The impact of climate change on agriculture
Under the project Clima@EduMedia, the Escola Básica e Secundária da Sé (Middle School and High School) interviewed the researcher Aureliano Malheiro, of the Centre for the Research and Technology of Agro-Environmental and Biological Sciences at the University of Trás-os-Montes and Alto Douro (CITAB / UTAD) about the impact of climate change on agriculture.
Em Revista (ER) – In your opinion, as an expert, how can Portuguese agriculture be affected by climate change?
Aureliano Malheiro (AM) – Portuguese agriculture will certainly resent climate change (not to be confused with the concept of climate variability), given that climate models project, for the present century, an increase in air temperature, a decrease in precipitation (with consequent reduction in the soil moisture) and an increase in the number and severity of draughts and heat waves. It should be noted that plants are extremely sensitive to environmental conditions, especially temperature. These changes at a climate level are likely to have significant effects on the growth and development of plants and ergo the productivity and product quality (fruit, wine, etc.). In fact, extreme weather events (such as hail, sleet, waterspout) can cause substantial losses in production and quality, while climate change may, for example, anticipate the phenological cycle and, consequently, the harvest, promote the emergence of new and/ or enhance current pests / diseases or increase inter-annual variability of productivity and quality.
ER – In our area, rich in vineyards, cherry and apple trees, will these changes have an equal or superior impact than in other regions of the country?
AM – The impact will be greater in inland and lower altitude areas (usually warmer and drier) compared to coastal and higher altitude regions. However, it may be variable even within a small area like the Alto Douro. For example, the designated sub-region of Baixo Corgo (which includes Lamego) should see lower phytosanitary problems, but in warmer areas like the Alto Douro, climate change could lead to unbalanced wines with undesirable characteristics (herbaceous flavours, alcohol content too high). Impacts also depend on the adaptation measures implemented, such as the choice of varieties that are more tolerant to dryness, proper management of the foliage area according to each plant, irrigation use, etc.
ER – How might the consequences caused by these changes affect the regional economy?
AM – As I’ve mentioned, when necessary, these adaptation measures have costs that can be high. On the other hand, there is a risk of altering the specificity of the products produced in the region, either by introducing different agronomic techniques, either by the differential response of the plant to the most severe weather conditions.
“Each of us should contribute to reduce carbon dioxide emissions"
ER – In your opinion, what could be the solution to these problems? And we young people, what can we do to help?
AM – The answer to this problem, as mentioned, fundamentally involves the implementation of adaptation measures (assuming that climate change is happening) and mitigation measures, that is, each of us should contribute, where possible, to reduce carbon dioxide emissions by simple acts such as, for instance, walking more instead of driving.
ER – In short, what are the main points regarding the topic of “Climate Change in Agriculture”?
AM – Despite the uncertainties inherent to future climate, in a climate change scenario significant changes in Portuguese agriculture are expected. The projected increase in air temperature may cause a temporary shortening of different growth stages of crops from the beginning of the season until harvest. Thus, for example, the vintage will take place earlier and during a warmer part of the year (August, in Douro).
If, on the one hand, the coastal regions, overall, should have fewer problems with pests and diseases, the negative impacts on the production and quality should overlap, due to the disastrous rise of the cumulative effects of water stress (excessive dryness) and heat, particularly in the south. On the other hand, these changes become crucial to adaptation, whether short-termed (such as the use of photo-thermo-protective agents of leaves and/ or the implantation of irrigation) or long term (e.g., Rootstock selection and varieties adapted to dryness, crops planted at a higher altitude) in order to maintain the current levels of production and quality.
Aureliano Malheiro (AM) – Portuguese agriculture will certainly resent climate change (not to be confused with the concept of climate variability), given that climate models project, for the present century, an increase in air temperature, a decrease in precipitation (with consequent reduction in the soil moisture) and an increase in the number and severity of draughts and heat waves. It should be noted that plants are extremely sensitive to environmental conditions, especially temperature. These changes at a climate level are likely to have significant effects on the growth and development of plants and ergo the productivity and product quality (fruit, wine, etc.). In fact, extreme weather events (such as hail, sleet, waterspout) can cause substantial losses in production and quality, while climate change may, for example, anticipate the phenological cycle and, consequently, the harvest, promote the emergence of new and/ or enhance current pests / diseases or increase inter-annual variability of productivity and quality.
ER – In our area, rich in vineyards, cherry and apple trees, will these changes have an equal or superior impact than in other regions of the country?
AM – The impact will be greater in inland and lower altitude areas (usually warmer and drier) compared to coastal and higher altitude regions. However, it may be variable even within a small area like the Alto Douro. For example, the designated sub-region of Baixo Corgo (which includes Lamego) should see lower phytosanitary problems, but in warmer areas like the Alto Douro, climate change could lead to unbalanced wines with undesirable characteristics (herbaceous flavours, alcohol content too high). Impacts also depend on the adaptation measures implemented, such as the choice of varieties that are more tolerant to dryness, proper management of the foliage area according to each plant, irrigation use, etc.
ER – How might the consequences caused by these changes affect the regional economy?
AM – As I’ve mentioned, when necessary, these adaptation measures have costs that can be high. On the other hand, there is a risk of altering the specificity of the products produced in the region, either by introducing different agronomic techniques, either by the differential response of the plant to the most severe weather conditions.
“Each of us should contribute to reduce carbon dioxide emissions"
ER – In your opinion, what could be the solution to these problems? And we young people, what can we do to help?
AM – The answer to this problem, as mentioned, fundamentally involves the implementation of adaptation measures (assuming that climate change is happening) and mitigation measures, that is, each of us should contribute, where possible, to reduce carbon dioxide emissions by simple acts such as, for instance, walking more instead of driving.
ER – In short, what are the main points regarding the topic of “Climate Change in Agriculture”?
AM – Despite the uncertainties inherent to future climate, in a climate change scenario significant changes in Portuguese agriculture are expected. The projected increase in air temperature may cause a temporary shortening of different growth stages of crops from the beginning of the season until harvest. Thus, for example, the vintage will take place earlier and during a warmer part of the year (August, in Douro).
If, on the one hand, the coastal regions, overall, should have fewer problems with pests and diseases, the negative impacts on the production and quality should overlap, due to the disastrous rise of the cumulative effects of water stress (excessive dryness) and heat, particularly in the south. On the other hand, these changes become crucial to adaptation, whether short-termed (such as the use of photo-thermo-protective agents of leaves and/ or the implantation of irrigation) or long term (e.g., Rootstock selection and varieties adapted to dryness, crops planted at a higher altitude) in order to maintain the current levels of production and quality.
Work by: Ângela Pereira e Gonçalo Ferreira
10th Grade
Escola Básica e Secundária da Sé (Middle School and High School)
Attention: The phenological cycle refers to the number of phenomena, such as flowering, migration and mating, which can be affected by weather and other environmental factors.
This work was carried out under the Flash Seminar held on the 17th and the 24th of April 2015 and the 8th of May at Escola Básica e Secundária da Sé (Middle School and High School), in Lamego.
10th Grade
Escola Básica e Secundária da Sé (Middle School and High School)
Attention: The phenological cycle refers to the number of phenomena, such as flowering, migration and mating, which can be affected by weather and other environmental factors.
This work was carried out under the Flash Seminar held on the 17th and the 24th of April 2015 and the 8th of May at Escola Básica e Secundária da Sé (Middle School and High School), in Lamego.