In many of the nations taking part in Earth Hour this year, the lights already go out on Saturday nights – not to raise environmental awareness but as part of regular power cuts.

Having dinner by candlelight is a matter of routine rather than romance, and about 1.5 billion people have no access to electricity, the International Energy Agency says.

Yet developing countries, and above all China and the emerging economies of Asia, have now emerged at the forefront of Earth Hour, thanks to the number of people enthusiastically taking part and the way they have used the annual event as a platform for environmental change.

"Here in Australia, the environmental message is very polarised by politics," says Dermot O'Gorman, the chief executive of WWF Australia, which organises the event.

"In China, for example, there is no political ideology attached to tackling environmental problems. Also, the problems there are staring them in the face."

People in at least 135 countries and independent states will turn off their lights for an hour on March 31, to mark the event that started in Sydney five years ago. Based on data from previous years, most will have incomes less than half that of the average Australian, and a carbon footprint about six times smaller.

WWF Australia, which organises the global event through its network of environmental campaigners, is fighting the perception that dragging people out of poverty is incompatible with cutting greenhouse gas emissions and protecting the natural world.

While the event attracts some cynicism in Australia, where corporations compete to be seen as the most environmentally friendly, most Earth Hour events overseas have arisen from the grassroots and reached business and governments only later.

In Swaziland, Earth Hour was started by the actions of one teenage boy, Nathi Mzilenzi, who arranged a symbolic lights-out event in his town of Shimunye in 2010. In Iraq and Bhutan, local groups have encouraged their governments to sign up to Earth Hour this year.

The more obvious physical evidence of climate change, pollution and destruction of the environment in the developing world may mean people there have a more visceral reaction to it, psychologists suggest. The Psychology of Global Warming, a 2010 paper by Sydney researchers, concluded it was natural for people insulated from environmental problems to be sceptical of them. They showed that people normally try to refer to real-life examples to draw conclusions and may be heavily influenced by recent media coverage.

One of the authors, Dr Ben Newell, says: "For example, if you read or hear opinions from climate-change sceptics about 50 per cent of the time then this could lead to a bias in the perception of the balance of evidence in your mind – that is, that the science is only about 50 per cent certain."

People are also heavily influenced by "framing issues" – how information is presented to them – the global warming study said.

To try to frame Earth Hour as a big, universal event, the organisers have deployed the power of celebrity where possible, especially in India, where the star cricketer Sachin Tendulkar was asked to front the campaign.

“It is heartening to see how a single action of switching off lights for Earth Hour can bring the world together to pledge action towards a better environment," Tendulkar said in a statement. "I am happy to be a part of this movement and encourage others to participate as well."

In China, the event has been linked to huge environmental programs, with municipal governments competing to be seen to be green in the eyes of their citizens. In Liaoning, authorities paid for the planting of about 3.4 billion trees; in Chengdu, 50,000 bicycles were bought by the government for cheap public rental from 1000 bike stations; and in Yangling the event was a catalyst for cleaning and improving the management of the Wei River system.

O'Gorman, previously the director of WWF China, was instrumental in the negotiations to bring Earth Hour to China for the first time in 2009.

"We were very lucky in a sense in that this was just before the Copenhagen conference and in the run-up to the Olympics, so it was seen there as very important for China to take part in Earth Hour," he says.

"People tend to look at some of these countries from Australia and think of them as being developing countries with low incomes. In fact there is enormous wealth held by a small group of people and what is also emerging is the largest middle class in the world in India and China. Everyone is concerned about the environment. In particular, you see in the middle class a growing environmental awareness."

twitter Follow Environment on Twitter