U.S. President Obama and President Xi Jinping of China late Tuesday both announced new targets to reduce greenhouse gas emissions. Obama plans to reduce greenhouse gasses up to 28 percent below 2005 levels by 2025, while Jinping hopes to cease the growth of emissions entirely while increasing alternate fuel (non-fossil fuel) shares to 20 percent by 2030, according to a White House fact sheet.

The two countries comprise over one-third of the world's greenhouse gas emissions, so a combined effort to reduce those emissions will have a huge impact globally.

The U.S. plan doubles carbon reduction from 1.2 percent annually between the years 2005 to 2020 to as much as 2.8 percent a year between 2020 and 2025. The plan results from "intensive analysis of cost-effective carbon pollution reductions achievable under existing law and will keep the United States on the right trajectory to achieve deep economy-wide reductions on the order of 80 percent by 2050," according to the fact sheet.