"A window of opportunity to act is now open," the organization said in its Environmental Outlook to 2030. "We need forward-looking policies today to avoid high costs of inaction or delayed action over the longer term."
The outlook, part of a series of reports compiled every five years, was being presented by the organization's secretary-general, Angel Gurria, in the Norwegian capital on Wednesday. The latest report concentrates on "red light issues" in such areas as climate change, water shortages, energy needs, biodiversity loss, transportation, agriculture and fisheries.
"Without more ambitious policies, increasing pressures on the environment could cause irreversible damage within the next few decades," said the summary released in advance. "The cost of inaction is high, while ambitious actions to protect the environment are affordable and can go hand-in-hand with economic growth."
Although the organization is made up of 30 European nations, the report stressed the need for a global response to environmental challenges.
It said that by 2030, the world's population, currently about 6.5 billion people, is expected to hit 8.2 billion, and the global economy could double in size, largely due to growth in countries like Brazil, Russia, China and India. Unchecked, growth in energy consumption in those countries could be 72 percent by 2030, compared to 29 percent for all 30 OECD countries.
That would lead to a 38 percent increase in climate-damaging carbon dioxide emissions by 2050, even if the Organization for Economic Cooperation and Development reduced its own emissions by 43 percent through a carbon tax of US$25 per ton starting this year. However, if Brazil, Russia, China and India take the same step in 2020, and are followed by the rest of the world in 2030, emissions could be held at 2000 levels.
Globalization can help solve the world's environmental problems or make them worse, depending on what steps are taken now to shape the world economy, the report said.
"While globalization has a range of potential impacts both good and bad on the environment, the state of the environment and natural resources also affects economic development and globalization," the organization said.
The report included a model of the impact on the environment if no steps were taken, compared to the result if the report's policy recommendations were adopted worldwide.
With no measures, the world gross domestic product is expected to grow 99 percent between 2005 and 2030, with severe environmental consequences, it said. With measures, growth would be nearly the same, 97 percent, but with a much healthier environment.
"A policy package to address some of these key environmental challenges could cost as little as 0.03 percentage points in average GDP growth globally to 2030," it said.
The report said governments must create such policies as "green taxes" to encourage sound technologies and practices, and that the rich world must help poor countries develop without spewing pollution by providing technology and expertise.
It also said ecological advances bring multiple benefits. For example, cutting motor vehicles' greenhouse gas emissions would improve air quality in cities; better insulated homes cut power bills for consumers while reducing power plant emissions; reducing agricultural run-off of nitrogen fertilizers could cut emissions of climate damaging gas nitrous oxide and provide cleaner water supplies.