Economist Prof Martin Weitzman on climate change


Tim Harford, Financial Times


“The message of Weitzman’s recent work has influenced the policy debates on climate change: the extreme scenarios matter. What we don’t know about climate change is more important, and more dangerous, than what we do.”


One of the most significant examples is the predictions of the amount of tropospheric CO2 in the future. Actually, analysis of the records held by the NASA Earth Observatory  at Moana Loa on Hawaii reveal that the amount of CO2 is rising and the amount of rising is increasing.  It has already hit a tipping point and the amount is unpredictable.  See:



“Weitzman ‘asked us to contemplate the risk of runaway effects’, or ‘tail risks’ that lie well outside the most likely scenarios, such as permafrost thaw, explains Harford. ‘Central estimates can lead us astray,’ says Harford, and’ it is only when we ponder the tail risk that we realise how dangerous climate change might be’. ‘The truly eye-opening contribution – for me, at least – was Weitzman’s explanation that the worst-case scenarios should rightly loom large in rational calculations,’ says Harford.”