"If we can get a good climate bill [in the US], then great. If we don't get one, it is not the end of the world, because we will still be closing coal-fired power plants and we are still going to be building wind farms,"Brown said, speaking ahead of the Brussels launch of his new book, Plan B 4.0.
According to Brown, who founded Washington-based think-tank the Worldwatch Institute and heads now the Earth Policy Institute, international negotiations to deliver a global deal to succeed the Kyoto Protocol are "obsolete", as the key driver for lowering emissions will instead be genuine competition in developing new energy technology.
The climate guru did not shy away from spelling out an endless list of examples. In Europe, he described Desertec, which aims to power Europe with solar energy from the African desert, as a visionary project that can fast-track the EU's transition to clean energy.
Likewise, the United States and China are also aggressively embarking on a more sustainable energy path, rapidly developing their capacities in wind and solar energy.
If they move in the right direction then the world is going to follow, he told EurActiv.
"I sense that we are moving to the tipping point. If you just look at things that have happened in the last couple of years - the anti-coal movement, the European Desertec, the Chinese wind programme - they have happened in a very short-time and each is a major development in its own right. None of the three had really anything to do with climate legislation," stressed the American climate expert.
Brown noted that if the Chinese have not supported an international climate deal, it is because a "meaningful agreement would drive countries everywhere to invest in new technologies and new energy sources".
Resource depletion, pollution and the drive for energy security will push countries to leave fossil fuels behind, Brown said, explaining that it is only a matter of time before governments realise what businesses and grassroots movements have already grasped: that it is time to move towards the new green energy economy.
Several trends in the US are showing vital signs of change, said Brown. He cites as an example the shrinking US automobile fleet, which has decreased by four million vehicles in the past year, down from 14 to 10 million new cars sold.
New car sales will continue to fall in future, predicts Brown, explaining 80% of American live in cities and young people in the US are changing their attitudes towards cars.
"When I was a teenager in Southern New Jersey, for everyone in my class getting a driver's licence and a car was a right of passage. Socialising depended on the car," he explained. "But today young people socialise over the Internet and mobile phones, and cars are [no longer] such a big part of teenage socialisation."
Powerful anti-coal grassroots movement
Another factor that is pushing the US to embark on a low-carbon future is the powerful grassroots movement opposing coal-fired power plants. "This has made it impossible to get a licence to build new coal-fired power plants, and we have a de facto moratorium on new plants," Brown said.
"Now that the campaign to prevent the building of new coal-fired plants has succeeded, groups are moving to stage two, which is to close existing coal-fired power plants," he said, noting that at least 30 coal-fired plants are scheduled to close.
According to the Worldwatch Institute, coal usage has dropped 11% in the last two years, partly as a result of the recession, but also due to the fact that renewable energy sources have increased: over the same two-year period, 191 new wind farms began to operate in the US.
Nuclear energy: A lot of smoke with no fire …
Dismissing reports that there is a nuclear revival in the United States, the climate guru argued that the economics of nuclear power has become almost impossible due to the high cost of building new-generation reactors.
Since Chernobyl the industry has largely died, he said. "Now there are very few young people going into nuclear physics and nuclear engineering. Many of the suppliers of various parts have largely disappeared. So it has become very difficult and costly to build new nuclear power plants," he explained, citing as an example the Olkiluoto facility in Finland, which will not be completed before 2012, three years behind schedule.
"There is a lot of noise. But noise is not the same as building new nuclear power plants," he said.
Food bubbles about to burst
The real crisis about to happen lies in the world's aquifers. "There are a number of food bubbles in the world that are the result of over-pumping. Half of the world's population lives in countries where aquifers are being depleted," Brown said, noting that some countries like Saudi Arabia will no longer be self-sufficient in wheat production.
He predicts that the world economy will hit peak water and peak oil at about the same time. "Both affect food security and that is a matter of concern," he said, calling for a worldwide effort to raise water productivity in the same way that Western countries adopted land productivity strategies in the 1950s.