Abstract: The increase of emissions of green house gases is changing the global climate. In most areas of the world, temperature will go on increasing, rainfall patterns will be distorted, absolute humidity will rise, and extreme weather events will be likely more frequent and severe. However, the projections that have been published show that the climates of the various geographical areas are affected differently. In general, as far as crop performance is concerned, lower latitudes get the most pernicious effects and higher latitudes tend to have little or no crop loss. Increased carbon dioxide concentration and some of the changes on weather elements will influence crop development and growth in a simple way, but other repercussions are more difficult to grasp.
Increased carbon dioxide concentration in the air augments photosynthetic rate, mainly of C3 plants. Air temperature increases favour plant development and growth under colder conditions, but may reduce plant performance in warmer areas. Higher temperatures may favour the development of pests and diseases. Increases in winter temperature may lead to inadaptation of crops, mainly deciduous tree crops, that require chilling before new leaves and flowers are formed. Increases in summer temperature may lead to heat stress of some crops or varieties. Concentration of rainfall, that is likely to occur in many areas, will alter the soil water balance. These changes may occur seasonally or throughout the year, but they will mean less water available for crops and natural vegetation. This means that water availability for crop production is likely to decrease in many areas where irrigation is necessary and rainfed production is already vulnerable to natural climate variability. It may therefore result in the need for changing crop patterns or to adopt different crop varieties, and to use different cropping techniques, including changes in planting dates.
This presentation undergoes a comprehensive discussion of all these aspects, taking a quantitative perspective, that includes the exhibition of results of simulations, under different scenarios.


Brief Biography of the Speaker:
Professor Jose Paulo Mourao de Melo e Abreu is Associate Professor w/ Habilitation in the Instituto Superior de Agronomia, The Technical University of Lisbon, and has undertaken researched in the areas of Global Change, Agrometeorology and Modelling in Horticulture and Agriculture. Published about eighty publications, including two FAO books, and delivered about fifty invited talks in Portugal and abroad. Developed twelve models.
He is the national representative of Portugal in the European Society for Agronomy, is a referee of about twenty international journals and has organized three international meetings. Has been responsible for six research projects, including two international, and cooperated in many others.