Air Pollution and Global Change 185
threats has already caused major worries to insurance companies, inter
alia, that will be called to cover the damages.
One consequence that is expected with certainty is the rise of the sea
level, which will be due first to the thermal expansion of water and second to the melting of glaciers. Many mountain and arctic glaciers have
already undergone significant reduction. The ice cap of Antarctica may not
be reduced to a great extent during the first decades of change because of
the increased precipitation (snow) that it will receive in a context of global
warming. Various forecasts for 2030 give a sea level higher by 4–40 cm in
relation to the current one, while the equilibrium level that corresponds
to the doubling of equivalent CO 2 entails probably a greater increase by
100%; this increase, though, will take many decades before it is completed.
On the hypothesis that the phenomenon will continue and that the scenarios that predict the highest temperature increases will be realized, the
repercussions for humanity will be serious, given also that one-third of the
human population lives in a distance of 60 kilometers from the coastal
zones. Flooding of important ports and coastal areas, increase of damages
due to tides and tidal waves, alteration and erosion of coasts, salinization of
the water table, wetlands’ degradation etc. are expected. Dealing with such
hazards requires costly protection measures that—at least for developing
countries—are considered to be infeasible.
The consequences for global agricultural production would also be significant, although the complexity of the phenomena does not allow safe
conclusions. Agriculture is closely adapted to the existing climatic conditions and is extremely vulnerable to climate changes; every significant
change would probably be detrimental. The increased presence of CO 2
in the atmosphere and the increase of rainfall might promote the growth
of some agricultural plants, but also that of parasites. The changes in the
water cycle will intensify the already great problems of desertification
and soil erosion and will bring an extension of the water scarcity zones
with adverse consequences for the agriculture of the respective areas. The
increased frequency of natural disasters, such as heat waves, droughts, fires,
floods, gales etc. will also be a significant adverse factor for agricultural
production. However, the estimations about the results of climatic change
on agriculture are still considered uncertain.
A series of other consequences are considered probable, such as forest
displacement closer to the polar regions, the perturbation of many natural
ecosystems, a greater risk of flooding in cities and industrial areas, degradation of life conditions (heat, humidity, discomfort) in cities with a tropical or
Mediterranean climate, increased energy consumption for air-conditioning
systems and the disablement or operation difficulty of many technical works
(dams, reservoirs, irrigation systems etc.). Our current knowledge about the
greenhouse effect does not allow specific or accurate predictions.
threats has already caused major worries to insurance companies, inter
alia, that will be called to cover the damages.
One consequence that is expected with certainty is the rise of the sea
level, which will be due first to the thermal expansion of water and second to the melting of glaciers. Many mountain and arctic glaciers have
already undergone significant reduction. The ice cap of Antarctica may not
be reduced to a great extent during the first decades of change because of
the increased precipitation (snow) that it will receive in a context of global
warming. Various forecasts for 2030 give a sea level higher by 4–40 cm in
relation to the current one, while the equilibrium level that corresponds
to the doubling of equivalent CO 2 entails probably a greater increase by
100%; this increase, though, will take many decades before it is completed.
On the hypothesis that the phenomenon will continue and that the scenarios that predict the highest temperature increases will be realized, the
repercussions for humanity will be serious, given also that one-third of the
human population lives in a distance of 60 kilometers from the coastal
zones. Flooding of important ports and coastal areas, increase of damages
due to tides and tidal waves, alteration and erosion of coasts, salinization of
the water table, wetlands’ degradation etc. are expected. Dealing with such
hazards requires costly protection measures that—at least for developing
countries—are considered to be infeasible.
The consequences for global agricultural production would also be significant, although the complexity of the phenomena does not allow safe
conclusions. Agriculture is closely adapted to the existing climatic conditions and is extremely vulnerable to climate changes; every significant
change would probably be detrimental. The increased presence of CO 2
in the atmosphere and the increase of rainfall might promote the growth
of some agricultural plants, but also that of parasites. The changes in the
water cycle will intensify the already great problems of desertification
and soil erosion and will bring an extension of the water scarcity zones
with adverse consequences for the agriculture of the respective areas. The
increased frequency of natural disasters, such as heat waves, droughts, fires,
floods, gales etc. will also be a significant adverse factor for agricultural
production. However, the estimations about the results of climatic change
on agriculture are still considered uncertain.
A series of other consequences are considered probable, such as forest
displacement closer to the polar regions, the perturbation of many natural
ecosystems, a greater risk of flooding in cities and industrial areas, degradation of life conditions (heat, humidity, discomfort) in cities with a tropical or
Mediterranean climate, increased energy consumption for air-conditioning
systems and the disablement or operation difficulty of many technical works
(dams, reservoirs, irrigation systems etc.). Our current knowledge about the
greenhouse effect does not allow specific or accurate predictions.