Joe Biden under pressure from left on climate change

Democratic 2020 frontrunner Joe Biden was forced into defending his environmental record Tuesday after a popular progressive in Congress demanded presidential hopefuls abandon a "middle-of-the-road" approach to combatting climate change."You never heard me say middle of the road.The 29-year-old House Democrat bemoaned lawmaker inaction 30 years ago -- when Biden served in the Senate -- as US space agency NASA warned them about the existential threat of climate change.