British Airways sent us an email telling us what they are doing to reduce their carbon emissions. Here are their top five environmental measures:

1. Becoming the first airline to set a public target for fuel efficiency (a 30 per cent improvement by 2010, compared with 1990) – and saving 60 million tonnes of CO2 in achieving a 27 per cent improvement to date.

2. Becoming the first airline to join a carbon emissions trading scheme (2002) and understanding that carbon trading is the most environmentally effective way for aviation to combat its impacts on climate change.

3. Leading the successful campaign for the EU to include aviation in its carbon trading scheme.

4. Becoming the first airline to introduce a carbon offset scheme for customers.

5. Funding research into alternative aviation fuels (2001) and pioneering operational practices such as continuous descent approaches to reduce fuel burn and emissions.