Britain claimed a global first Tuesday when it unveiled a much-vaunted climate-change law that would fix targets for cutting carbon-dioxide emissions, set up an expert panel to scrutinize progress, and establish carbon "budgets" to instill discipline in the same way that treasury budgets do.
The bill, still some months away from becoming law, would erect a legal framework for reducing carbon emissions by 26 to 32 percent by 2020 and by 60 percent by 2050. Failure to abide by the law would leave governments exposed to political humiliation and possibly court action in the form of judicial review.
"The draft climate-change bill is the first of its kind in any country," said environment secretary David Miliband. "With climate change, we can't just close our eyes and cross our fingers. We need to step up our action to tackle it."
Environmentalists broadly welcomed the move and said that it would set a positive example of concrete action to tackle climate change to the rest of the world.
But scientists warned that the new-found political vigor may not be enough to keep global temperature rises in check and thus prevent environmental, social, and economic havoc.
"It may be the most significant step from any country across the globe, but from a scientific perspective, it still falls short of what is needed to control climate change," says Prof. Kevin Anderson, a scientist with the Tyndall Centre for Climate Change Research, a leading British global-warming think tank.
Katie Elliott, climate campaigner for Friends of the Earth, says the bill was an exciting moment. "Climate change will now have to be considered in all policy decisions," Ms. Elliott says. "But there are a few questions that still need to be answered, such as if this is commensurate with the scale of the threat. The latest science says that probably it isn't."
The new bill is the tip of an iceberg of initiatives under consideration in a country where climate change is rapidly emerging as a key political issue. Following ominous studies such as the Stern report in October and the UN panel report last month, a recent survey found that 19 percent of Britons feel global warming is now the most important issue facing the country today, compared with 4 percent in 2005.
Politicians appear increasingly aware that green politics may bring in votes. David Cameron, the Conservative leader who cycles to work and is reportedly planning to erect a wind turbine on his home, wants to tax frequent flyers. The Liberal Democrats have long advocated green taxes.
Tony Blair, who is keen to demonstrate tangible effort before he steps down in the summer, on Tuesday called climate change "the biggest long-term threat facing our world." London mayor Ken Livingstone last month announced plans to cut the capital's emissions by 60 percent by 2025.
Britain has also styled itself as an engine for action in the wider European Union, which last week agreed to cut carbon emissions by 20 percent by 2020.
But despite making the right noises about climate change, Britain's results have been underwhelming. It may be on track to meet its Kyoto target of cutting emissions by 12.5 percent of 1990 levels by 2010. But after falling sharply in the early 1990s, carbon emissions have started rising in recent years, leaving environmentalists fuming that hot air will not be enough to save the planet.
The new climate bill would set five-year carbon budgets against which governments can be judged, just as they can for fiscal budgets. A new statutory body, the Committee on Climate Change, is expected to be made up of eight scientific experts who will advise the government on staying within its carbon budget.
Failure to hit the targets would be ill-advised for any government, an official said. "Any government will be under political pressure to stay within the budget so as not to breach a legal duty under the bill," the official said under customary condition of anonymity. "The government would be liable for judicial review," he adds.
Government opponents and environmentalists gave a cautious welcome to the bill, but said that it needed to go further. The law will now pass through several months of consultation and redrafting (it won't become law until early next year) and lobbyists and opposition Conservatives and Liberal Democrats are expected to press for even tougher measures.
The Conservatives are pushing for higher taxes on frequent flyers to address the problem of aviation emissions, which are largely ignored by the climate-change bill because aviation is considered an international affair that requires a multinational deal.
"We have to reflect the cost of carbon emissions in the cost of what we are paying today," says Conservativeshadow environment secretary Peter Ainsworth. "We are paying today's price, which does not reflect the cost to our children and grandchildren."
Some environmentalists, meanwhile, are insisting on deeper emissions cuts, of 80 percent, by 2050. Friends of the Earth wants the government to report back annually to Parliament, rather than every five years, as outlined by the climate-change bill.
A five-year reporting period, says Elliott, "takes you over the term of office for the average government." Some administrations may be tempted, when more pressing needs arise, to ignore climate change, knowing that it would be up to the next government to account for it.
So how will the targets be met? Gordon Brown, expected to take over from Blair as prime minister this summer, said a huge difference could be made by concentrating on domestic households, which produce 25 percent of the nation's emissions. He said that 8 million homes needed proper insulation; low-energy light bulbs are to become a requirement by 2011. Standby lights on appliances should be phased out, he added.
In London, Mayor Livingstone has already targeted motorists through his congestion-charge plan, but his new scheme also focuses on domestic energy use: He is offering subsidies on insulation, advice on helping households reduce their carbon footprints, and support for a high-efficiency form of localized energy generation known as combined heat and power.
But the Tyndall Centre's Professor Anderson warns that "the scale of the problem is not going to be dealt with just by the home sector or just by aviation. All sectors are going to have to see significant reductions."
He is pressing for "personal carbon budgets," a credit card-style system of allocations that people would spend like money.
"It would give people the choice of how to make their reductions," he says. "I could still fly to the US if I lived in an efficient home. Someone else might prefer to use their car but give up their flights."
This may prove to go too far, however. Despite growing concern about climate change, many Britons fret that the country cannot make a difference on its own.