There are fires in Kiev, chaos in the Middle East and challenges at home and abroad, but is the biggest threat to our national security... something else?
Saying that climate change ranks among the world's most serious problems - such as disease outbreaks, poverty, terrorism and the proliferation of weapons of mass destruction - U.S. Secretary of State John Kerry called on all nations to respond to "the greatest challenge of our generation." FULL STORY
In the Crossfire, State Department Adviser Joe Cirincione and The Weekly Standard Editor Bill Kristol join Van Jones and Newt Gingrich to debate.
Gingrich has already been outspoken on the issue, calling for Kerry's resignation over Twitter.
We want you to weigh in: Secretary Kerry says climate change is 'perhaps the most fearsome weapon of mass destruction.' Do you agree?
Author, documentary filmmaker, historian, Speaker of the House (1995-1999), and 2012 Republican presidential candidate
Fmr. Obama Deputy Campaign Mgr. and W.H. Sr. Adviser, founder of Precision Strategies, fmr. Sr. Adviser to Maj. Leader Reid and Sen. Kennedy
Conservative columnist for New York Daily News, contributing editor at Townhall Magazine, commentator and author
Former Special Adviser for Green Jobs under President Obama, co-founder of Rebuild the Dream, author and attorney