The Yangtze faces a future of extreme weather events such as floods
The Yangtze river basin is being increasingly affected by extreme weather and its ecosystems are under threat, environmentalists say.
In a new report, WWF-China says the temperature in the basin area of China's longest river has risen steadily over the past two decades.
This has led to an increase in flooding, heat waves and drought.
Further temperature rises will have a disastrous effect on biodiversity in and along the river, the report says.
The WWF - formerly known as the World Wildlife Fund - predicts that in the next 50 years temperatures will go up by between 1.5C and 2C.
The group's report is the largest assessment yet of the impact of global warming on the Yangtze River Basin, where about 400 million people live.
Data was collected from 147 monitoring stations.
The report's lead researcher, Xu Ming, said the forthcoming Copenhagen negotiations on climate change would have an obvious and direct influence on the Yangtze.
"Controlling the future emissions of greenhouse gases will benefit the Yangtze river basin, at the very least from the perspective of drought and water resources," he said.
The report says the predicted weather events and temperature rises will lead to declines in crop production, and rising sea levels will make coastal cities such as Shanghai vulnerable.
Some of the problems could be averted by strengthening river reinforcements, and switching to hardier crops, its authors suggest.