Gov. Brown has unveiled a new cap-and-trade proposal for California. Here’s why there’s tension behind the plan

The state is responsible for a tiny fraction of the world’s greenhouse gas emissions, meaning its only hope of influencing global warming is modeling policies that can be embraced elsewhere, including in more conservative states. Cap and trade, a system that requires companies to buy permits to release greenhouse gases, is seen as a more business-friendly alternative to other methods that would dictate how polluters such as refineries reduce their emissions. “Being able to show that [emissions] reductions can happen, that the economy can continue to thrive with this ambitious climate commitment, that’s going to be critical for this model being replicated around the world,” said Erica Morehouse, a senior attorney with the Environmental Defense Fund, a national environmental group that quickly backed Brown’s plan.