Climate scenario: CCSM3_A1B

IPCC scenario: A1B

Main assumptions

  • Rapid economic growth.
  • A global population that reaches 9 billion in 2050 and then gradually declines.
  • The quick spread of new and efficient technologies.
  • A convergent world - income and way of life converge between regions. Extensive social and cultural interactions worldwide.
  • A balanced emphasis on all energy sources.

Reference

Nakićenović, N., Alcamo, J., Davis, G., de Vries, B., Fenhann, J., Gaffin, S., Gregory, K. and Grübler, A. (2000) Special Report on Emissions Scenarios, Working Group III, Intergovernmental Panel on Climate Change (IPCC). Cambridge University Press, Cambridge.

Global model: CCSM3

Reference

Collins,W.D., Bitz, C.M., Blackmon, M.L., Bonan, G.B., Bretherton,
C.S. and co-authors. (2006) The community climate system model
version 3 (CCSM3). J. Clim., 19:2122–2143.

Regional model: RCA3

Reference

Samuelsson, P., Jones, C. G., Willén, U., Ullerstig, A., Gollvik, S., Hansson, U., Jansson, C., Kjellström, E., Nikulin, G. and Wyser, K. (2011) The Rossby Centre Regional Climate model RCA3: model description and performance. Tellus A, 63:4–23.

Pan-European characteristics

This projection is included (nr. 4 in Table 1) in the investigation by Kjellström et al. (2011). There, the estimated future Pan-European changes (from 1961-1990 to 2071-2100) were compared with five other A1B-projections in terms of winter temperature (Fig. 4), summer temperature (5), winter precipitation (8) and summer precipitation (9).

Winter temperature

In most parts of Europe, the future increase in projection CCSM3_A1B is smaller than the average change of all six A1B-projections considered.

Summer temperature

In most parts of Europe, the future increase in projection CCSM3_A1B is smaller than the average change of all six A1B-projections considered.

Winter precipitation

In Norway, U.K. and north-central Europe, a small decrease is indicated in projection CCSM3_A1B, in contrast to the general increase indicated in the average change of all six A1B-projections considered. In the rest of Europe, the future change in projection CCSM3_A1B is close to the average changes of all six A1B-projections considered.

Summer precipitation

In Scandinavia, a small decrease is indicated in projection CCSM3_A1B, in contrast to the general increase indicated in the average change of all six A1B-projections considered. In southernmost Europe, the future decrease in projection CCSM3_A1B is larger than the average change of all six A1B-projections considered. In the rest of Europe, the future change in projection CCSM3_A1B is close to the average changes of all six A1B-projections considered.

Further, average temperature and annual precipitation changes in Scandinavia (from 1961-1990 to 2011-2040, 2041-2070 and 2071-2100) in all 16 projections were compared by Kjellström et al. (2011) (Fig. 10). Generally, the future increases in temperature and precipitation are linearly related, where a weak temperature increase corresponds to a weak precipitation increase, and vice versa. Below, “increase” corresponds to both temperature and precipitation; “small” means that the increase is among the smaller ones of all 16 projections considered, “medium” that the increase is among the middle ones, and “large” that the increase is among the larger ones, for the period considered.

As compared with all 16 projections considered, the increase in projection CCSM3_A1B is:
2011-2040: medium
2041-2070: medium
2071-2100: small

Reference

Kjellström, E., Nikulin, G., Hansson, U., Strandberg, G. and Ullerstig, A. (2011) 21st century changes in the European climate: uncertainties derived from an ensemble of regional climate model simulations. Tellus A, 63:24–40.