The Italian government's $2.6 billion plan to save Venice has pitted two environmental concerns against each other: containment of rising sea levels versus protection of a lagoon ecosystem. As the oceans ascend and the land subsides, Venice faces serious flooding. The government is responding by constructing 79 mobile underwater barriers that would act as emergency floodgates. Proponents contend that global warming could increase the water level by as much as 20 inches during the next century, making the barriers a necessity. "Venice will not survive otherwise. The socioeconomic impact of floods even now is very large," says MIT hydrologist Rafael Bras.
But the canals of Venice are just one part of a natural lagoon that is constantly cleansed by irrigation from the Adriatic Sea. Many environmentalists have protested the Italian proposal, worrying that it will lead to serious pollution of the city and surrounding waters. Moreover, Trevor Davies and his colleagues at the University of East Anglia in England claim there is no need for drastic action. Their research indicates that global warming has actually quelled the most serious flooding during the past 40 years because it has weakened local storms, which tend to cause the most damaging floods. Although Davies says that "some form of protection is needed," he argues that mother nature may already be solving Venice's most serious problems. For now the flood-control project is moving ahead.