I suspect that the real reason is that the government are protecting the coal industry to save jobs,
I agree with you. Let's face it, no government is going to want to close mines and put people out of work, it didn't exactly go down well in the UK.
According to this article, Poland now has the worst air pollution in Europe:
thenews.pl/1/9/Artykul/396103,Poland%E2%80%99s-air-pollution-worst-in-Europe-auditors
Although Duda seems to think that burning stuff other than coal is the problem. "May every single citizen think again before they heat their homes with trash or plastic," he stated in the article. I agree that this is also a big problem, but no mention of the burning of coal at all. Hmm. Plus, a couple of days before the climate conference, the deputy energy minister announed that a decision would be taken next year to build a new coal mine. I think it's safe to say that Poland is not giving up its coal industry no matter what the cost to health and the environment.
Also from that article, Duda said: "Climate protection is the concern of every household, every farm." In fact, it wasn't long before the climate change conference that the Polish government was calling for more trees to be planted worldwide to help combat carbon emissions. A bit ironic considering the decimation of huge swathes of the Białowieża forest. You really couldn't make this stuff up.