It's nothing but hot air.
From the Daily Caller:
President Barack Obama and Chinese President Xi Jinping ostensibly agreed to cut greenhouse gas emissions in the coming decades to fight global warming. As with many international agreements, the devil is in the details.
The White House’s climate deal with China would have the U.S. cut its emissions 26 to 28 percent below 2005 levels by 2025 — something the Obama administration already plans to do under its Climate Action Plan. But while the U.S. has to cut back its fossil fuel consumption and suffer through artificially higher energy costs, China only made vague promises of emissions cuts.
China can emit all the greenhouse gases it wants until 2030, while giving no firm commitment on where its emissions level and how much it will reduce its dependence on fossil fuels. China only promised its "best efforts" to peak emissions while boosting its green energy use by 2030.