Fifty percent of the world's population lives in cities. In a couple of decades, 70 percent of the world's population will be living in cities. Cities are where the problem is. Cities are where the solution is, where creativity exists to address the challenges and where they have most impact. This is why, in 2005, the C40 was founded, an organization of cities that address climate change. It started with 18 cities; now it's 91. Cities simply are the key to saving the planet.

We're paying more for the privilege of getting sick and dying early. Once again, it makes no sense. And once again, no one in Washington is talking about how to fix it.

There are lots of threats to you in the world. There's the threat of a heart attack for genetic reasons. You can't sit there and worry about everything. Get a life.

Look, we live in a very dangerous world. We know there are people who want to take away our freedoms. New Yorkers probably know that as much if not more than anybody else after the terrible tragedy of 9/11.

Whatever you may think of the proposed mosque and community center, lost in the heat of the debate has been a basic question: Should government attempt to deny private citizens the right to build a house of worship on private property based on their particular religion?

If a hurricane strikes, we can blame the president for not being there; we can blame Congress and FEMA; we can blame the state governments; but in the end, it's the mayors and the local city governments that have to be prepared for emergencies and be prepared to act.

Millions of Americans have contributed to building a stronger Israel; I've been proud to be one of them. Last year, I went to Jerusalem to help dedicate in my father's name a new MDA medical facility which treats people of all faiths and all nationalities absolutely equally.