We're all offsetters now.
Indeed we are. Carbon offsetting has been one of the biggest business stories of the year and the trend has gone so mainstream that thousands of people can even expect to get offset tokens in their stockings for Christmas. Experts are predicting the global market for voluntary offsets will be worth $4bn by 2010.

$4bn, really?
According to the FT, and it's pretty plausible when you think about it. Both consumers and corporations want to be green and paying for a project that will either remove your emissions from the atmosphere or ensure that an equivalent quantity of emissions are not released offers an easy way to bolster green credentials. Everyone's at it, from Sky to HSBC to Dell to your conscientious holiday maker or business traveller. The market is booming and organisations such as Climate Care, The Carbon Neutral Company, Pure and Carbonfund.org are fast becoming household names.

Sounds great.
Yes, it would be if there was any confidence that offsetting actually worked.

Erm, you mean it doesn't? I've just paid 80 pence to offset a flight to Paris.
You should have taken the train. There really isn't much agreement over whether it works or not. Critics claim that there are many instances where you end up investing in emission projects that would have gone ahead anyway so there is no additional benefit. There are also concerns that some firms use calculations for the emissions impact of flight that are inaccurate, that some unscrupulous carbon project managers have sold the same unit of offset carbon twice over, that projects may fail to deliver expected emission reductions, and that some initiatives may even damage local communities.

But surely if you go with a reputable provider they make sure these things don’t happen?
In theory, yes. All the decent providers go to great lengths to promote the various protocols they adhere to when authorising investments and running carbon offset projects and many of them do greatly limit the risk that the money is being wasted. But unfortunately even some of the more reputable providers have been caught out funding projects that appear pretty flawed.

So what's being done about these problems?
The government has actually moved surprisingly quickly on this one and has developed a voluntary code of best practice for the industry so stringent that only a handful of offset companies operating in the UK would currently comply. It's only at the consultation stage and the final version is likely to be watered down a bit, but the whole offset industry is in broad agreement that there is the need for an independent standard that will hopefully be seen as gold label by customers.

Great. Any offsets I buy in the future will have the government seal of approval?
That, of course, would be good but I'm afraid it's unlikely to completely guarantee you will successfully offset your carbon emissions. The standards the government are using are based on the UN's Clean Development Mechanism, which has also been subject to criticism for failing to properly police carbon reduction projects' claims. What's more some scientist's think the whole concept offsetting is inherently flawed.

How so?
They think that it distracts people from the serious task of reducing carbon emissions. What's more they also reckon that no matter how many safeguards you put in place there is no way of guaranteeing emissions reductions. If you take tree planting as the most obvious example the calculations are based on assumptions the trees live for 100 years, but unless you have a crystal ball you can't guarantee that. There are also concerns investing in offset projects could do more harm than good because the money saved through any energy efficiency improvements simply gets re-invested elsewhere. This new investment, or multiplier effect to give it its proper name, could inadvertently lead to an increase in emissions.

Now I'm confused, should I offset or not?
Well it's up to you. Many people, including a recent cross party committee of MPs, argue it is a valid means of limiting carbon emissions and can play a key role in tackling climate change. However, you do need to be aware that there are major risks attached to any investment in offsetting which can be limited, though not eradicated, by going with well managed projects that are frequently audited. Also you need to accept that offsetting can never be an effective substitute for reducing your emissions in the first place. I'm afraid it is just not possible to really "neutralise" your carbon emissions.