File Photo: US President Barack Obama (Associated Press)
US President Barack Obama's determined efforts to combat global warming face their biggest trial yet as opposition Republicans take full control of Congress.
Republicans have promised to send Obama a barrage of bills to roll back his environmental rules and force his hand on energy development. Republican leaders will be able to send bills to Obama's desk unimpeded by Senate Democrats, now in the minority, for the first time in Obama's presidency.
Success for Republicans would jeopardize a key component of Obama's legacy. And the ramifications would likely ricochet far beyond the United States.
Later this year, nations are supposed to sign a major global climate treaty in Paris. If Obama can't make good on commitments he has already made at home, it's unclear whether other countries will feel compelled to act.