Globally the impacts of climate change are likely to disproportionately harm developing nations despite the fact that these nations have contributed little to cumulative greenhouse gas (GHG) emissions. This inequity, the authors of this Tiempo article argue, is compounded by the further injustice of traditional cost benefit analyses of climate change impacts which focus on the monetary value of damage whilst ignoring issues such as distributional inequity and the value of nature or quality of life.The authors propose a more equitable system for assessing climate damages expanding on earlier work by Schneider et al (2000) which proposed five alternative measures to the market value based methodologies of traditional cost benefit analysis. These are:conventional market system costs in dollars per ton of carbonhuman lives lost per ton of carbonspecies lost per ton of carbondistributional effects in changes in income differentials between rich and poor per ton of carbonquality of life changes, such as heritage sites lost or refugees created per ton of carbon.The article proposes that, in addition, the relative costs should also be considered in some of these categories in order to better account for potential damages and to help merge the often disparate values of different groups in gauging damage seriousness. For example, market-system costs relative to a country’s Gross Domestic Product should be considered, or species lost relative to the total number of species in that family.The article goes on to discuss the broad policy alternatives available to nations in addressing climate change from a justice perspective. Cost benefit analysis often assumes that mitigation (abatement) and adaptation are competing strategies for dealing with climate change. This has serious equity implications if, for example, it is cheaper for industrialised nations to adapt to climate change rather than reduce emissions which continue to damage a poorer, less adaptable country.The report concludes therefore that industrialised nations must reduce emissions and help poorer nations to adapt. The authors stress, however, that mitigation in developing countries is also necessary. Specifically they recommend: reducing the rate we add to atmospheric GHG levels will allow time to understand what may happen and to help develop lower cost mitigation options. GHG abatement policies will provide incentives to invent cleaner, cheaper technologies. Industrialised countries should aggressively lead the effort, given their historical contribution to the problem and greater capacity to helpdeveloping country and marginalised group needs should be considered and fulfilled through adaptation and abatement actions coordinated within and among countries. Industrialised countries should shoulder this burden, as required by the UNFCCCdeveloping countries need assurances that national GHG abatement actions will not jeopardise a fair resolution of long-term emissions allocation. Discussions and movement on this issue are urgently needed.