This is without doubt the oldest thing in the Museum: it is wood of trees that grew 300 million years ago. These trees were destroyed by a natural cataclysm, were covered by the sea, ended up under layers of sediments, where they became compressed, stretched and transformed in what we now call coal. It is a thing, a hyper-object par excellence, spread in time and space and colluding with every other object.

Human's only interest in coal is to burn it. Burning a cubic meter of coal produces 5 to 6 times more energy than burning  a cubic meter of wood.

The Romans already used coal as a fuel, and in Britain coal mines did exist since the Middle Ages. The demand for coal increased, because most of the forests were already ut, but its extraction in coal mines is limited because of flooding by ground water. The first steam engine (by Newcomen 1712) was used to extract water from coal mines. Coal is used to fuel steam engines. Coal is used to produce more coal. Burning one ton of coal allows the extraction of 80 ton of coal, which can be burned again. This explosive positive feedback loop is the industrial revolution: the possibility to make ever more things , ever faster and bigger.

When coal is burned, CO2, that was captured from the atmosphere 300 Mio years ago to become wood, is re-entering the atmosphere of today. It is entering must faster than that it can be absorbed by the trees growing today. That CO2 thus accumulates in the atmosphere, leads to an enhanced greenhouse effect and global warming.

Climatologist have warned for this more than a century ago. Forty years ago they calculated that in order to avoid dangerous climate change, the use of coal had to be phased out, as well as the use of other fossil fuels like oil and gas.

Only in 2021, humanity, represented by its 197 countries under the umbrella of the United Nations, agreed to phase "down" the use of coal. No word yet about oil or gas, even though today, the burning of oil and gas produces more CO2 than the burning of coal.