Climate scenarios: ECHAM5_A1B_3

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: ECHAM5

Initialisation: Member 3

Reference

Roeckner, E., Bäuml, G., Bonaventura, L., Brokopf, R., Esch, M., Giorgetta, M., Hagemann, S., Kirchner, I., Kornblueh, L., Manzini, E., Rhodin, A., Schlese, U., Schulzweida, U. and Tompkins, A. (2003) The atmospheric general circulation model ECHAM5. PART I: Model description. Technical Report, Max Planck Institute for Meteorology, MPI-Report 349.

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. 11 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 all parts of Europe, the future change in projection ECHAM5_A1B_3 is close to the average change of all six A1B-projections considered.

Summer temperature

In all parts of Europe, the future change in projection ECHAM5_A1B_3 is close to the average change of all six A1B-projections considered.

Winter precipitation

In western central Europe, the future increase in projection ECHAM5_A1B_3 is larger than the average change of all six A1B-projections considered. In Norway, a small decrease is indicated in projection ECHAM5_A1B_3, 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 ECHAM5_A1B_3 is close to the average changes of all six A1B-projections considered.

Summer precipitation

In parts of southern Europe, the future decrease in projection ECHAM5_A1B_3 is larger than the average change of all six A1B-projections considered. In the rest of Europe, the future change in projection ECHAM5_A1B_3 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 ECHAM5_A1B_3 is:
2011-2040: small
2041-2070: small/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.