A fragile environment is one which is easy to disrupt, and once disrupted, difficult to restore. An example of this kind of environment is the Sundarbans; the largest single block of mangrove swamp in the world, covering 10,000 km² from the coasts of West Bengal to Bangladesh. The mangrove swamps are sensitive to a number of factors, including temperature, salinity and sea level, where small changes may be able to cause huge impacts on the overall health and effectiveness of the swamps to protect the coastline and the 300,000 livelihoods that depend on it.
The mangrove swamps can act as shock absorbers, protecting communities from cyclones and storm surges that frequent around India and Bangladesh, such as Cyclone Sidr in 2007, which killed 3,000 people. The mangroves are the first line of defence against the devastating cyclones, able to absorb 30-40% of the total cyclone force, being a vital asset to the poorest in Bangladesh, a country with GDP of only USD$1,900 per capita. Apart from protection, they also play a vital role in the economy, where the diverse biodiversity is able to attract tourists from all over the world. However, the Sundarbans is under threat. The rise of sea level from climate change would lead to 75% of area submerged from a rise of 45cm, while the entire Sundarbans would be inundated and submerged with a rise of 1m, and at current rates of 3mm a year, it would mean the disappearance of 96% of the Sundarbans within half a century. Increasing sea levels also mean that there will be increased salinity of the land and water, with lean river flows that fail to push out the sea water surges inland, trees such as the Sundari tree will continue to suffer from top-dying, where excess saline waters creep into the underground water tables and cause the tree to rot from the top down. Human threats such as poachers and fishing