How climate change affects agriculture in Alentejo
On the 12th of May 2015, at Escola Secundária de Vendas Novas (High School), 12th grade students of Science and Technology interviewed Professor João Andrade Santos, an expert on climate change and agriculture and researcher at the Centre for the Research and Technology of Agro-Environmental and Biological Sciences at the University of Trás-os-Montes and Alto Douro, in order to obtain information on the impact of climate change on agriculture.
In recent decades, in our country, climate change has come to be considered a major threat both for today's society and for future generations. As Professor João Santos mentions, “some regions of our country will be much drier and warmer than they are today.” Such changes may affect domestic agriculture, and more specifically the Alentejo region, one of the most affected by climate change. Data from the The Portuguese Sea and Atmosphere Institute (Instituto Português do Mar e da Atmosfera- IPMA) - indicate that the maximum annual rainfall of 100-150mm declined to 50-100mm between March 2001 and April 2015, resulting in an increase of roughly 2°C in average temperature between April 2001 and April 2015. According to Professor João Santos, combining these two effects we will have on the one hand, an increase in water stress of plants because there will be less water available in soils, and this means that the plants have greater water stress problems. On the other, together with water stress, we will also have thermal stress. The two, combined, will have a very significant impact on the physiological development of plants, in its phenology, growth stages, i.e. grapevines during flowering stage, during "painter" phase, in which the grapes start maturing or during harvest. As our interviewee explains, "all these dates will be changed. Moreover, the physiological development of the plant will be much altered and this will consequently change the chemical compounds of the fruit. Therefore, climate change will be felt via heat and water stress, but also in the chemical composition of the agricultural products, their amounts and dates of production". According to the professor, it is very difficult to say what impact these changes will have on the national economy, because the current climate models are very complicated and depend on many different variables, such as the atmosphere, the oceans, the biosphere, the lithosphere, the cryosphere, etc. In other words, it involves all systems and interactions of our planet. It can therefore be concluded that, depending on the scenario (much worse or slightly grievous), the impact on the economy will be larger or smaller. |
The increase in environmental temperature will inevitably result in a more intense need of soil irrigation, which, due to water shortage, will become unsustainable. To prevent this from happening it will be necessary to adopt cultures from warmer climates that require less water.
Alentejo is the hottest Portuguese region, and crops from warmer climates are already being produced, for example Sirah variety, from North Africa, is being cultivated in Alentejo, resulting in a change in the type of wine Alentejo can produce. But for the Alentejo region to receive new cultures from warmer climates, it is necessary for some Mediterranean crops to be lost. Those crops that will be lost depend on the availability of water at the time. In the opinion of Professor João Santos, “in the future almost all Mediterranean crops that are now cultivated in Alentejo will be lost and replaced with more tropical crops, except for the olive grove, the cork oak tree, the holm oak, which are species that are already half adapted to the hot climate of the region.” So, according to Professor João Santos, the ideal for the future would be “to continue to invest in oil, in cork and wine, though the latter with some changes. Also, a good investment for the future would include the area of genetics, because through artificial selection and genetic modification we can obtain variations of species now growing in Alentejo, though more resistant to heat and water shortage. It is not feasible to bet on new cultures because there is a lot of competition with other countries that already possess the adequate climate to produce these crops, thus leading our country to suffer considerable losses.” |
Work by: Daniel Gonçalves, João Pacheco, Miguel Morais, Pedro Remédios and Vasco Saltão
12th Grade
Inter-School Group of Vendas Novas (Agrupamento de Escolas de Vendas Novas)
Erratum:
No 1: Precipitation reduction does not result in an increase in temperature. The two phenomena can occur simultaneously in a given region, but less rainfall does not lead to temperature rise.
No 2: The correct designation for the temperature units is degree Celsius; not centigrade degrees. The symbol must be oC; and not ºC.
This work was carried out under the Flash Seminar held on the 5th and 12th of May at the Inter-School Group of Vendas Novas (Agrupamento de Escolas de Vendas Novas). Students developed media content based on interviews with experts in various fields related to climate change and research on the subject.
12th Grade
Inter-School Group of Vendas Novas (Agrupamento de Escolas de Vendas Novas)
Erratum:
No 1: Precipitation reduction does not result in an increase in temperature. The two phenomena can occur simultaneously in a given region, but less rainfall does not lead to temperature rise.
No 2: The correct designation for the temperature units is degree Celsius; not centigrade degrees. The symbol must be oC; and not ºC.
This work was carried out under the Flash Seminar held on the 5th and 12th of May at the Inter-School Group of Vendas Novas (Agrupamento de Escolas de Vendas Novas). Students developed media content based on interviews with experts in various fields related to climate change and research on the subject.