External influences
The tourism factor keeps on rising through the 1980s and 1990s, by reaching 10 million by the 2000s and 14 million by 2014. But the number of arrivals has sharply declined in 2001.
MIGRATION
![Picture](/uploads/5/2/9/6/52969921/202847.jpg?282)
Istanbul has grown very rapidly over the past 100 years, but the population has always very large. They have remained one of the largest cities in the world for the longest time in history. In fact, Istanbul, then Constantinople, had a population between 400,000 and 500,000 in 500 AD, pushing out Rome as the largest ever city in the world at the time.
Environmental Challenges
A natural hazard that Istanbul faces is severe earthquakes. Earthquakes have destroyed many of their buildings and sacred sites.
Marmara Sea is one the most attractive looking marine seas in the world with the shores having beaches, fishing villages, and summer homes. Unfortunately, there has been severe water pollutions that had started a couple of decades ago, when there was a rapid growth in Istanbul. The sea is now critically affected with pollution and tons of wastewater are released from Istanbul's Metropolitan Area. Istanbul has caused air pollution from petrochemicals in urban areas, water pollution from dumping chemical and detergents into the ocean, and oil spill concern from the Bosporus ship traffic increasing. Some national and some international agreements Istanbul has made are with air pollution, Antartic treaty, biodiversity, climate change, desertification, endangered species, hazardous wastes, ozone layer protection, ship pollution, and wetlands. |