"Developing nations now emit more than half of mankind's greenhouse gas pollution...The 10 most polluted cities on the planet are all in emerging market or developing countries"

Mongolia's capital tries to shed its smog | MNN - Mother Nature Network

Ulan Bator's air also underscores the increasing contribution of developing world to global warming. Developing nations now emit more than half of mankind's greenhouse gas pollution, fueled by soaring demand for coal, oil and gas to power their booming economies.
...
The 10 most polluted cities on the planet are all in emerging market or developing countries: Iran, Pakistan, India, Botswana and Mongolia. Chronic polluter China no longer has any cities in the top 10.

The Coming Clash Over Global Warming | GoozNews

those who control the political and economic systems of the U.S. are moving inexorably toward ignoring the threat, and doing everything in their power to ensure the U.S. remains an outlier when it comes to uncontrolled dependence on fossil fuels.