A mere week after The Post commended President Obama for pledging to more vigorously combat climate change [“Warm to the task,” editorial, April 26], it’s astonishing to see the editorial page call anew for the construction of the Keystone XL tar sands pipeline [“Pipeline politics,” editorial, May 2]. The project would threaten America’s heartlands with oil spills that would be difficult to clean up, and it would mean expansion of a high-carbon fuel at a time when our communities are threatened by increasingly violent weather and sea level rise.

Combating climate change — as rightly called for by The Post — means we cannot continue to aid and abet the proliferation of tar sands oil. Tar sands oil is not the right choice for America. Its extraction from boreal forests not only worsens climate pollution but also perpetuates our dependence on ever-more destructive and expensive forms of oil when we need to move to cleaner transportation solutions.

Susan Casey-Lefkowitz, Washington

The writer is director of the International Program of the Natural Resources Defense Council.