Washington - The world has woken up to the environmental challenges facing it and is moving towards a "vibrant sustainable economy," the Worldwatch research group said Wednesday in its "State of the World" report.

"There are signs that a vibrant sustainable economy is being created, the product of an extraordinary amd unprecedented wave of innovation that is emerging in sectors like NGOs, consumer groups and governments and spreading to the business and finance worlds," Worldwatch president Chris Flavin told reporters.

The innovations have come as an answer to the growing threat to the global economy posed by environmental problems such as climate change, Flavin told several dozen reporters gathered in Washington, as the US capital basked in spring-like weather in January.

"The big question is, is the innovation enough?" he asked.

Gary Gardner, co-director of the State of the World report, likened the dawn of the global sustainable economy to planting a field.

"We are looking out on the fields in early spring and starting to see buds emerge in the form of innovation," he said.

"Will we have a full crop? Will we have a field in the fall that can be harvested, a field we can call a sustainable economy? It seems clear to us that if these innovations are multiplied and scaled up, the prospects for a sustainable economy are very bright."

In the report, which is in its 25th year, Daniel Esty, a professor in environmental law and policy at Yale University, spoke of "a sea change in business attitudes towards the environment over the last several years."

Global corporations such as General Electric, Toyota and Dow are embracing "clean" technology, he said, not because they are "do-gooders" but because the bottom line is right for them.

Major financial players, including Citigroup and Goldman Sachs, are "investing serious money" in the sustainable economy, said Flavin.

Around 52 billion dollars (35 billion euros) were invested in renewable energy in 2006, up 33 percent from the previous year, the report says.

"We are also seeing a whole variety of private companies for whom environmental improvement is a significant force in terms of their future business planning," Flavin added, citing the example of US retail giant Wal-Mart.

"Walmart is not just focussing on its own environmental footprint ... it is doing something that is much more consequential, going out to its thousands of suppliers all around the world, many of them in China, and putting environmental and social criteria on supplies," he said.

The awakening of the public, business and government to environmental issues has buoyed the prospects for achieving a sustainable economy, said Gardner.

"Years ago, it was environmental groups that were most concerned about environmental issues. Later, governments got on board and now we see key players in business involved," he said.

"When you see all three of those major sectors of society working on those issues and increasingly working together, there is real hope of turning our economies into sustainable ones."

But the challenge has to be taken up fully and quickly if it is "to lead to new innovative ways to organize economic activity and avoid a breakdown of the global economic system and the unravelling of political institutions," Flavin said.

"This is the single largest challenge facing the world today," he said.