The world faces an economic collapse on the level of a World War or a depression if climate change is not averted, according to a report by economist Sir Nicholas Stern.
Power firms have to cut emissions by 60-70%, the report says
Here, the BBC News website's business editor Tim Weber and environment correspondent Richard Black answer a selection of readers' questions.
Surely things like energy-saving light bulbs and forcing people to ride bicycles is a way to reduce emissions. Why does this government think that the only way to solve a problem is raising tax?
Richard Scott, Iver, UK
Richard Black: The argument used by some politicians and economists is that regulation is less efficient than setting up market mechanisms. This is why we have the European Emissions Trading Scheme rather than, for example, legislation banning short-haul flights or mandatory standards for vehicle fuel efficiency.
Stern is quite clear on the need for regulation but sees it primarily as setting the framework for market mechanisms. Another view of the reluctance to regulate can be found here:
Are we going to be stuck with these taxes for life? When this country's emissions targets are met does that mean the taxes will go away?
Gas bubbles trapped in ice store valuable climatic information
Robert, West London
Tim Weber: We don't know yet what the new green tax regime will look like. As you point out correctly, a resounding success on the green front would mean that the "tax base" for green taxes would simply disappear. But don't bet on it.
Most tax proposals envisage that green taxes will simply shift the tax burden: green taxes will rise while other taxes will fall. Whether that's a realistic assumption is doubtful.
But whatever the regime, the government needs money to pay for education, health, defence and the rest of its budget. If the green tax base shrinks, chances are that green targets (and taxes) will be adjusted accordingly.
The UK contributes to a little over 2% of global emissions so how does our paying tax change the behaviour of China, India, the rest of Asia and the USA?
Tim Weber: Well, the UK tax regime hits UK tax payers only - it does not reach beyond the shores of these islands. Having said that, by setting an example the UK might change other countries' behaviour.
Too often governments dodge green laws by insisting that other countries move first. If the UK goes green, other large EU countries are likely to follow suit. And the five-year plans of both China and India already put much more emphasis on protecting the environment.
I drive 37 miles to work every day, I have no choice. My job skills are not needed locally. There is no bus and I work flexi-time so a lift share won't work. Will these "green" taxes take people like me into account?
Tog, Calne, United Kingdom
Tim Weber: You may well be one of the losers of green taxation.
Remember the fuel protests a few years back, when both truck drivers and people living in the countryside protested against high fuel taxes? Given your daily commute, you are very likely to pay more. But don't worry too much yet, the fine print for the green tax regime has not yet been written.
The Earth's climate moves in cycles, we get global warming, we get global cooling. Most this cycle is not 'man-made' but natural. How can you prove that what is happening is man made?
JR, United Kingdom
Richard Black: The Earth has been going through regular cycles of glaciation and warmer periods for at least the last 800,000 years, each cycle lasting for about 100,000 years. The cycling is presumably driven by differences in the amount of solar radiation reaching the Earth's surface, although solar variation is clearly amplified by mechanisms that are not completely understood.
What is happening now does not appear to be part of that cycle. The timing is wrong, the speed of change looks too abrupt:
There is a robust mechanism explaining why elevated levels of greenhouse gases will produce higher temperatures - it is accepted by scientists sceptical of the view that disaster looms.
And there is circumstantial evidence - the fast warming is happening at the one time in those 800,000 years when six and a half billion humans populate the planet, when there has been major loss of forest cover and widespread use of fossil fuels.
The concept of absolute proof is problematical in science - the only thing to do is read the evidence, not the spin, and make up your own mind.
We have massive taxation on petrol, yet people still buy big cars. Nobody buys rubbish to fill their bins, it comes with the products people want. When is the government going to change people's mindset with regard to pollution - rather than just hike taxes?
Scot, London, UK
Richard Black: The government has set up a project and a fund to persuade people of the case for personal action on climate change - you can find details at:
The government would also argue that it is setting an example, by measures including requiring the carbon offsetting of ministerial flights.
Green taxes will not make the slightest difference to climate change. If they want to provide incentives, why don't they REDUCE tax for the lower polluters?
Justin Ticker, England
Tim Weber: That's just what the chancellor did in his most recent Budget, when he dramatically cut the vehicle excise duty for a range of low-polluting cars.
Having said that, an annual saving of £50 or £100 is not nearly enough an incentive to change the behaviour of people who buy high-emission vehicles like four-wheel drives or fast cars.
And if we look at the big ticket items, the recently introduced Europe-wide carbon emissions trading regime actually is some form of tax reduction for lower polluters.
But let's get real: the current green tax regime has failed to make a serious impact on all of us -polluters both big and small.
And if we accept that public services have to be paid from taxes that come from somewhere, then higher green taxes are more likely to do the trick. Let's just hope that the chancellor of the day will reduce other taxes to ensure that overall the tax burden won't rise.
OK, so If air travel is such a bad thing for the environment, as we are being told, can we look forward to the proposed airport expansion schemes in the UK being stopped?
Tim Weber: Good question, but there is no good answer. Right now air travel faces hardly any green taxes.
Ultimately this is about supply and demand. If people fly less, the airport expansion schemes will be redundant. But it will be a bold politician who tells his Ryanair and Easyjet loving voters that their next holiday in France or Spain will cost them much more.
Why aren't the government encouraging the use of ethanol and other bio fuels most diesels can run on them now?
Nicholas Ford, Benfleet, United Kingdom
Tim Weber: For starters biofuels are a pretty expensive way of reducing greenhouse gas emissions. It costs about 35p to produce a litre of biofuel. That in itself is not the problem, though.
To make biofuels a success, three things have to be in place:
- Supply: Farmers first have to produce enough of the stuff; this would require a dramatic restructuring of global agriculture.
- Demand: We would require a massive publicity campaign to persuade consumers to use it and tell them whether their car is suited for this fuel.
- Logistics: The biggest problem, though, will be to persuade the owners of petrol stations - oil companies and supermarket chains - to make the massive investments needed to store biofuel (with a stainless steel tank going for £120,000 a pop). In a limited trial currently running in Somerset it took massive financial incentives to persuade several supermarkets to sell bio-ethanol at their forecourts.
And not everybody believes that biofuels are good for you. Some experts are warning that a massive investment in biofuel could lead to food shortages elsewhere. For now, the government is still trying to make up its mind on biofuels.