Spontaneous coal fires in heaps and beyond – a forgotten factor of the dynamics of climate change

Spontaneous coal fires are known from both post-coal mining waste-rock heaps and natural geoenvironments. They represent a still not fully scientifically encompassed phenomenon. They are very difficult to be fully contained, thus sustaining long-time emissions in the heaps. Some of them may burn for 70 years and more. As a worldwide issue, both from environmental and human safety point of view, these fires pose a forgotten factor of the dynamics of coal fires, as they add to the worldwide CO2 emissions' budget. However, CO2 is just a tip of an iceberg in these emissions, as shown here by the example of the Upper Silesian heaps of Poland.