60 second guide to... Carbon offsetting

Carbon offsetting has become big business as more individuals and companies seek to shrink their carbon footprints, but does it really work?

What is carbon offsetting?

Carbon offset projects allow us to invest in emission reduction schemes – usually in developing countries – with the aim of reducing our carbon footprints. These schemes aim to either cut future emissions – by distributing energy saving technologies – or to absorb carbon dioxide directly from the air by planting trees.

Some people offset their entire carbon footprint, while others try to neutralise the impact of a specific activity. Before going on holiday, you might visit an offset website to calculate the emissions generated by your flight and then pay to offset them – to make the trip 'carbon neutral' .

Over the past few years, carbon offsetting has become increasingly popular, but it is also becoming increasingly controversial.

Where does your money go?

In the early days of offsetting most schemes focused on planting trees. That's because trees extract CO2 from the atmosphere as they grow and convert it into carbon, which is stored in their foliage, branches and trunks. But there are two serious problems with this approach.

First, it can take decades for a tree to soak up the promised volume of CO2 – not ideal considering the urgency of tackling climate change. Second, the tree will eventually die, at which point much of the carbon it absorbed will escape back into the atmosphere.

Some commentators have also claimed that planting forests in developing countries adds up to a form of "eco-colonialism". Is it right, they ask, for Western organisations to determine how land is used overseas?

As a result, most of the best-known carbon offset schemes have now switched from tree planting to energy saving. For example, Climate Care distributes efficient cooking stoves to families in Mexico and Honduras.

Energy-based projects such as these are designed to make carbon savings more quickly and, as a bonus, offer clear social benefits. For instance, efficient cooking stoves can help poor families save money on fuel and improve their household air quality – a serious health issue in many countries.

Solution or plaster on the wound?

Nevertheless, many critics argue that all offsetting is unhelpful, and possibly counterproductive, in the fight against climate change. They see it as a way for rich Westerners to continue polluting, saying it alleviates guilt without tackling the fundamental problem of reducing carbon emissions.

Environmental writer George Monbiot is one such critic, describing offsetting as "like pushing the food around on your plate to create the impression that you have eaten it".

The spoof website CheatNeutral, meanwhile, ridicules the offsetting concept by enabling people to offset infidelity by contributing money to others who promise to remain faithful or single.

Some offsetters accept these criticisms and respond by offsetting a multiple of their emissions. If a flight causes the equivalent of 1 tonne of CO2, they might offset 5 tonnes – the idea being to make a substantial reduction of CO2 each time they fly.

What's the real price of carbon?

Most offset schemes charge as little as £7 to offset each tonne of CO2. At this price, a return flight from London to New York clocks in at around £12 per ticket.

Many people new to offsetting are surprised at such low prices. If it’s so bad for the environment to fly, can a few pounds really be enough to counteract the damage?

The answer is that there are currently all kinds of ways to reduce emissions cheaply. After all, a single low-energy light bulb costing £1 can save 250kg of CO2 emissions over its lifetime – equivalent to flying return from London to Berlin.

Many offset schemes are externally audited, which should ensure that they achieve the carbon reductions they promise. But some environmentalists claim this misses the point.

They argue that these environmental projects should be happening anyway, funded by governments worldwide, while companies and individuals take steps to reduce their own carbon footprints.

The debate surrounding carbon offset services is likely to run and run. But most people – including the offset companies themselves – agree that offsetting emissions is less desirable than not causing the emissions in the first place.