

Expert Links on Climate Change

Expert Links on Climate Change

Expert Links on Climate Change

Expert Links on Climate Change

Other views on Climate Change

Footnotes for the Summary for Policymakers of IPCC Working Group III

Footnotes for Table 1 of IPCC SPM WG II

Footnotes for the Summary for Policymakers of IPCC Working Group 1

Footnotes for the Summary for Policymakers of IPCC Working Group II

Variations of the Earth's surface temperature for :

Indicators of the human influence on the atmosphere during the Industrial Era

The global mean radiative forcing of the climate system for the year 2000, relative to 1750

Simulated annual global mean surface temperatures

The global climate of the 21st Century

Documented Climate Change Impacts

Figure SPM-2 - Reasons for Concern

Figure SPM-3 - Projected Changes in Annual Runoff

Carbon in Oil, Gas and Coal Reserves Compared with Historic Fossil Fuel Carbon Emissions (in gigatonnes)

Footnotes to Table SPM-1 (Question 6.2.2)

Figure 8.1 Precipitation

Figure 8.2 Hurricanes

Schematic of observed variations of the temperature indicators / the hydrological and storm-related indicators

Many external factors force climate change

The annual mean change of the temperature (colour shading) and its range (isolines)

Analysis of inter-model consistency in regional relative warming

GCRIO

UNFCCC

Pew Climate

NCDC

Climate Ark

Climatic Research Unit

CICERO

World Business Council for Sustainable Development

Expert Links on Climate Change