Today Donald Trump issued an executive order that starts the process of repealing the Clean Power Plan, a regulation that requires states to reduce the greenhouse gas emissions generated by their existing coal- and gas-fired power plants… The order, notwithstanding the administration’s claims, does not have clear immediate effects on either the fate of the coal industry or the overall economy. But it does signal a determined indifference to the tremendous costs that climate change is already imposing nationwide, and that cities in particular must bear. The attempt to repeal the Clean Power Plan comes as rollbacks of other climate rules are under way, such as fuel efficiency standards for cars and trucks. The administration has also proposed cuts to funding for standard, science-based activities like maintaining weather satellites and mapping floodplains—crucial tools for keeping Americans safe even if our climate and shorelines were stable… Unlike President Trump and EPA Administrator Scott Pruitt, America’s cities cannot afford to indulge in denying the reality of climate change. The heat waves, sea level rise, and extreme weather caused by climate change all threaten Americans’ health and wellbeing, damage and destroy critical infrastructure, and disrupt cities’ economic activity – at great expense. Accordingly, cities have recognized that the costs of adapting to runaway climate change would be catastrophically high, and so are working toward the lower-cost option of reducing the greenhouse gas emissions they generate, even as they prepare for inevitable disasters and the gradual transformation of their environments.