IEMed Mediterranean Yearbook 2007

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Climate Change in the Mediterranean

Mar Asunción

Head of the Climate Change Programme
WWF Spain, Madrid

Due to its geographical location, the Mediterranean region is one of the areas in the world that is most vulnerable to climate change. A 2ºC rise in global temperature will most likely bring about a warmer, more variable climate in the Mediterranean region, with an increase in water scarcity, particularly in the summer, more forest fires, a decrease in crops, a drop in tourism and the extinction of species.

Climate change is a reality that even the most sceptical would not dare to question. Since the beginning of the 21st century, we have endured extreme climatic events more frequently and with greater intensity. For the first time a hurricane—Hurricane Vince—reached the Mediterranean region and landed in the southwestern coast of Spain. Tropical storm Delta then hit the Canary Islands causing severe damage. A significant trend has been observed in the increase in droughts in the Mediterranean and Sahel. Beyond our borders, the greater frequency and intensity of hurricanes in the Gulf of Mexico—twice as many as there were 30 years ago—left with it a trail of destruction and death.

It is thus not an isolated phenomenon but rather the culmination of a trend that has been occurring in recent years and about which scientists have been warning us for more than twenty years.

Climate Change

History of life on Earth goes back approximately 3,800 million years and humanity is a very recent guest, appearing at the end of the last million years. If we were to use a fast camera capable of compressing time since the Earth was formed—some 4,500 million years ago—into a one-year period, we would see that man appears ten minutes before the end of the year and the industrial revolution and our technological era would appear in the last 13 seconds. However, in such a short period of time we have deeply affected the system that sustains us, to the extent that we are even changing the climate.

The alterations we are inflicting upon the Earth in such a short period of time are producing an impact with catastrophic consequences for human populations. Extreme climatic events are increasing in frequency and severity and scientists are warning us that if we do not implement urgent measures we may find ourselves heading down an irreversible path of much more drastic changes with even greater catastrophic consequences, particularly if the increase in the planet’s global temperature is more than 2ºC above pre-industrial temperatures.

However, the consequences of climate change become apparent in different parts of the planet in different ways, poor countries being more vulnerable and less responsible for the problem

We are releasing enormous amounts of CO2 into the atmosphere by burning fossil fuels—coal, petrol and gas—for the production and use of energy. CO2 is the main gas responsible for the greenhouse effect, that is, it “traps” heat in the atmosphere and produces a rise in the planet’s global temperature, 0.7ºC in the last century, the highest rise in 10,000 years.

However, the consequences of climate change become apparent in different parts of the planet in different ways, poor countries being more vulnerable and less responsible for the problem.

Impact of Climate Change in the Mediterranean

The physiognomy of the Mediterranean region is a combination of its geographical conditions and culture that has adapted to these conditions over centuries for its development. The Mediterranean’s resources are inseparably linked to its climatic characteristics. A hot and dry summer climate combined with 45,000 km of coastline has turned the region into a leading tourist destination, attracting 30% of world tourism. Hot summers and mild, rainy winters have enabled agriculture to develop as an integral part of the region’s economy. Furthermore, around one hundred million hectares of woodland cover the entire Mediterranean basin, supporting a considerable biodiversity.

Today, this natural wealth is under significant pressure—from population and the current development model—that climate change could make even worse. To learn the impact of global warming in the Mediterranean, WWF commissioned a study to a team of scientists from the region—Christos Giannakopoulos, Marco Bindi and Tina Tin—with the aim of finding out how the Mediterranean region’s climate would change if global temperature rose 2ºC over pre-industrial temperatures, and determining the impact on water resources, forest fires and biodiversity, as well as on the region’s main economic sectors: agriculture and tourism.

The analysis is based on the global climate model of the Hadley Centre in the United Kingdom and on the A2 and B2 emission scenarios of the Intergovernmental Panel on Climate Change (IPCC). It has also considered climate information based on temperature, precipitation and wind. The study focuses on the period between 2031-2060, when global temperature is expected to reach 2ºC above pre-industrial levels.

This warmer, drier and more variable climate will probably bring with it increased fire risk, lower agricultural yields, changes in tourist seasons, a rise in water demand and loss of species

It then goes on to summarise the main impacts that a 2ºC rise in global temperature are likely to have on the Mediterranean region:

Heat waves With a 2ºC rise in global average temperature over pre-industrial levels, the climate in the Mediterranean region will be warmer, drier and more variable. The annual average temperature in the region could increase by 1-2ºC over current conditions. However, inland in countries such as Turkey, northern Italy and the Maghreb, far from the moderating effect of the sea, maximum temperatures could rise up to 5ºC. Heat waves and extremely hot days are expected to increase, especially in inland areas, but even the north Aegean islands, with their sea breeze, are expected to endure two more weeks of heat waves a year.

Decreased rainfall Annual precipitation is likely to decrease up to a fifth in the southern Mediterranean, while summer rainfall in the northern Mediterranean may decrease over 30%. The study suggests that there will be a shift in drought periods and that they will last longer. The number of dry days will increase and rainfall is likely to be concentrated in short periods of time, which may lead to storms in Italy, western Greece, the south of France and the north-western part of the Iberian Peninsula.

This warmer, drier and more variable climate will probably bring with it increased fire risk, lower agricultural yields, changes in tourist seasons, a rise in water demand and loss of species.

Fires A 2ºC global warming will lead to a greater risk of forest fires practically throughout the year in the southern Mediterranean. In almost the entirety of the rest of the region, the fire risk period is expected to be an additional one to six weeks. Extreme fire risk will probably increase an additional month in the Iberian Peninsula, northern Italy and the Balkans, putting greater pressure on local nature, including various species of animals that are already in danger of extinction.

Agriculture A hotter and drier climate will also lead to a decrease in agricultural yields, particularly in summer crops that are not irrigated. Beans, soybeans and lentils are among the most affected crops in the region, with an up to 40% drop in yields, depending on the location. The impacts are not evenly distributed: The decrease in yields will be more severe in the south than in the north of the Mediterranean. Throughout the region, agricultural strategies could generate an increase in crop yields that are more resistant to the warmer and drier climate. However, such strategies could require up to 40% more water for irrigation, which may not always be available with a 2ºC warming.

It is frequently said that the measures to combat climate change have a cost, but that not taking them has even greater costs

Tourism A greater frequency in heat waves and droughts will probably discourage summer holidays in the Mediterranean region. Tourists may prefer to bring forward or delay their summer holidays or even decide to go elsewhere. The possible reactions of the tourism industry would be to discourage Mediterranean summer holidays and try to make it a destination in spring and autumn.

Water A drier climate with reduced rainfall and surface runoff, and a rise in demand from the agricultural sector, will worsen the already high level of water stress in the region. A 1ºC increase in temperature could lead to a reduction of 5 -14% in water yields in Spain, while a similar rise in Algeria would probably lead to a water demand that exceeds available water resources by 800 million m3.

Heating and cooling As is to be expected, heating requirements will probably decrease in the north. However, cooling needs will increase in other parts of the region, especially in the south. In the south of the Iberian Peninsula and along the entire southern Mediterranean coast to Syria, an additional month of heavy cooling will be required. With increasingly dry years, there will be less hydroelectric energy available and the problem will worsen if the energy deficit is covered with fossil fuels.

Biodiversity Studies warn us that a 3.6ºC warming could lead to a loss of over 50% of plant species in the northern Mediterranean, with a loss of over 80% in northcentral Spain and in the mountains, particularly in France. A greater fire risk as a result of a warmer and drier climate will also encourage the spread of invasive grass species, which in turn could lead to more frequent and more intense fires.

Health Climate change has a direct and indirect impact on human health. A shorter period of frost and a longer warmer period would bring about an expansion of infections that are transmitted by animal vectors, such as malaria and dengue, which are transmitted by mosquitoes and require specific temperature and humidity conditions to survive. A rise in temperatures also accentuates other illnesses such as allergies, which are a consequence of an increase in pollen and spore concentrations.

Today’s Actions Determine Tomorrow’s Climate

The good news is that we are still in time to mitigate this important problem. To do so, it is essential and urgent to decrease emissions and set up adaptation measures to avoid the worst consequences of climate change. It is very important to keep global temperature below the 2ºC rise since pre-industrial levels, which requires: industrialised countries to comply with their commitments under the Kyoto Protocol and adopt reductions of around 30% by 2020 and 80% by 2050; developing countries to control their emissions and directly adopt clean technologies with the help of wealthy countries, which must transfer technologies and resources; the replacement of the current energy model that is greatly responsible for greenhouse gas emissions that cause climate change.

The Cost of Not Taking Measures Will Be Even Greater

It is frequently said that the measures to combat climate change have a cost, but that not taking them has even greater costs, both in economic terms and in loss of human lives. The Stern report, published in October 2006, reached the conclusion that the cost of inaction could be 5 -20% of the annual global GDP, while acting could limit such a cost to 1%. It also warns that a delay in implementing measures increases the both the danger and the cost.

References

Giannakopoulos, C., Bindi M., Tin, T: “Climate change in the Mediterranean Region resulting from a 2º degree global temperature rise”. WWF, Gland (Switzerland), 2005.