I know that many Irish-born New Yorkers are caught in the trap of our federal immigration policies. If we are going to continue to attract the best and the brightest - and Ireland has more than its fair share - we need to inject some common sense into our immigration laws, and I'm doing my best to make that case in Washington.

I've got the greatest job in the world. There's no other job in government where cause and effect is so tightly coupled where you can make a difference every day in so many different ways and in so many different people's lives. It's a great challenge.

Nobody's going to elect me president of the United States.

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.

I believe in Judaism, I was raised a Jew, I'm happy to be one - or proud to be one.

You have to understand, we have better communications and better transportation, so people know what's available elsewhere and can get a message out, and you can move things. And you [can] say that the economy is more unpredictable.

Fighting climate change isn't just an obligation we owe to future generations. It's also an opportunity to improve public health - and drive economic growth - in the here and now.