DOMINO EFFECT - FLOODING OF MANGROVES TRIGGER DISAPPEARANCE OF TIGERS

While tigers are a highly adaptable species, thriving in the snows of Russia to the tropical forests of Indonesia, the Sundarbans ecosystem has become an isolated refuge, boxed in by humans and the sea. Although there is considerable uncertainty regarding the degree of future habitat loss due to [sea level rise], it is still imperative to act now to mitigate the potential habitat loss. If we fail to act globally, regionally, and locally to conserve the Sundarbans, our collective inaction may result in the tiger joining the polar bear as early victims of climate-change induced habitat loss.

according to a new paper in the journal Climatic Change, there is another, unexpected example of charismatic megafauna whose future may be in question as a result of global warming: The Bengal tiger - or at least, one isolated population thereof.

However, sea level in the Sundarbans rose by between 4 and 7.8 mm a year from 1977 to 1998 - the level increasing from east to west - as a result of a combination of global sea level rise, sedimentation,  withdrawal of water, oil, and gas, and subsidence. The Intergovernmental Panel on Climate Change (IPCC) estimates a similar, global rate of increase in sea level, of around 4 cm a decade, suggesting that somewhere around the year 2070, sea level in the Sundarbans could be 28 cm higher than it was in 2000.

It's no secret that Bengal tiger numbers have declined; the species now occupies only about seven percent of its historic range and is believed to total fewer than 4,000 in the wild. In Bangladesh, tigers are restricted to the Sundarbans, one of the largest mangrove forests in the world; a 2009 study estimated the population numbered about 500 animals.

The paper's authors used a detailed analysis of the topography of the Sundarbans to calculate the likely impact of increasing levels of inundation. By the time it reached 28 cm, they calculated, available habitat suitable for tigers would have declined by 96 percent, and the population would likely be substantially reduced, to perhaps as few as 20 breeding adults. At that size, the population would almost certainly no longer be viable.