Immediate fossil fuel phaseout could arrest climate change
The study found that if all fossil fuel infrastructure – power plants, factories, vehicles, ships and planes – from now on are replaced by zero-carbon alternatives at the end of their useful lives, there is a 64% chance of staying under 1.5C.
The study, published in the journal Nature Communications, used computer models to estimate by how much global temperatures would rise if a fossil fuel infrastructure phaseout began immediately. The lifespan for power plants was set at 40 years, cars an average of 15 years and planes 26 years. The work also assumes a rapid end to beef and dairy consumption, which is responsible for significant global emissions.
In this scenario, the models suggest carbon emissions would decline to zero over the next four decades and there would be a 66% chance of the global temperature rise remaining below 1.5C. If the phaseout does not begin until 2030, the chance is 33%.
The analysis did not include the possibility of tipping points such as the sudden release of huge volumes of methane from permafrost, which could spark runaway global warming.
The scientists accept their scenario is at the extreme end of ambition, but said it was important to know that meeting the 1.5C target was still physically possible and dependent on the choices made now and in the coming years. “The climate system is not stopping you [hitting the target], global society is stopping you,” Smith said.