6
H.-J. Bolle
In December 324 mm of rain were recorded within 2 days in Campania, east of
Naples. In the South-East it was again dry. Cyprus experienced the 5 th consecutive
year below normal precipitation. Israel reported one of the hottest summer of the last
century (1998 was the record with even one degree more in Bet Dagan) and, as in
1958/9, one of the driest September to December periods. In the Southeast of Spain
and the Balearic Islands the year 1999 ended with 50% less rain than normal.
Long lasting dry periods during summer 2000 caused severe stress on plants,
fostered wild fires in many places, and led to losses in harvests. Following the dry
period in a number of places such as at the east coast of Spain, the south coast of
France and northern and middle Italy long term rainy periods occurred during late
autumn and winter 2000/1 with partially disastrous torrential rains causing flash
floods and land-slides which killed people, destroyed houses, eroded fertile soil, and
obstructed farmers to bring out seed at the right time. Venice had "aqua alta" the
first time for several weeks continuously.
The sequence of extreme events continued in 200 I. In Italy the dry period lasted
from early summer to winter 2001/02. As a consequence of the dryness and the
permanent inversion situation the pollution in all major Italian cities reached
extremely high values so that traffic had drastically to be reduced. After a long dry
summer torrential rainfall occurred in November in Algeria. Nearly 400 people
were killed and terrible destructions were caused in Algiers. Strong storms crossed
Spain and caused became especially strong over Balearic Islands. The East in
January 2002 suffered from a very cold spell that brought snow to Crete with severe
frost damages.
Extreme events always happen from time to time but their intensity and
frequency seem to increase during the last decennium. Apparently these extreme
meteorological events were regionally as well as temporarily irregularly distributed.
It is difficult to detect the pattern and to identify the "driving force behind the
scene".
Is this a scenario to which the region has to get accustomed to in the future? Are
these events a regional manifestation of a global climate change? Do they indicate
an instability of the climate, maybe a transient state, or are they merely statistical
excursions? This to know is important for future planning because preventive
measures would be different in the different cases. In view of the most recent new
and alarming IPCC assessment the question can even be aggravated: Will the
amplitude and frequency of extreme climatic events be further enhanced in the
future or will a general trend lead to a different "Mediterranean climate" within
this century ?
To clarify the situation, it has to be asked for the causes of these events. The
connections between the regional impacts and the large scale changes have to be
analysed and the question has to be answered, how economical and ecological losses
due to climate change respectively increased climate variability can be reduced.
These "natural disasters" are intimately interwoven with man's actions on land. In
fact some of the impact of torrential rains can only be understood because of the
transformation of the land surfaces in the Mediterranean area has a long history and
led to deforested, over-exploited and in some regions overpopulated landscapes
H.-J. Bolle
In December 324 mm of rain were recorded within 2 days in Campania, east of
Naples. In the South-East it was again dry. Cyprus experienced the 5 th consecutive
year below normal precipitation. Israel reported one of the hottest summer of the last
century (1998 was the record with even one degree more in Bet Dagan) and, as in
1958/9, one of the driest September to December periods. In the Southeast of Spain
and the Balearic Islands the year 1999 ended with 50% less rain than normal.
Long lasting dry periods during summer 2000 caused severe stress on plants,
fostered wild fires in many places, and led to losses in harvests. Following the dry
period in a number of places such as at the east coast of Spain, the south coast of
France and northern and middle Italy long term rainy periods occurred during late
autumn and winter 2000/1 with partially disastrous torrential rains causing flash
floods and land-slides which killed people, destroyed houses, eroded fertile soil, and
obstructed farmers to bring out seed at the right time. Venice had "aqua alta" the
first time for several weeks continuously.
The sequence of extreme events continued in 200 I. In Italy the dry period lasted
from early summer to winter 2001/02. As a consequence of the dryness and the
permanent inversion situation the pollution in all major Italian cities reached
extremely high values so that traffic had drastically to be reduced. After a long dry
summer torrential rainfall occurred in November in Algeria. Nearly 400 people
were killed and terrible destructions were caused in Algiers. Strong storms crossed
Spain and caused became especially strong over Balearic Islands. The East in
January 2002 suffered from a very cold spell that brought snow to Crete with severe
frost damages.
Extreme events always happen from time to time but their intensity and
frequency seem to increase during the last decennium. Apparently these extreme
meteorological events were regionally as well as temporarily irregularly distributed.
It is difficult to detect the pattern and to identify the "driving force behind the
scene".
Is this a scenario to which the region has to get accustomed to in the future? Are
these events a regional manifestation of a global climate change? Do they indicate
an instability of the climate, maybe a transient state, or are they merely statistical
excursions? This to know is important for future planning because preventive
measures would be different in the different cases. In view of the most recent new
and alarming IPCC assessment the question can even be aggravated: Will the
amplitude and frequency of extreme climatic events be further enhanced in the
future or will a general trend lead to a different "Mediterranean climate" within
this century ?
To clarify the situation, it has to be asked for the causes of these events. The
connections between the regional impacts and the large scale changes have to be
analysed and the question has to be answered, how economical and ecological losses
due to climate change respectively increased climate variability can be reduced.
These "natural disasters" are intimately interwoven with man's actions on land. In
fact some of the impact of torrential rains can only be understood because of the
transformation of the land surfaces in the Mediterranean area has a long history and
led to deforested, over-exploited and in some regions overpopulated landscapes