i've lived in quite a few countries (countryside and cities), and it's the first time i read about it. i know about burning wood for heating (done that for a while), but burning coal never. you live and learn :)

Coal is more efficient in our winters. You can load a stove with coal and it keeps you warm all night which is not as easy with wood.

It is acctually a paradox here in Poland. I live in suburbs outside of Warsaw, surounded by forrest and still sparsely populated. People are building new houses here to get out of the city and pollution. They build heatpumps (or somerhing else) but also a fireplace as a secondary heating source. Then they learn to discover that coal is cheap, accesible and more energy efficient (more convinient) in winter.

As a result in winter at evenings you get smog and filthy air in suburbs worse then in the city center.

Well, coal is better than wood, but it so happens that some people in countryside have ample supply of free-ish wood :). I know some people who burn wood most of the year, and only add coal to the mix during winter.