The potential impact of climate change is not a core national issue that outranks economic, military or other key national policies for most countries. Thus, organizing a global, legal agreement at the UN Climate Summit in Paris in late 2015 will not be easy. Though most countries will adopt some measures to comply with UN mandates, they are unlikely to put other national interests in jeopardy. As with many bilateral or multilateral deals, countries will prioritize their domestic interests above all else.

UN member nations are often hesitant to sign legally binding deals. It is hard for a country to predict the challenges its economy or society will face in 2025. Therefore, signing a legally binding agreement that limits coal consumption or greenhouse gas emissions, while setting firm targets for renewable energy standards for 2025, limits the ability to counteract unforeseen problems. This is why setting a target remains tenable, but making it strong and binding is problematic.