• Action: Climate change will affect us all, but its heaviest costs will fall upon low-income people who live closest to the margin of survival and are least able to afford air conditioners, sea walls and other types of insurance. Climate inaction is climate injustice.

• Adaptation for all: We cannot prevent climate change altogether. Investments in adaptation are necessary, but how should these be allocated? The conventional economists’ prescription is that investments should be guided by ‘willingness to pay’, which of course depends on ability to pay. The implications of this logic were spelled out two decades ago in the Summers memorandum that purported to make the case for dumping toxic waste in low-wage countries. Climate justice requires that investment in adaptation should be guided by human needs, not by the distribution of purchasing power.

• Co-benefits: Burning fossil fuel releases not only carbon dioxide but also copollutants that endanger human health. Co-pollutant damages per ton of carbon dioxide vary greatly, so it makes sense to reduce emissions where the benefits of co-pollutant reductions are biggest. Because co-pollutants disproportionately impact low-income communities and minorities, integrating them into climate policy is a matter of climate justice as well as efficiency.

• Dividends: A cap on carbon emissions is essential, but instead of giving free permits to polluters–a central plank in ‘cap-and-trade’ schemes–polluters should pay. Permits are valuable: their holders will receive the fossil fuel price increases triggered by the cap. They should be auctioned, not given away, eliminating any need for permit trading. The revenues should be returned to the people as the rightful owners of the atmosphere's limited carbon-absorptive capacity (or any country's share of it).