A United Nations report said nearly one-quarter of all species of mammal are threatened with extinction over the next 30 years. The findings are contained in the U.N. Environment Program's latest study on global environmental trends.
The U.N. report said environmental pressures are mounting on animal and plant life in many parts of the developing world.
The study, to be released in London Wednesday, finds that 24 percent of mammals and 12 percent of birds are threatened with extinction over the next 30 years. More than 5,600 plant species are also threatened.
The report said biodiversity is being lost due to human activities, including the introduction of alien species from one part of the planet to another and human encroachment on animal habitats.
The U.N. report also said declining environmental quality is taking a heavy toll on the health and wealth of people in developing countries. India, for example, is losing more than $10 billion a year because of environmental degradation.
The study said a burgeoning population has put great strain on groundwater supplies. About one-half of all the world's rivers are seriously depleted and polluted. By the mid-1990s, about 40 percent of the world's people were suffering serious water shortages.
The U.N. said air pollution levels also continue to rise. The atmosphere contains 30 percent more carbon dioxide than it did 250 years ago.
Not all the news is bad in the U.N. report. It said the proportion of hungry people in the world is on the verge of falling. And it said there have been notable improvements in the past 30 years in air and water quality in developed regions such as North America and Europe.