Gordon Brown has been told by cabinet ministers and business advisers that he may have to impose new carbon taxes if he is to meet his ambitious targets to cut UK carbon emissions by as much as 80% by 2050. In his first environment speech as prime minister, Brown warned that climate change science predictions are now so alarming that the current standard, of attempting to cut emissions by 60%, may not be enough.

The country faced "hard choices". He said: "By 2050 we need to be producing between just 155m and 310m tonnes of CO2 annually - less than half as much in an economy that will be two-and-a-half times its present size." Demanding a fourth technological revolution to build a low carbon economy, he said: " Within four decades each pound of GDP needs to produce just one-sixth to one-twelfth of the CO2 equivalent that it does today."

Global greenhouse gas emissions had to peak within the next 10 to 15 years or the world would not meet its goal of preventing temperatures rising by more than 2C. It is the first time the prime minister has put his name to the 80% cut, but the final decision will be made by a new climate change advisory committee.

Brown said he would like to see a total ban on the 13bn single-use plastic bags used in the UK annually, describing them as "the most visible symbol of environmental health". He is to hold discussions with supermarket chains, the British Retail Consortium and other parties with the aim of gaining a voluntary phasing out. Downing Street did not appear keen on the idea of local councils being empowered to impose local bans on such bags.

The scale of the challenge was underlined when ministers also published a report by its commission on environmental markets warning that the government may have to guarantee a minimum carbon price to increase the incentives for business to invest in carbon saving schemes. Brown did praise cap and trade schemes and in a low key way set himself at odds with America by arguing that all developed nations will have to agree binding carbon caps by 2008, the date by which the international community must agree a new framework for carbon reductions.

He insisted: "Only hard caps can create the necessary framework for a global carbon market to flourish." Britain would make its full contribution to an EU target that 20% of energy - not just electricity - will come from renewable sources by 2020. There had been speculation that Britain was trying to undermine the 20% figure. At present only 2% of energy in the UK comes from renewable sources, and Brown admitted that "playing Britain's part will require a huge challenge".

He did not define the precise British contribution to this target, due to be announced in draft form by the EU in January, but said: "Let me make it absolutely clear, we are completely committed to meeting our share. It is clear over the next decade and beyond Britain will need to raise very significantly the proportion of our energy from renewable sources." Most experts believe it will require 40% of electricity to come from renewables.

In an effort to boost the renewables contribution, Brown said he may try to overcome planning objections to onshore wind farms by proposing that local communities reap the economic benefits of turbines, possibly in the form of cheaper energy. Other measures to boost renewables cited by Brown included finding technical solutions to the potential difficulties windfarms pose to air traffic and defence radar, a significant expansion of offshore windfarms beyond 8 gigawatts, a new policy statement balancing wind farms and protecting shipping, and placing tidal lagoons and barrages below one gigawatt capacity within the definition of electricity from renewable energy.

He also proposed a service going house to house in Britain's 50 poorest areas to offer energy efficiency improvements, as well as smart meters in every home within a decade. Brown said: "Building a low carbon economy demands a worldwide commitment on a comparable financial scale to the postwar Marshall plan, requiring billions of pounds of new investment in clean energy. The climate change crisis is the product of many generations, but overcoming it must be the great project of this century. "I know this means facing up to hard choices and taking tough decisions. That it means governing not gimmickry. That is what we will do."

'People don't want to feel helpless'
Rebecca Hosking started the plastic bag revolution in her small Devon town

Six months ago our little trading community of Modbury turned its back on plastic bags, becoming the first town in Europe to do so. Who could have predicted that the actions of a few shopkeepers with a concern for their environment would lead to the PM sitting down with the heads of Britain's supermarkets to discuss the end of the plastic bag as we know it? From the thousands of emails and phone calls I have received, it is crystal clear that people do want to change. Communities don't want to sit by and feel helpless, they just need someone to show them what to do and they will do it.

I feel dreadfully let down by the lack of political will to do anything substantial to protect and repair our planet. However, I can entirely understand where this lack of will comes from. Politicians and parties of all leanings ultimately want to be elected or re-elected to power, so the last thing they want to do is rock the boat with voters. What the grassroots, anti-plastic bag movement has done is given the government permission to act on our behalf. We're saying: "Please rock our boat!"

In Britain today 60 million people are eating up vast amounts of valuable natural resources and churning out worthless and dangerous waste in all forms. I'm so thrilled to hear about the prime minister's planned meeting with the supermarkets and Retail Consortium. However, Mr Brown should be aware that Modbury and countless other communities will be watching him closely. If he emerges from discussions with anything less than concrete plans for the complete and rapid removal of plastic bags from our supermarkets, then he will suffer the embarrassment of us showing him how to do the job properly.

(The Guardian, 20/11/2007)