Impacts

In the next 40 years, several different models predict an increasing water shortage for annual crops. Beyond the effects on ecosystems, a decrease in potential production for all crops must be anticipated as a consequence of water shortage. In terms of biodiversity, a 2009 report by the European Environment Agency notes the potentially catastrophic effects of global warming on endemic mountain species. By way of example, since 1990, meadow butterfly populations have sharply declined throughout Europe. The report predicts that by the end of the 21st century, 60% of mountain plant species will be in danger of extinction. These species will no longer be able to move or find identical climate conditions (confined species and shrinking habitat).

Finally, in the mountains, numerous natural hazards will become more likely because of climate change. Changes in rainfall patterns, coupled with air and soil temperature variation, will be the cause for increased flooding and mud rains, landslides, glacier hazards, and forest fires…. For all these reasons, the frequency of natural hazards is expected to increase.

In the next 40 years, different models predict an increasing water shortage for annual crops, followed by a decrease in 2070. As a consequence of the water shortage, a reduction in potential production for all crops can be expected.
With regard to snowfall, the number of days snow cover exceeded 0 cm fell an average of 10 days in 1971-2008. Meanwhile, the number of days with more than 30 cm has fallen 15 days.

Rising temperatures and the consequent transformation of snowfall into rain would directly impact runoff and high-altitude water storage, and therefore, the water levels replenished in summer. These changes would most certainly affect mountain environments as well as regions located further downstream.

Climate change would lead to new irrigation needs. An increase in irrigation needs for vineyards is expected throughout regions until 2020, even with water saving strategies in place. Increasing water shortage in the future may also mean significant irrigation will be necessary to ensure continued forage production. In this way, by 2070, an average of 100 mm of irrigation water will be needed to cover 80% of water needs for typical grassland soil.

To read more about the impact on water sources, download this document in French, Spanish, and English.

The 2009 report by the European Environment Agency notes the potentially catastrophic effects of global warming on endemic mountain species. By way of example, since 1990, meadow butterfly populations have sharply declined throughout Europe. The report predicts that by the end of the 21st century, 60% of mountain plant species will be in danger of extinction. These species will no longer be able to move or find identical climate conditions (confined species and shrinking habitat).

The most notable change the mountain forest will undergo in response to climate change is the shifting of plant cover to higher mountain altitudes. For more than 30 years, forest species have shifted up mountain at a rate of 3 metres per year.
In addition to transforming the mountain landscape, vegetation shift causes conflicts in terms of use. Gradually, the forest will reach mountain pastures used for grazing. This shift in search of more suitable habitat, which has been confirmed by scientists, will consequently change the distribution of species throughout the Pyrenees mountain regions.

Furthermore, soil desiccation-linked to water stress caused by a global rise in temperatures-is an important factor in the general decline of forests on steep terrain. Problems could consequently arise for local mountain populations since these forests generally protect against erosion and landslides.
On the other hand, another consequence of generalised soil desiccation is increasing risk of forest fires throughout the range. So far, this risk has been avoided.

Finally, rising temperatures and a precipitation shortage, predicted by climate models, causes a water stress that particularly targets forests, especially conifer species less adapted to drought conditions. Increasing water shortage during growth periods will provoke a sharp decline in water replenishment for the area (-125mm/year from now until 2025) and a decrease in average production of about 12%, more moderate at higher altitudes (-0,5tMS*/ha/year from now until 2025).

To read more about the impact on biodiversity and the forest, download this document in French, Spanish, and English.

Numerous natural hazards associated with mountain environments could be affected by climate change. Climate change would cause new trends in climate averages and extremes. It even seems the future will bring an increase in climate variability in terms of both extremely high and low temperatures.

It is likely that global warming will destabilise the permafrost thermal regime, consequently increasing the instability of mountain slopes. In fact, this type of thaw could modify hydrological conditions in the network of rock cracks, thereby destabilising rock walls. Morraines, etc., which contain ice, lose cohesion upon thaw, causing landslides. In general terms, soils would become increasingly unstable with the disappearance of permafrost. In addition, building foundations, cable cars, and ski lifts could be directly affected and damaged by the underground settling associated with ice melt.

Although the annual volume is slightly down, rainfall could appreciably increase in winter and summers would be drier and warmer. As a consequence, pastureland soil and forests will dry up considerably, making them more vulnerable to erosion and gravitational forces.

In addition, snow cover patterns affect avalanches. In winter, among other conditions, low temperatures are required to produce avalanches; in this sense, the risk would not increase. Conversely, spring avalanches (wet snow) may occur with more frequency, but the trajectory of their flows is easier to predict. In either case, the occurrence of these events is essentially influenced by the interannual variability of weather conditions.

In addition, on the mountain, in areas where a Mediterranean or transforming climate predominates, increased risk of forest fire could lead to a greater percentage of stripped soil, and consequently, more erosion risk.

To read more about the impact on natural hazards, download this document in French, Spanish, and English.

Temperature is the driving force behind the growth of all cultivated species: in the face of increased temperatures due to global warming, the anticipation of phenological studies is quite significant (wheat, maize, rapeseed, sunflower, sorghum, grapes). It is very influential for farmer’s choices in terms of technique and the ecophysiological behavior of crops that will experience a widening gap between growth phases and environmental constraints (Gate and Bresson, 2010).
But climate change will also have consequences on other economic sectors aside from agriculture, including tourism. If the Pyrenees Mountains are XX% dependent on tourism, these socioeconomic impacts will be extremely important.

Temperature is the driving force behind the growth of all cultivated species: in the face of increased temperatures due to global warming, the anticipation of phenological studies is quite significant (wheat, maize, rapeseed, sunflower, sorghum, grapes). It is very influential for farmer’s choices in terms of technique and the ecophysiological behavior of crops that will experience a widening gap between growth phases and environmental constraints (Gate and Bresson, 2010).

By 2050, harvest times are expected to move up 8–16 days for wheat and rapeseed and 25–41 days for maize (without varying the planting date), especially in the North. As for spring crops, the growth period will be reduced 10–20 days for maize and 8 days for sunflower, which will be detrimental to the harvest. As for grapevines, as flowering occurs earlier, the maturation period shortens; both of these occurences are more serious in the case of vine than maize. For winter crops, cycles are expected move up and phase length to shorten slightly; and for spring crops, cycles will move up at the same time that growth phases shorten considerably.
Future climate scenarios already expect irrigation needs to increase by approximately 10% for certain crops. And climate change will likewise impact the development and severity of certain diseases.

Although rising temperatures might create new farming opportunities in areas where it has previously been too cold to plant, the periods between crops will lengthen in areas that are currently farmed (because annual harvest dates move up) or crop rotation will become more prevelant (Levrault, 2010).

To read more about the impact on the agricultural sector, download this document in French, Spanish, and English.

Climate change also means the risk of impacts on pastoralism, a sector which could undergo significant alterations.

As a result of various changes, ranchers have observed direct effects on their herds, including an approximate 50% decline in average cattle weight (between 1994-2002 and 2003-2006).

Although winter and summer grazing activities are very different, the former takes place in stables and the second in mountain pastures, they are closely linked: winter feeding depends on forage yield and the summer grass production levels in mountain pastures largely depends on snow cover and melt – because snow melt nourishes the vegetative stage and therefore the ability to feed animals. So it is of great concern that these two parameters, snow cover and melt, be affected by climate change, as seen above.

In the Alps, the Isère Alpine Pasture Federation is already observing these effects on summer productivity, in three stages, and it is reasonable to consider this same phenomenon valid for other mountain areas.

Firstly, ranchers confirm that the summer season begins earlier, given the advance of the thaw. The prolongation of the summer period has been observed for several years: 10 days longer at 500 m and 14 days longer at 1,500 m.

Because of the early thaw, plants resort to soil reserves sooner and sooner–especially water reserves–which may be detrimental for the second stage that happens mid-summer. Becuase they may be subjected to water stress, there is the risk that pastures may not produce enough grass to feed the herds. Therefore, it may be necessary to bring in external sources of water and forage, thereby reducing stocks usually reserved for the winter period.

Finally, although the period is long enough for grass to sprout a second time, it happens later. Potential productivity at this time is limited by different factors, such as little sunlight and lower temperatures.

Source: www.sig-pyrenees.net

Today, the long-term future of ski resorts is uncertain. In fact, projected climate change even throws into question the longevity of its core business, which requires minimal snowfall distributed over several winter months.
There are fears that global warming will make it impossible to ensure skiing throughout much skiable terrain. As a consequence, jobs in this sector would be put at risk.

On a global level, mid-mountain ski stations would be most vulnerable to changes in snow cover, and some may not even reach the critical threshold to open for the season. Several scientific studies show that above 1,500 m, an average rise of 2 ºC in the Pyrenees would result in a decrease in the number of days of snow cover equal to one month (30–49 days/year). This trend would be especially noticeable in the central and western Spanish Pyrenees.

Specifically, if the number of months with snow cover falls from 3 to 2, and the limit of good ski conditions worsens 150 m with each rising degree, mid-mountain ski stations would stand to lose one quarter of their turnover.

In addition, climate change would have direct consequences for tourist resorts. During the summer, climate change could extend the season and allow tourism to shift to the north (or higher altitudes). Lower-altitude areas of the Mediterranean would have to receive populations prepared to withstand extreme heat; although higher temperatures might suppose that senior citizens and residents of the French, Italian, or Spanish Mediterranean may choose not to visit these areas. As a result, the mid-mountain may become a favourite destination for tourists looking for relatively cool temperatures, shady forests, etc. Rising temperatures would equally affect inland and coastal areas, which could improve the tourism potential of the mid-mountain.

In general, the range of tourism possibilities between seasons would be widely increased.

To read more about the impact on tourism, download this document in French, Spanish, and English.