The world's city dwellers are fast producing more and more trash in a "looming crisis" that will pose huge financial and environmental burdens, the World Bank is warning.

Urban specialists said the growing pile of trash from urban dwellers is as daunting as global warming and the costs will be especially high in poor countries, mainly in Africa.

In a report on "a relatively silent problem that is growing daily," released on Wednesday, the World Bank estimated city dwellers will generate a waste pile of 2.2 billion tonnes a year by 2025, up 70 percent from today's level of 1.3 billion tonnes.

In the meantime, the cost of solid waste management is projected to soar to $375 billion a year, from the current $205 billion.

Billing the report, "What a Waste: A Global Review of Solid Waste Management" as the first worldwide comprehensive look at trash, the World Bank warned the data points to crisis ahead, as living standards rise and urban populations soar.

"The challenges surrounding municipal solid waste are going to be enormous, on a scale of, if not greater than, the challenges we are currently experiencing with climate change," said Dan Hoornweg, a senior urban specialist at the development lender and co-author of the report.

"This report should be seen as a giant wake-up call to policy makers everywhere," he said.

China, which eclipsed the United States as the world's largest waste maker in 2004, generates 70 percent of the trash in the East Asia-Pacific region.

China, other parts of East Asia, and parts of Eastern Europe and the Middle East have the fastest-growing production of municipal solid waste.

The World Bank economists called for better waste management and recycling to combat greenhouse gas emissions, saying the old concept of "throwing away" trash no longer works.

"In solid waste management there is no 'away,'" the authors said.

"When 'throwing away' waste, system complexities and the integrated nature of materials and pollution are quickly apparent."

The report's authors recommended a waste management plan that includes input from all of a city's stakeholders, including citizen groups and the poor and disadvantaged.

The report also pointed to recycling and other measures to reduce greenhouse gas emissions that come from inefficient solid waste management practices.

"Improving solid waste management, especially in the rapidly growing cities of low-income countries, is becoming a more and more urgent issue," said Rachel Kyte, vice president, Sustainable Development at the World Bank.

"The findings of this report are sobering," she said.

"But they also offer hope that once the extent of this issue is recognized, local and national leaders, as well as the international community, will mobilize to put in place programs to reduce, reuse, recycle, or recover as much waste as possible before burning it -- and recovering the energy -- or otherwise disposing of it."