Economic inequalities have been behind the failure of many efforts to develop international cooperation to reduce carbon emissions and save the climate. At COP 26 in Glasgow, just as at COP 21 in Paris and COP 3 in Kyoto, poor countries insisted that they had the right to burn fossil fuels in order to end poverty, just as the rich countries had done. After Kyoto, rich countries complained at the exemptions granted to poor countries, and the US never ratified the Kyoto treaty, thus condemning it to failure. The Paris agreement is still in the balance because of the same problem. The article by Lucas Chancel "The richest 10% produce about half of greenhouse gas emissions. They should pay to fix the climate" (Guardian, December 7th) shows convincingly how inequality is an obstacle to the reduction of carbon emissions not only between nations but also within them. More important, he helps to unlock the impasse with examples of intelligent policies in places like Canada and Indonesia which overcome this obstacle.