Climate change was not a popular topic for the White House in 2012, given, in part, that President Obama hoped to win the still-coal-friendly swing state of Ohio and Virginia. Its absence from the campaign trail was noted in press reports at the time.

But we wanted to quantify just how little the White House talked about it then -- and how much more they are talking about it now. So, we took a look at the administration's press room archives to get a picture of how Obama's eagerness to tackle the subject has evolved over time.  Here's a count of the number of press room updates mentioning "climate change" (as a phrase) each day from August 1, 2010 to last Friday. This offers a fairly rough guideline of how frequently the White House brought up the subject (including in response to questions from the press or in discussions with other world leaders.)

You can see the trend a little more clearly in the graph below. The red line shows the trend over the course of the three-plus years: a number of mentions in 2010, fewer in 2011 and 2012, and increasing mentions in 2013 and 2014.

The point to take away from this is simple. The reason Obama didn't mention climate change on the campaign trail is that the topic is politically fraught — as we've seen in the aftermath of the EPA announcement. Obama, in his sixth year in the White House, doesn't need to risk the political fall-out of a proposal that will come under a lot of fire.