Addressing the U.N. Climate Summit on Tuesday, President Barack Obama said the United States accepts responsibility for its part in climate change and will lead the way in doing something about it. He said the U.S. has cut carbon emissions already and will set new targets to cut even more. Full story: www.pbs.org/newshour/rundown/obama-addresses-u-n-climate-summit/ Subscribe on YouTube: bit.ly/139JZdo Watch more PBS NewsHour videos at: to.pbs.org/1e3qlFJ Follow us on Twitter: twitter.com/newshour Facebook: www.facebook.com/pbs.newshour Google+: plus.google.com/+PBSNewsHour