Burning all of the world’s currently available fossil fuel resources would result in the complete melt of the Antarctic ice sheet — and lead to a rise in sea levels of more than 50 metres, writes Elke Bunge.
The change in global climate since the 1950s is like nothing ever experienced before: the atmosphere and oceans have warmed, concentrations of greenhouse gas emissions have increased, snow and ice levels have retreated and sea levels have risen.
According to the International Panel on Climate Change (IPCC), sea levels rose a total of 1.9 centimetres between 1901 and 2010. While it is difficult to determine with full certainty future sea level rise,the fifth assessment report of the IPCC predicts a sea level rise of 45 to 82 centimetres by 2100, depending on the climate scenario and the corresponding warming.
Up to 58 metres
In a recent study, researchers from the Potsdam Institute for Climate Impact Research (PIK), the University of Potsdam, Stanford University, the University of Bristol, and the University of California in Riverside developed a scenario in which sea levels could rise by up to 58 metres in the long term.
In their scenario, which was published in the journal Science Advances, the international team of researchers base their prediction on continued rapid consumption of fossil fuels: “If we were to burn all attainable fossil fuel resources, this would eliminate the Antarctic ice sheet,” says lead author Ricarda Winkelmann from the Potsdam Institute for Climate Impact Research.
Goodbye Hamburg, New York and Shanghai
The increase in ocean mass due to ice melt is difficult to predict and the subject of much discussion these days. The research team led by Winkelmann has taken an extreme hypothesis: it calculated sea level rise in the event that humanity burns all remaining fossil fuel resources. This includes not only the economically and technically available reserves on the planet, but also all fossil fuels available on Earth.
“This would not happen overnight, but the mind-boggling point is that our actions today are changing the face of planet Earth as we know it, and will continue to do so for tens of thousands of years to come. If we want to avoid Antarctica to become ice-free, we need to keep coal, gas and oil in the ground,” says Winkelmann. Failure to do so would mean that cities like Tokyo, Hong Kong, Shanghai, Calcutta, Hamburg or New York will disappear forever.
At present, global sea-level rise is mostly driven by thermal expansion of the warming oceans and the influx from melting mountain glaciers. However, Greenland and especially Antarctica with their huge ice volumes are expected to be the major contributors to long-term future sea-level rise, write the researchers.
10,000 million tonnes of CO2
In order to dramatically illustrate the dangers of unrestricted carbon dioxide emissions, the climate scientists took an extreme argument as their starting point.
“The idea was to compute what we have already started by emitting greenhouse-gas emissions from burning coal or oil – and to analyse where that will take us in the future,” says co-author Ken Caldeira of the Carnegie Institution for Science at Stanford University.
The bad news is that burning all available fossil fuel resources would result in carbon emissions of about 10,000 billion tonnes. The ‘good’ news is that according to the latest assessment report of the IPCC, current total anthropogenic emissions (calculated from 1750 to 2011) are 550 billion tonnes. This means that even if emissions continue at such a high rate, it would still take humanity another 5,000 years to ‘accomplish’ the extreme emissions levels estimated by the research team.