It was when the Kyotoaccord was first signed in 1997 that George started thinking of new ways to sell carbon credits and started researching iron fertilization.
The three dozen or so rich countries that signed the Kyotoaccord agreed to lower their emissions of greenhouse gases by at least 5% below 1990 levels by 2012 but did not specify how.
Mr Grubb shows why it is right to be concerned about such practical difficulties but also why they do not undermine the success of the Kyotoaccord, which they take to be one of the great negotiating successes of the past half-century.