By Richard Black
Environment Correspondent, BBC News website
Prudent politician that he is, Gordon Brown was unlikely to adopt the mantle of Swampy for his 10th Budget, despite the heavy trailing of its green tinge.
So there are changes to vehicle excise duty designed to promote cars with lower greenhouse gas emissions; but they are modest, and fuel price rises are postponed.
The budget includes small rises in duty for high-emitting vehicles
There is new money for micro-generation and stimulation for "clean coal" technologies; but not too much.
There is modest reform of the climate change levy, rather than the abolition or conversion to a carbon tax urged by the Conservatives and Liberal Democrats respectively.
There was a modest amount of spin, too. Labour policies have brought Britain to a position where it can meet its Kyoto Protocol target for reducing greenhouse gas emissions, said Mr Brown, ignoring the much bigger impact of the "dash for gas" under the Conservatives before 1997.
Running through most of the environmental areas was the need to safeguard energy supplies and engage with industry; familiar themes from this government in recent times.
Nevertheless, the Budget has been well received by environmental groups and think-tanks.
In the comments of Greenpeace UK's executive director Stephen Tindale, though, one can detect more than a hint of desperation that Mr Brown should prove a greener Prime Minister than Tony Blair if and when he moves into 10 Downing Street.
"This Budget may be the first sign that we're about to get a Prime Minister who acts on climate change instead of just talking about it," he said.
"Many of these measures will make a difference if properly implemented."
But frustration remains that there is not a greater difference between the rates of vehicle excise duty to be paid by high- and low-emitting motorists, which will see the cleanest cars subject to zero duty and the most polluting paying £210 annually, up from £175 now.
"The creation of a new top rate of road tax is the right way to go," said Mr Tindale, "but the chancellor must know that £210 is far too little money to stop anyone buying a 'gas guzzler'.
"We will continue to press him to increase the top rate to £1,800."
Another transport-related measure much touted in some quarters was a hike in air passenger duty.
Currently, emissions from air travel are rising faster than those from any other sector of the economy.
But citing recent price rises and price instability in jet fuel, Mr Brown decided to leave duty unchanged.
In recent months, the government has been heavily criticised by the renewable power industry over first delaying its new support fund and then putting up less money than it has supplied in previous years.
There is a new fund to promote micro-generation
But Matthew Spencer, chief executive of Regen SW, the renewable energy agency in the south-west of England, had some positive words for the Chancellor's announcement of a new £50m fund for micro-generation.
"It's a significant boost if that money is well spent," he told the BBC News website.
"We would hope it will be spent on householders and small businesses in existing buildings, and regulation rather than grant funding used for new buildings.
"There should be no new building of homes or offices that don't have a significant proportion of renewable generation built into the fabric of buildings; it's a voluntary measure that not many councils have taken up, and it should be made mandatory."
Even with this new money, Britain remains substantially behind some of its European neighbours in support for small-scale renewables, and uptake of these technologies is minuscule, amounting to less than 1% of electricity generation.
The levy breaks
The climate change levy is one of the concrete measures Labour brought in to try to reduce carbon emissions from British industry.
Conservative leader David Cameron maintains it does not work because it targets energy rather than emissions, and wants it abolished; Liberal Democrat policy is to change it into a carbon tax similar to the one which Norway has had in place since 1991.
Gordon Brown has delivered a modestly green budget
Mr Brown was at his most abrupt in dismissing either option. Instead, he is index-linking the sums businesses must pay.
Michael Grubb, a professor at Imperial College London and policy director of the Carbon Trust, believes it will make little difference to Britain's emissions either way.
"This would imply that one option has been ruled out - that of considerably increasing the levy, which is not surprising in times of high energy prices," he said.
"I think the best that could be said is it will help stop us going backwards."
It is not clear that any of Mr Brown's measures will make a serious dent in Britain's contribution to climatic change.
But in the context of other government business, this was probably one of the worst times to try to deliver a Budget which contained such an ambition.
The government's review of its climate change policies is published next week, while further ahead this year is a similar review of energy policies.
If they are to be meaningful, these both ought to bring recommendations for policies on taxation and spending.
All of which gives Mr Brown until next March to decide whether and how to implement them - assuming he is still in No 11 at that stage, and not next door.