Felling the world's tropical rainforests accounts for as much as a quarter of greenhouse gas emissions – more than all the CO2 pumped out by trains, planes and motor vehicles.

So one of the most effective ways we can reduce carbon emissions is to stop the world's rainforests being felled.That's why the Marriott hotel chain has pledged US$2 million dollars to support the Juma Reserve in Amazonas in what is claimed to be a pioneering conservation agreement between government and private enterprise.