There is an effective scheme to preserve tropical forests. It is called debt-for-nature exchange or debt swap. The scheme recognises that many of the countries which are cutting down forests are struggling to repay foreign debts and are desperately in need of the revenue they will get for timber. In debt-swap a rich country agrees to cancel a debt from the poor country if that country will agree to conserve a certain area of forest in exchange. Cameroon and Madagascar in Africa and Costa Rica and Bolivia in South America are some of the countries that have benefited from the scheme. The whole world will benefit if the scheme expands.