Tony Blair's marathon 19-hour flight to Australia will be "offset" to make up for the carbon emissions created, Downing Street has confirmed.
Tony and Cherie Blair have flown to Auckland, New Zealand
But rather than planting trees, the government will make an investment in "energy-saving technology" in the developing world.
A spokeswomen said that from 1 April all ministerial air-miles will be offset in a similar way.
Tony and Cherie Blair are on a tour of Australia, New Zealand and Indonesia.