Cyclones. Monsoons. Floods. Hurricanes. Nature has never been gentle with Bangladesh. Climate change will accelerate its cycles.
"We are nature's laboratory on disasters," said Ainun Nishat, the International Union for Conservation of Nature's representative for Bangladesh. "We don't have volcanoes. But we have every other natural disaster you can think of."
According to the Intergovernmental Panel on Climate Change (IPCC), decades of steadily rising greenhouse gas emissions thousands of miles from Bangladesh are trapping the sun's heat in the atmosphere and creating fundamental changes in the climate. Bangladesh, one of the poorest countries on earth, has almost no control over the cause. Here, the average person emits about 0.3 tons of carbon dioxide each year -- compared to about 20 tons annually for the average American.
But when it comes to seeing the effects of climate change, Bangladesh has a ringside seat. Average global temperatures have risen in the last 25 years, and 11 of the warmest years on record have been occurred in the past 13 years. Glaciers are melting, and across the world, rates of storm surges in some areas and droughts in others are steadily rising.
Already, hydrologists in Bangladesh say, catastrophic floods that once were expected every 20 years are happening almost every four years. According to dozens of published studies, including those from the IPCC, other indicators of what is expected to happen here -- and in some cases already is happening -- include:
- Increased cyclone intensity: The U.N. Development Programme says Bangladesh is the most vulnerable country in the world to cyclones and the sixth most vulnerable to floods. Scientists report 2007 as the worst year on record for intense hurricanes in Bangladesh.
- Erratic rainfall: Scientists expect a 10 percent increase in rainfall during monsoon season by midcentury, while dry seasons could see harsher droughts. Both phenomena are expected to devastate agriculture, particularly rice harvests.
- More floods: About 60 percent of Bangladesh is less than six meters (19.7 feet) above sea level. Each year, about 20 percent of the country floods, but it can be four times that in a particularly bad year. Climate change is expected to create a 39 percent increase in flood-prone areas. Bengalis will see "once in a generation" floods occur every 20 to 40 years. Meanwhile, scientists say once-in-20-year floods already are occurring about every four years. Rising salinity levels as brackish water inundates cropland could mean the loss of 659,000 metric tons of annual rice production.
- Meltwater from the Himalayas provides water to most of Bangladesh. Rapid glacier melt will mean more water flowing down the Ganges and Padma rivers in the monsoon months, causing more devastating floods. In the long term, as the water in the rivers disappears, the result will be more severe droughts.
- Reports vary on how much land could be lost to sea level rise, but some studies warn that if sea levels rise 10.6 inches, 33 million people could lose their land by midcentury. Other factors, like salinity, drainage congestion and erosion, could make the number of displaced people, particularly in coastal areas, climb even higher.