Now the green vote matters: Climate Change on the Political Agenda
As a party political issue, the environment has been a slow grower. The fact that two prime ministers-in-waiting are currently raising the political heat over global warming shows how far the topic has travelled up the agenda.
Indeed, the battle for the green vote between the new adversaries intensifies today, with David Cameron revealing he would replace the controversial climate-change levy, the government's prized pollution tax on business, with a new "carbon levy".
In a speech in Oslo following a trip to see Arctic glaciers off Norway, the Tory leader will urge people to embrace change in the way they lead their lives as well as technological innovation to create a greener world.
His words follow a keynote address from Gordon Brown at the UN in New York, in which he defended the climate-change levy, saying it was "central" to the government's approach to cutting CO2 emissions. Over the next five years, it would lower such pollution by six million tonnes, one third of Britain's total carbon reductions by 2010.
"What the levy shows is that by targeting the marginal use of energy, we can provide real market incentives to energy efficiency," he said.
The chancellor also argued that developed countries' economic and environmental objectives increasingly reinforced each other, saying: "We must match growth and justice with environmental care."
Whether the respective words of Mr Cameron and Mr Brown are political hot air or genuine attempts to tackle one of the greatest challenges will ultimately be decided at the ballot box.
But the green agenda has certainly come a long way from relative obscurity.
Back in 1986, the Green party won its first council seat in Stroud. Now it has 70 across England and is hoping to top 100 on May 4. It has seven MSPs, two MEPs and two London assembly members. In Scotland, the Greens are hoping the heavy emphasis on matters environmental will boost their chances at next year's Holyrood elections and see them win their first local-government seats north of the border.
Not surprisingly, George Baxter, their spokesman, views the Tories' new green creed as a cynical attempt to grab votes. Lumping Labour, the LibDems and Tories together as "the grey parties" for their lack of genuine commitment to the environment, he dismissed Mr Cameron's newly acquired emerald sheen as mere glossy packaging. "It's just rhetoric."
Rhetoric or not, the green agenda falls conveniently into the middle of Mr Cameron's brand of modern Conservatism – compassion and quality of life, the elements that will dominate Tory policy in the years ahead.
The Tory leader's declaration of wanting to lead a "new green revolution in Britain" has raised questions about whether he is sincere or is adopting a green veneer to bag votes; his party's slogan for the May 4 elections is "vote blue, go green".
A poll earlier this year confirmed voters were increasingly prepared to make sacrifices to sustain the environment. Around 63% of respondents approved of a green tax to discourage behaviour harmful to the environment.
For the most part, Mr Cameron has avoided detailed policies, saying they are still under review. But he has argued that without economic "green growth", the measures to tackle climate change cannot be afforded.
Guy Thompson, director of the Green Alliance, a leading environmental think tank, described the Tory leader's new-found focus as "useful" in raising the political stakes but insisted the jury was out on new green Conservatism: "We will be looking for solid policy commitments and hope Cameron is not using his party's policy review to buy 18 months of policy-free space."
He said the "acid test" of the Tories' new commitment to the environment would be their position on the government's energy review – and specifically on nuclear power.
Mr Thompson said it would certainly put "green water" between the Conservatives and Labour if Mr Cameron decided his party would be opposed to a new generation of nuclear power stations.
As for Labour, he added Mr Brown had had a "blind spot" on the environment, which was "something he is having to turn around".
Yesterday, as Mr Cameron gazed at melting icebergs off Norway, the chancellor was in New York telling world leaders climate change needed a global solution. Over the next 48 hours, he will explain how Britain will invest in a new institute for research into alternative sources of energy and will call for an £11bn facility to diversify developing countries' energy supply.
Just to underline the party-political dash for the green vote, a source close to Mr Brown highlighted that while the Tory would-be PM was seeking photo opportunities next to icebergs, the chancellor was telling it like it is to a tough American audience. "Which is the more statesmanlike action?" he asked.
Since it came to power, New Labour has increasingly raised green issues but its actions have failed to satisfy campaigners. While Tony Blair's government will meet the 12.5% Kyoto target on reducing emissions by 2010, it is set to miss its own of 20%, achieving a cut of 15-18%.
In 2004, Professor Sir David King, the government's chief scientist, said the threat to the planet of global warming was worse than from terrorism. Last week, he warned the Earth's temperature was likely to rise by at least 3C, putting 400 million people at risk of hunger and leaving up to three billion without adequate water supplies.
But while the environment will be the stuff of domestic politics in elections to come, expert and non-expert alike realise only by concerted worldwide action can the planet's climate be saved.
America, the world's largest polluter, is relying heavily on new technology to produce the solution; neither George W Bush nor the US Congress is willing to jeopardise Americans' standard of living.
As it develops at breakneck speed, the new kid on the economic block, China, is setting tough targets on limiting energy consumption and reducing pollution. But it has missed them year on year.
Every day, 1000 new cars are estimated to hit the streets of Beijing. There are currently three million private cars in the capital. By 2020, estimates suggest China will have 140 million – more than the US.