Ridding the Ganges of thousands of tons of plastic trash is a complex puzzle. India is starting to put the pieces together. In the past decade, immediately as the world has awakened to the growing accumulation of plastic debris in our oceans, the efforts to solve the mounting crisis have been numerous, imaginative  and insufficient. In about twenty years, the amount of plastic flowing annually into the sea is forecast nearly to triple to thirty two million tons a year. That means that by the time a baby born this year graduates from high school, there will be, on average, a hundred pounds of plastic trash for every single yard of coastline around the globe. The message from scientists is, it is not too late to fix it. But there is no time for small steps. Most of the research about plastic waste has focused on plastic already in the oceans and its potential for harm  it poses a lethal threat to a wide range of wildlife, from plankton on up to fish, turtles, and whales. Less is known about how the waste gets to the ocean. However, it is clear that rivers, especially rivers in Asia, are the major arteries. Three years ago, the National Geographic Society sponsored a huge research expedition to one of those rivers: the Ganges, which flows across northern India and Bangladesh, through one of the largest and most heavily populated river basins in the world. A team of forty scientists, engineers, and support staff from India, Bangladesh, the United States, and the United Kingdom travelled the full length of the river twice, before and after the monsoon rains that dramatically swell it. Sampling the river and the land and air around it, interviewing more than a thousand residents, the team finally sought to find out where, why, and what kind of plastic was getting into the Ganges  and from there into the Indian Ocean. The problem cannot be solved if you do not know what it is, says Jenna Jambeck, an environmental engineering professor who was one of the leaders of the expedition. It was her groundbreaking research, including her calculation that an average of more than eight million tons of plastic end up in the oceans every year, that soon captured the worldwide attention and helped transform marine plastics into a top environmental concern. Like most experts, Jambeck believes the solution lies not in cleaning up the oceans but in reducing and containing plastic waste on land, where most of it actually originates. Like climate change, plastic waste is a side effect of our hydrocarbon habit and its impact is both local and global. 
