Folland, C. K., Karl, T. R., Christy, J. R., Clarke, R. A., Gruza, G. V., Jouzel, J., Mann, M. E., Oerle-manns, J., Salinger, M. J., and Wang, S-W.: 2001, 'Observed Climate Variability and Change', in Houghton, J. H., Ding, Y., Griggs, D. J., Noguer, M., van der Linder, P. J., Dai, X., Maskell, K., and Johnson, C. A.(eds.), Climate Change 2001: The Scientific Basis, Contribution of Working Group 1 to the Third Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, UK, pp. 99-182.

Frich, P., Alexander, L. V., Della-Marta, P., Gleason, B., Haylock, M., Klein-Tank, A., Peterson, T., and Plummer, N.: 2000, Global Changes in Climatic Extremes During the Second Half of the 20th Century, Report of WMO CCL/CLIVER Working Group on Climate Change.

Hulme, M., Osborn, T. J., and Johns, T. C.: 1998, 'Precipitation sensitivity to global warming: Comparison of observations with HadCM2 simulations', Geophys. Res. Lett. 25, 3379-3382.

Hurrell, J. W.: 1995, 'Decadal trends in the North Atlantic oscillation regional temperatures and precipitation', Science 269, 676-679.

Intergovernmental Panel of Climate Change (IPCC): 1996, Climate Change 1995: The Science of Climate Change, in Houghton, J. T., Meira Filho, L. G., Callander, B. A., Harris, N., Kattenberg, A., and Maskell, K., (eds.), Cambridge University Press, Cambridge, UK., 570 pp.

Intergovernmental Panel of Climate Change (IPCC): 2000, Emissions Scenariois: Special Report on Emissions Scenarios, in Nakicenovic, N. and Swart, R. (eds.), Cambridge University Press, Cambridge, UK., 599 pp.

Intergovernmental Panel of Climate Change (IPCC): 2001a, Climate Change 2001: The Scientific Basis, in Houghton, J. H., Ding, Y., Griggs, D. J., Noguer, M., van der Linder, P. J., Dai. X., Maskell, K., and Johnson, C. A. (eds.), Cambridge University Press, Cambridge, UK., 881 pp.

Intergovernmental Panel of Climate Change (IPCC): 2001b, Climate Change 2001: Impacts, Adaptation, and Vulnerability, in McCarthy, J. J., Canziani, O. F., Leary, N. A., Dokken, D. J., and White, K. S. (eds.), Cambridge University Press, Cambridge, UK., 1032 pp.

Intergovernmental Panel of Climate Change (IPCC): 2001c, Climate Change 2001: Synthesis Report, in Watson, R. T. (ed.), Cambridge University Press, Cambridge, UK., 147 pp. and appendices.

Jones, P. D., Osborn, T. J., Briffa, K. R., Folland, C. K., Horton, E. B., Alexander, L. V., Parker, D. E., and Rayner, N. A.: 2001, 'Adjusting for sampling density in grid box land and ocean surface temperature time series', J. Geophys. Res. 106, 3371-3380(R).

Lamb, H. H.: 1982, ClimateHistory and the Modern World, Methuen and Co., London, UK., 387 pp.

Livezey, R. E. and Smith, T. M.: 1999, 'Covariability of aspects of North American climate with global sea surface temperatures on interannual to interdecadal timescales', J. Clim. 12, 289-302.

Mann, M. E., Bradley, R. S., and Hughes, M. K.: 2000, 'Long-term variability in the El Nino Southern Oscillation and associated teleconnections', in Diaz, H. F. and Markgraf, V. (eds.), El Nino and the Southern Oscillation: Multiscale Variability and its Impacts on Natural Ecosystems and Society, Cambridge University Press, Cambridge, UK., pp. 357-412.

Nicholson, S. E.: 1989, 'Long-term changes in African rainfall', Weather 44, 46-56.

Pfister,C., Brazdil, R., and Glaser, R.: 1999, Climatic Variability in Sixteenth-Century Europe and its Social Dimension, Kluwer Academic Publishers, Dordrecht, The Netherlands, 351 pp.

Power, S., Casey, T., Folland, C. K., Colman, A., and Mehta, V.: 1999, 'Inter-decadal modulation of the impact of ENSO on Australia', Clim. Dyn. 15, 319-324.

Salinger, M. J.: 1994, Climate variability, agriculture and forests, WMO Technical Note 196, Geneva.

Salinger, M. J., Allan, R., Bindoff., N., Hannah, J., Lavery, B., Lin, Z., Lindesay, J., Nicholls, N., Plummer, N., and Torok, S.:1996, 'Observed variability and change in climate and sea-level in

Oceania', in Bouma, W. J., Pearman, G. I., and Manning, M. (eds.), Greenhouse: Coping with Climate Change, CSIRO, Melbourne, pp. 100-126.

Salinger, M. J., Desjardins, R., Jones, M. B., Sivakumar, M. V. K., Strommen, N. D., Veerasamy, S., and Lianhai, W.: 1997, Climate variability, agriculture and forestry: An update, WMO Technical Note 199, Geneva.

Salinger, M. J., Desjardins, R. L., Janzen, H., Karing, P. H., Veeresamy, S., and Zipoli, G.: 1999, Climate Variability, Agriculture and Forestry: Towards Sustainability, Report of the CagM-XI Rapporteurs on the effects of climate variability and climate change on agriculture and forestry, WMO, Geneva.

Salinger, M. J., Stigter, C. J., and Das, H. P.: 2000, 'Agrometeorological adaptation strategies to increasing climate variability and change', Agric. Forest. Meteorol. 103, 167-194.

Salinger, M. J., Renwick, J. A., and Mullan, A. B.: 2001, 'Interdecadal pacific oscillation and south pacific climate', Int. J. Climatol. 21, 1705-1721.

Stahle, D. W. et al.: 1998, 'Experimental dendroclimatic reconstruction of the southern oscillation', Bull. Am. Meteorol. Soc. 79 (10), 2137-2152.

Stott, P. A., Tett, S. F. B., Jones, G. S., Allen, M. R., Mitchell, J. F. B., and Jenkins, G. J.: 2000, 'External control of twentieth century temperature variations by natural and anthropogenic forcings', Science 15, 2133-2137.

Tett, S. F. B. et al.:2000, 'Estimation of natural and anthropogenic contributions to 20th century climate', Hadley Centre Technical Note 19 , Hadley Centre for Climate Prediction and Research, Meteorological Office, UK, 52 pp.

Thompson, D. W. J. and Wallace, J. M.: 2000, 'Annual modes in the extratropical circulation Part I: Month-to-month variability', J. Clim. 13, 1000-1016.

Thompson, D. W. J., Wallace, J. M., and Hegerl, G. C.: 2000, 'Annual modes in the extratropical circulation Part II: Trends', J. Clim. 13, 1018-1036.

Trenberth, K. E. and Hoar, T. J.: 1996, 'The 1990-1995 El Nino-Southern oscillation event: Longest on record', Geophys. Res. Lett. 23, 57-60.

Wigley, T. M. L. and Raper, S. C. B.: 2001, 'Interpretation of high projections for global-mean warming', Science 293(5529), 451-454.

United Nations: 1992, United Nations Framework Convention on Climate Change. Rio de Janeiro, 33 pp.

(Received 15 December 2004; in revised form 5 May 2003)



1 World Meteorological Organization, 7bis Avenue de la Paix, 1211 Geneva 2, Switzerland E-mail: [email protected] 2India Meteorological Department, Shivaji Nagar, Pune 411005, India 3 Center for Ecology and Biophysics, 13.020-430-Campinas, Sao Paulo, Brazil

Abstract. The arid and semi-arid regions account for approximately 30% of the world total area and are inhabited by approximately 20% of the total world population. Issues of present and future climate variability and change on agriculture and forestry in the arid and semi-arid tropics of the world were examined and discussion under each of these issues had been presented separately for Asia, Africa and Latin America.

Several countries in tropical Asia have reported increasing surface temperature trends in recent decades. Although, there is no definite trend discernible in the long-term mean for precipitation for the tropical Asian region, many countries have shown a decreasing trend in rainfall in the past three decades. African rainfall has changed substantially over the last 60 yr and a number of theoretical, modelling and empirical analyses have suggested that noticeable changes in the frequency and intensity of extreme events, including floods may occur when there are only small changes in climate. Climate in Latin America is affected by the El Nino-southern oscillation (ENSO) phases and there is a close relationship between the increase and decrease of rainfall depending upon the warm or cold phases of the phenomenon.

Over land regions of Asia, the projected area-averaged annual mean warming is likely to be 1.6 ± 0.2 °C in the 2020s, 3.1 ± 0.3 °C in the 2050s, and 4.6 ± 0.4 °C in the 2080s and the models show high uncertainty in projections of future winter and summer precipitation. Future annual warming across Africa is projected to range from 0.2 °C per decade to more than 0.5 °C per decade, while future changes in mean seasonal rainfall in Africa are less well defined. In Latin America, projections indicate a slight increase in temperature and changes in precipitation.

Impacts of climate variability and changes are discussed with suitable examples. Agricultural productivity in tropical Asia is sensitive not only to temperature increases, but also to changes in the nature and characteristics of monsoon. Simulations of the impacts of climate change using crop simulation models show that crop yield decreases due to climate change could have serious impacts on food security in tropical Asia. Climate change is likely to cause environmental and social stress in many of Asia's rangelands and drylands. In the arid and semi-arid tropics of Africa, which are already having difficulty coping with environmental stress, climate change resulting in increased frequencies of drought poses the greatest risk to agriculture. Impacts were described as those related to projected temperature increases, the possible consequences to water balance of the combination of enhanced temperatures and changes in precipitation and sensitivity of different crops/cropping systems to projected changes. In Latin America, agriculture and water resources are most affected through the impact of extreme temperatures (excessive heat, frost) and the changes in rainfall (droughts, flooding). Adaptation potential in the arid and semi-arid tropics of Asia, Africa and Latin America was described using suitable examples. It is emphasized that approaches need to be prescriptive and dynamic, rather than descriptive and static.

Climatic Change (2005) 70: 31-72

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