Protesters,some wearing face masks and holding back balloons, gathered as temperatures fell below -20 degree Celsius.Ulaanbaatar, one of the world's coldest capitals is also one of the most polluted cities in the world, according to UNICEF. Many residents burn polluting fuels to keep their homes warm. Residents can't afford to use alternatives to warm themselves up. It's the second protest during this winter in Mongolia. 

Do you have any green ideas which can be used as alternatives of burning fuels?? Comment your ideas please.