Barack Obama

Commencement address to new coast guard cadets warns "climate change constitutes a serious threat to global security-an immediate risk to our national security"

President hits out at elected officials throwing snowballs in Senate during hilarious sketch

Crucial court case gets underway as latest figures suggest US emissions rose once again in 2013

Chair of Clinton campaign reveals action on climate change will be a top priority, fuelling hopes a Clinton presidency would build on recent progress from Obama administration

Bloomberg New Energy Finance predicts 2015 could make a major turning point in US efforts to decarbonise the power sector

President hailed as the greenest in history as White House launches new push to highlight threat to public health from climate change

President signs executive order to cut emissions 40 per cent and use 30 per cent green energy by 2025

Republicans open up new fronts in attempt to stop the Environmental Protection Agency regulating greenhouse gas emissions

GreenBiz's Mike Hower explores how businesses can help the US Congress tackle the climate challenges it faces

President rejects bill approving controversial project, accusing Congress of trying to cut short 'thorough consideration' of the pipeline's potential impacts