2 degrees Celsius – that's how much our global temperature has risen in the last century. The main culprit? Emissions and pollution.

That's why changing light bulbs and recycling alone won't save us. To reverse climate change, we need bigger, broader, and long-lasting action – the kind that comes only from international agreements.

This December, delegates from around the world are meeting in Copenhagen to figure out a climate treaty that will address this exact challenge. Their goal: to get all countries, industrialized and developing, to dramatically reduce emissions and greenhouse gases by 2020.

But if the U.S. doesn't lead the process, the treaty will fall flat. Please sign our petition and urge President Obama to support and sign a robust international climate treaty. It's the only way we can stop climate change in its tracks.