1. Manifestations of climate change

Climate change manifests itself primarily through a gradual increase in the average temperatures of the earth’s surface, alterations in precipitation patterns, changes in the intensity and/or frequency of extreme climatic events, a slow but significant reduction in the cryosphere (including glaciers) and a rise in sea levels (IPCC, 2007a).

Greenhouse gas emissions scenarios1

Global greenhouse gas emissions Millions of metric tons of CO2 equivalent per year

40 000 60 000 80 000 100 000 120 000 140 000

20 000 0

A1F1 A1

A1T A1B

A2 B1 Post-SRES2 (max.)

A2 B2

A1F1 A1T

A1B B1

Post-SRES range (80%)

Constant year 2000

Post-SRES2 (min.) 2000 2100

Fossil intensive Non-fossil energy sources Balance across all energy sources.

Economic growth and technological change are more fragmented and slower than in other storylines.Continuously increasing global population.

Rapid changes in economic structures toward a service and information economy, with reductions in material intensity, and the introduction of clean and resource-efficient technologies. The emphasis is on global solutions to economic, social, and environmental sustainability, including improved equity, but without additional climate initiatives.

B2

Emphasis is on local solutions to economic, social, and environmental sustainability. Note: 1. In the absence of additional climate policies, from 2000 to 2100; 2. IPCC Special Report on Emission Scenarios.

Source: Intergovernmental Panel on Climate Change (IPCC), Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the IPCC, Cambridge University Press, 2007.

Figure 1.1 6

concentrations XX Century

Available scientific evidence associates the phenomenon of climate change with increased concentrations of anthropogenic greenhouse gases (GHG) in the atmosphere resulting principally from greater use of fossil fuels, changes in land use, agricultural activities, and solid waste disposal methods.

and surface temperature projections

Global surface warming Degrees centigrade

1 2 3 4 5

0 -1 1900 2000 2100 Very rapid economic growth and global population, and introduction of new and more efficient technologies: