John Kerry, U.S. special presidential envoy for climate, talks about the progress being made on a global scale to combat climate change, reduce reliance on fossil fuels, and transition to a green energy economy, presenting a generally optimistic picture as long as key commitments are made and kept.  » Subscribe to MSNBC: on.msnbc.com/SubscribeTomsnbc Follow MSNBC Show Blogs MaddowBlog: msnbc.com/maddowblog ReidOut Blog: msnbc.com/reidoutblog MSNBC delivers breaking news, in-depth analysis of politics headlines, as well as commentary and informed perspectives. Find video clips and segments from The Rachel Maddow Show, Morning Joe, The Beat with Ari Melber, Deadline: White House, The ReidOut, All In, Last Word, 11th Hour, and Alex Wagner who brings her breadth of reporting experience to MSNBC primetime. Watch “Alex Wagner Tonight” Tuesday through Friday at 9pm Eastern. Connect with MSNBC Online Visit msnbc.com: on.msnbc.com/Readmsnbc Subscribe...