Effects on forestry, agriculture and buildings

Air pollution and effects on forestry

Most climate scenarios point to warmer, more humid weather in the northern parts of Europe, with a consequential increase in forest growth. In central and southern Europe, however, the temperature rise is likely to be combined with a sharp reduction in rainfall, which would be a major problem for the existing forestry industry.

The availability of nutrients may increase, since decomposition will speed up if the climate gets warmer. Nutrients will circulate faster, and this could support increased production.

Another way that air pollution can promote growth in some parts of Europe is through the fallout of nitrogen. The deposition of nitrogen serves to fertilize the forest and could therefore promote forest growth. On the other hand, too much nitrogen input could bring negative effects. Fallout over parts of Europe still amounts to several tens of kilograms of nitrogen per hectare each year.

Air pollution also has a number of major drawbacks for the forestry industry:

Some species of trees do not like warmer weather.

Many forest pests - especially insects and fungi - are favoured by a warmer and more humid climate.

Acid fallout acidifies the soil and, among other things, reduces the availability of important nutrients for trees. It also slows down decomposition.

Ground-level ozone damages plants.

Air pollution and agriculture

A crucial issue for agriculture worldwide is the availability of water. For instance, availability in summer is expected to fall in central areas of continental Europe and around the Mediterranean as a result of the enhanced greenhouse effect. The climate in already dry areas of southern Spain may become almost desert-like.

Conditions for farming may change drastically in many parts of the world, resulting in food shortages and social problems.

In northern Europe it is likely that agricultural yields will rise - the growing season may be extended by a few months and precipitation can be expected to increase. On the negative side, however, the higher temperatures could also lead to increased attacks by insects and fungi.

Ozone is probably the pollutant that causes the largest harvest losses in agriculture today. It has been estimated that today's levels could give rise to annual harvest losses worth over 3 billion euros in the EU28.

Air pollution speeds up corrosion

The effects of wind and weather naturally mean that all materials will decay sooner or later, but air pollution speeds up this process. Buildings, vehicles, metal structures, statues, rock carvings, museum artefacts, water pipes, electrical cables etc., are all attacked and damaged. Objects made of limestone and some types of sandstone are especially vulnerable to acid substances, but not even the hardest granite can resist entirely.

The greatest damage is caused by sulphur dioxide, which is corrosive in both gaseous form and when converted into sulphuric acid.

Nitrogen oxides also contribute to the damage, partly through the formation of corrosive nitric acid, and partly by reinforcing the damaging effects of sulphur dioxide.

Ozone and other oxidants react readily with organic substances. They contribute mainly to the breakdown of textiles, leather and rubber. As a result of its oxidizing ability ozone can also increase the corrosiveness of compounds of sulphur and nitrogen oxides.

Major economic losses are caused by the acceleration of corrosion due to air pollution. The annual damage to modern buildings and materials in EU28 was estimated at 1 billion euros in 2010. Added to this is the extensive and serious damage caused to our cultural heritage, which in many cases is impossible to repair or measure in economic terms.

In northern Europe this corrosion has decreased markedly during the 1990s, thanks to reduced emissions of acidifying substances. However, it is still estimated that corrosion over large parts of Europe is at least twice as rapid as the natural background rate.