The U.S. economist who predicted in 1972 that the world was facing environmental disaster has ridiculed the Copenhagen climate change summit and says only a series of global crises will incite the world to take concrete action.

“Copenhagen? I don’t take it seriously. The whole thing is a huge ploy,” said Dennis Meadows, co-author of The Limits to Growth, a blockbuster report that argued the world faced catastrophe if population growth and resource use wasn’t reconciled with environmental sustainability.

He said only a tiny proportion of the world’s population is even aware world leaders, including U.S. President Barack Obama and Prime Minister Stephen Harper, are gathering in Denmark’s capital city this month to seek an accord to limit climate-changing greenhouse gas emissions.

“This conference is essentially about doing as little as possible, not as much as possible,” Mr. Meadows, 67, told the German newsmagazine Der Spiegel this week. “I think 98% of humans haven’t even heard the word Copenhagen.”

He said it’s critical the public do more to reduce their carbon footprint and ease energy dependence, but he said it’s too late to do much more than slow climate change.

“It might have been possible to prevent serious climate change in the 1970s and 1980s, but it isn’t any more,” said Mr. Meadows, who earlier this year was awarded Japan’s prestigious $500,000 prize from the country’s Science and Technology Foundation.

“We are on a roller coaster at the top of the hill, and all we can do is hold on tight.”

The world will only take dramatic action when faced with “a series of crises,” he predicted.

“It is only when there are abrupt climate changes, unpleasant ones, that the willingness will come about to really do something.”

He said the world’s population of 6.8 billion people is excessive, and only possible because such a large proportion live in poverty, unable to own the pollution-causing cars and homes with modern appliances.

“If you think it is acceptable to have a small elite that enjoys a decent lifestyle and a large majority that is excluded from that, then the Earth can probably sustain five to six billion people,” he said.

“If you want everyone to have the full potential of mobility, adequate food and self-development, then it is one or two billion.”

Mr. Meadows was among a group of scientists at the Massachusetts Institute of Technology who co-authored the 1972 study on behalf of the Club of Rome, a think-tank established four years earlier to advise the world on environmental sustainability.

The report, issued at a time when the world’s population was just under four billion, used computer simulation models to assess the impact of population growth on food and industrial production, pollution, and consumption of non-renewable natural resources.

A majority of the scenarios predicted disaster if growth and consumption trends weren’t changed significantly.

The report was explosive and controversial, selling more than 12 million copies in 30 languages.

The Club of Rome credits The Limits To Growth for the creation of ministries of the environment in most of the world’s governments starting in the 1970s.

Though the report was criticized at the time, the quality of the projections turned out to be “amazingly good, unfortunately,” Mr. Meadows said.

“We are in the midst of an environmental crisis, which we predicted then. The difference is that we have lost 40 years during which humanity should have acted.”