It has been done to raise awareness of how much carbon dioxide  has been released  since the start of the  industrial revolution. When the coal will be used depends on how well we are doing to cut back on the use of fossil fuels.

Incidently, as an individual, if you were able to cut your carbon emissions to zero for the rest of your life (which you can’t), it would delay the process of global warming for around two seconds so it is important that everyone works together to reduce the total quantity of carbon dioxide released in the future.

At present, we are around the half-way stage. Since 1750 to the present researchers estimate that around 0.5 trillion tonnes of carbon dioxide have been released into the atmosphere raising the temperature of the atmosphere by around  1 degree Centigrade.

At our present rate of emission of CO2 the science museum will keep the coal until sometime between 2020 – 2050. By the time we reach 1 Trillion tonnes of carbon dioxide, we will have crossed the threshold of temperature change which many scientists consider to be a dangerous level for climate change on the Earth. If we are to keep below this threshold the science museum must keep the coal forever.