Professor Myles Allen:

They are treated pretty much identically at present. I do not want to spend a long time on this because I do not think it is particularly pertinent to the Irish situation. In 1,000 years' time, it will be the methane released from mining that we will care about. It will not be methane any more. It will be carbon dioxide because it will have oxidised in the atmosphere. It is the carbon dioxide that is our long-term multi-century legacy.