After weeks of spin leading us to believe that we were going to see the most environmentally conscious budget ever, Gordon Brown’s government finally bottled it and gave us more of the same old cautious and uninspired economic outlook.

Instead of seizing the opportunity to reshape our economy to deal with the serious threat of climate change, Alistair Darling used his much-awaited first Budget to set out a weak and flimsy agenda which brought new definition to the word ‘greenwash.'

It tells you all you need to know about the government’s attitude to the environment that Darling chose the section on climate change to reaffirm his commitment to expanding both Heathrow and Stansted airports. He claims he wants tougher carbon reduction targets, but if air travel expands in the way he wants, the only way to meet the cuts we need would be to sacrifice every other part of our economy.

Under pressure from roads lobbyists, Darling backed down on the already timid 2p rise in fuel duty, putting it back until autumn apparently due to high oil prices. If he really thinks oil will be cheap by October, his basic understanding of economics is suspect at best. Fossil fuel costs will remain high as long as demand remains high and conventional oil resources dwindle, and cowardly decisions like this will only make the problem worse, with solutions ever further from our grasp.

The £20 increase in child benefit is of course welcome, but it falls well short of what is required to meet the government’s laudable targets for cutting child poverty. The billions it would take to halve child poverty by 2010 are instead being spent on our illegal and immoral military pursuits – occupying Iraq and Afghanistan is set to cost £3.3bn in 2008 alone.

On plastic bags, the government has at least shown that it is listening to the public by acknowledging that action needs to be taken - and yet, even on this minor issue, the Budget has ultimately failed to deliver. Darling could have seized an ideal opportunity to introduce a green tax, or to look at the feasibility of phasing the bags out all together. Instead, he weakened the green line by wagging a feeble finger at retailers warning he would legislate next year to impose a charge on disposable plastic bags if they failed to take action to reduce them. So, rather than having the courage to enforce a government measure, like a mandatory tax, we now have to wait for individual retailers to take action.

To make matters worse, while such minor initiatives do represent a step in the right direction, they are a drop in the ocean when you consider the scale of the climate change challenge. By focusing the public's awareness on plastic bags, the government distracts attention away from its plans for a massive expansion of aviation and a new generation of coal-fired power stations - plans which amount to nothing less than climate vandalism.

Green taxation could be an effective method of charging more for carbon-intensive activities and channeling the money into new efficiency measures and the renewables industry. But such green taxes must have the support of the people. Darling has run scared, sticking close to the old economic mantra that it is economically and politically unsound to make explicit links between money raised by a particular tax and spending the revenue on the very issue that the tax was designed to address.

So, above all, this Budget was a criminally wasted opportunity to set the country on the path towards a more sustainable future. Where was the windfall tax on the huge profits of the large energy companies, for example, who look set to receive £9bn over the next four years in free allocation of emissions trading permits?

What we need is a real commitment to spending on the things that matter, we need to insist that employers pay a real living wage, and we need to end the assault course of benefit traps and welfare blackmail that the government has set up on the border between benefits and work. Most importantly, we need to see the Chancellor taking a lead on climate change and showing the British people that the government is serious about rising to the challenges ahead.