Điều này không có nghĩa là, tuy nhiên một phần là do tính không đồng nhất của các yếu tố được đưa vào mô hình và một phần do thiếu kiến thức của tương tác phức tạp mà ta có thể dựa vào một loạt bản sắc tie tất cả các yếu tố của môi trường / kinh tế mạch tương tác trong một kế toán độc đáo | The effect of climate change and extreme weather events on tourism 179 impacts may amount to per cent of GDP by 2050 the positive impacts to per cent of GDP. These numbers are large compared to other monetized impacts of climate change . Smith et al. 2001 . As can be seen from this review there has been an extensive variety of research carried out on tourism and climate and on tourism and climate change. The majority of these studies look at the role that climate plays in destination choice or in determining demand. Climate data however are based on 30-year averages and so do not account for extreme conditions which may affect short-term decision making. Hence these studies neglect the influence that such extreme weather conditions have on demand whether this is through the choice of destination change to the length of the trip or changing the departure time of the holiday. The following sections of this chapter describe one first attempt to investigate the effects of weather extremes on tourism demand. 3. THE IMPACTS OF CLIMATE EXTREMES ON THE TOURISM SECTOR ACROSS EUROPE THE WISE PROJECT A recent European Commission sponsored study addresses the impacts of extreme weather events on tourism across Europe using time series of tourism and weather data in selected European countries. The tourism impact study is part of a wider project the WISE project Weather Impacts on Natural Social and Economic Systems conducted in 1997-99 in four European countries namely Italy the UK Germany and the Netherlands. The project addresses the evaluation of the overall impact of extreme weather events on the natural social and economic systems in Europe and provides where possible a monetary evaluation of these impacts. Beside tourism the other key sectors studied in the project include agriculture energy consumption forest fires and health. The project was carried out in Italy by the Fondazione Eni Enrico Mattei 4 following a methodology jointly agreed upon by all .
