[Bloomberg View ] Cass Sunstein: This week’s decision by the Environmental Protection Agency, imposing a new limit on ground-level ozone at 70 parts per billion, was eminently reasonable -- an impressive vindication of both law and science. The loud objections, coming from both the business community and environmental groups, are unconvincing. (Disclosure: As administrator of the White House's Office of Information and Regulatory Affairs, I was involved in the 2011 decision to postpone the ozone regulation.)

[Foreign Policy ]...“The complaints, from people in Congress and elsewhere, [were], ‘Okay, so they’ve given an aspirational target, but they haven’t said how they’re going to do it.’ Well, now they’ve done precisely that, and that’s extremely important,” said Robert Stavins, director of the Harvard Environmental Economics Program.

[Bloomberg View ] Cass Sunstein: This week, Pope Francis is expected to implore both the U.S. Congress and the UN General Assembly to take aggressive steps to curb greenhouse-gas emissions. His thinking on this issue is not simple alarm over climate change. It involves an extraordinary combination of passionate environmentalism, concern for the poor, skepticism about economics and apparent hostility to "profits." All this makes for an impressive but occasionally awkward argument.

[Robert Stavins' blog] The upcoming Paris climate negotiations will constitute a critical step in the ongoing international process to reduce global greenhouse gas (GHG) emissions. The question of whether the Paris outcome will be sufficiently ambitious to put the world on a path towards limiting global average warming to 2^o C, as agreed in Cancun, can be answered now.  It will not, because that target, while possibly useful as an...