Making our mark – ecological footprints
Box 2 | Tell me about carbon offsets
In the modern world with our deeply ingrained reliance on fossil fuels, it is probably impossible to cut your carbon emissions to zero. Even after making every effort, something will remain. But there is another option being offered as a way to reduce your impact. You can make use of carbon offsets.
Suppose you need to make a plane trip overseas, inevitably leaving carbon dioxide in your wake (plane trips generate about 3 per cent of all carbon emissions). Many airlines now let you buy an 'offset'. With your money, the company can do a variety of things to negate your new contribution to the carbon dioxide burden our atmosphere carries.
For example they can pay someone else to plant trees that can take up and store (or 'sequester') an equivalent amount of carbon dioxide. These need to be new trees of course, not just replacing trees which have just been cut down, though revegetating land that was cleared long ago can constitute an offset.
Offsets can also come from projects that cut the emission of methane (an even more potent global warming gas than carbon dioxide) from livestock, landfills or coal beds. Other options include helping fund projects for renewable energy, like wind, solar or biomass, or projects that promote energy efficiency. Unlike tree planting, these options prevent activities that cause greenhouse gas emissions so can reduce emissions.
Offsets are a relatively new idea, and one that is not yet fully worked out. The standards and regulations are still being developed, and being a largely unregulated market, terms like carbon-neutral are sometimes used inappropriately for commercial gain. In addition, you cannot always be sure your investment will deliver what is promised. Trees planted to sequester carbon dioxide can burn down or will ultimately die, letting the gas back into the air. An investment in 'green energy' might be more certain. Calculations to determine how much carbon dioxide is being saved or stored can be complex and not fully reliable, leading to over-estimations and even double-counting.
Yet offsets are probably here to stay, and they will become more effective and accepted as we sort out the problems. They will form a big part of the carbon trading regimes proposed for Australia and elsewhere, with both individuals and companies taking them up. Companies to broker offsets are now being set up. In principle, at least, they allow emissions to be cut at a relatively low cost, so have less impact on the economy than other means of reducing emissions. Offsets are a part of the solution to climate change; ultimately, we need to reduce our reliance on fossil fuels.
Boxes
Box 1. Sustaining our forests
Box 3. What difference can we make?
Related sites
Carbon offsets compared (Choice, Australia)
How carbon offsets work (How Stuff Works, USA)
Look, no carbon footprint (New Scientist, 9 March 2007)
Greenfleet (Greenfleet, Australia)
Would you pay to offset your air travel emissions? (Ecos, April-May 2007)
Carbon offsets – the facts (New Internationalist, July 2006)
10 things you should know about tree 'offsets' (New Internationalist, July 2006)
Posted December 2008.