We must leave fossil fuels in the ground. Scientists are calling for it
Environment — di Valentina Neri
We can no longer afford to burn fossil fuels — or even to extract them. Scientists have spoken out in unequivocal terms.
We must leave fossil fuels in the ground. Scientists are calling for it
We can no longer afford to burn fossil fuels — or even to extract them. Scientists have spoken out in unequivocal terms.
The global average temperature can rise by no more than 1.5 degrees Celsius above pre-industrial levels. If it exceeds this threshold, the consequences for our planet will be catastrophic and irreversible. The scientists of the Intergovernmental Panel on Climate Change (Ipcc) have made this abundantly clear, and the international community also acknowledged it by signing the Paris Agreement. But what needs to be done, in concrete terms, to honour this promise? Can fossil fuels still be exploited to produce energy, or must they be set aside once and for all? A study published in Nature provides an answer.
Fossil fuels must stay where they are
To have a 50 per cent chance of keeping global warming within 1.5 degrees Celsius, the authors explain, no more than 580 gigatonnes of CO2 can be emitted between now and 2100. This means that, for the vast majority, fossil fuels will have to remain where they are. That is, underground. Regardless of whether they are destined to be burned or not, they should not even be extracted. To be precise, we will need to forgo 89 per cent of coal reserves (826 billion tonnes), 59 per cent of natural gas reserves (92 trillion cubic metres) and 58 per cent of oil reserves (744 billion barrels). It may make sense to exploit only those that are particularly inexpensive — certainly not Canada's oil sands, the Arctic oil and gas fields, or Australia's coal mines.
Climate catastrophe is a risk we cannot afford
The researchers took their cue from a similar study dating back to 2015, which reached less drastic conclusions. It suggested keeping underground a third of oil reserves, half of natural gas reserves and more than 80 per cent of coal reserves, with significant differences from country to country. In that case, however, the aim was to keep global warming within 2 degrees Celsius. This is a target that no longer appears acceptable, as it corresponds to an "incredibly significant" level of warming, clarifies lead author Dan Welsby of University College London.
At first glance, this more up-to-date study looks like a death sentence for the oil industry. In reality, the estimate should be considered conservative: to have a greater chance of saving the climate, we will need to impose even stricter limits.