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:
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)
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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
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