Daily human activities increase atmospheric carbon dioxide levels and are feared to speed up the rate of global warming. The average family produces 3 tonnes of CO2 a year, but there are several measures (in addition to reducing individual energy consumption) that environmentalists say offset this so-called 'carbon footprint'.
Planting trees Trees may help reduce global warming by absorbing carbon dioxide and producing oxygen. Some organisations will plant trees on your behalf.
Buy carbon credits A carbon credit is registered by any activity which keeps 1 tonne of carbon dioxide out of the atmosphere for a 100-year period. Various companies will undertake such activities on your behalf, for about $140.
Investment Options include renewable energy sources, biomass fuels, waste-to-energy products, recycling and fuel-efficient vehicles.
Donations Not just the cash kind - for instance, some groups advocate donating energy-efficient light bulbs to developing countries to counteract your own carbon emissions.
Source: carbonplanet.com, carbonfootprint.com