"Facts, evidence, reason, logic, an understanding of science. These are good things. These are qualities you want in people making policy. These are qualities you want to continue to cultivate in yourselves as citizens.
"That might seem obvious... We traditionally have valued those things; but if you are listening to today's political debate, you might wonder where this strain of anti-intellectualism came from.
"So, class of 2016, let me be as clear as I can be. In politics and in life, ignorance is not a virtue. It's not cool to not know what you are talking about. That's not keeping it real or telling it like it is. That's not challenging political correctness. That's just not knowing what you are talking about. And yet we've become confused about this.
"When our leaders express a disdain for facts, when they're not held accountable for repeating falsehoods, and just making stuff up, while actual experts are dismissed as elitist, then we've got a problem.
"The debate around climate change is a perfect example of this... Every day there are officials in high office, with responsibilities, who mock the overwhelming consensus of the world's scientists; as human activities and the release of carbon dioxide and methane and other substances are altering our climate in profound and dangerous ways.
"A while back you may have seen a United States Senator trotted out a snowball during a floor speech in the middle of winter as proof that the world was not warming [audience laughs].
"I mean, listen, climate change is not something subject to political spin. There is evidence. There are facts. We can see it happening right now. If we don't act, if we don't follow through on the progress we made in Paris, the progress we've been making here at home, your generation will feel the brunt of this catastrophe.
"So it is up to you to insist upon and shape an informed debate... We have to use our heads. We have to agree that facts and evidence matter. And we have to hold our leaders and ourselves accountable to know what the heck they are talking about."