New work demonstrates the planet’s remaining fossil fuel resources would be sufficient to melt nearly all of Antarctica if burned, leading to a 160 to 200 ft rise in sea level. Because so many major cities are at or near sea level, this would put many highly populated areas where more than a billion people live under water, including NYC and DC.
“Our findings show that if we do not want to melt Antarctica, we can’t keep taking fossil fuel carbon out of the ground and just dumping it into the atmosphere as CO2 like we’ve been doing,” Caldeira said. “Most previous studies of Antarctic have focused on loss of the West Antarctic Ice Sheet. Our study demonstrates that burning coal, oil, and gas also risks loss of the much larger East Antarctic Ice Sheet.”
Although Antarctica has already begun to lose ice, a complex array of factors will determine the ice sheet’s future, including greenhouse gas-caused atmospheric warming, additional oceanic warming perpetuated by the atmospheric warming, and the possible counteracting effects of additional snowfall.
The team used modeling to study the ice sheet’s evolution over the next 10,000 years, because carbon persists in the atmosphere millennia after it is released. They found that the West Antarctic ice sheet becomes unstable if carbon emissions continue at current levels for 60 to 80 yrs, representing only 6- 8% of the 10,000 billion tons of carbon that could be released if we use all accessible fossil fuels…..”if we want to pass on cities like Tokyo, Hong Kong, Shanghai, Calcutta, Hamburg and New York as our future heritage, we need to avoid a tipping in East Antarctica,” Levermann said.
The team found that if global warming did not exceed the 2 degC target , Antarctic melting would cause sea levels to rise only a few meters and remain manageable. But greater warming could reshape the East and West ice sheets irreparably, with every additional tenth of a degree increasing the risk of total and irreversible Antarctic ice loss.
This is the first study to model the effects of unrestrained fossil-fuel burning on the entirety of the Antarctic ice sheet. The study does not predict greatly increased rates of ice loss for this century, but found that average rates of sea level rise over the next 1000years could be about 3cm/yr leading to 100feet of sea level rise by the end of this millennium. Over several thousand years, total sea level rise from all sources could reach up to 60 meters (200 feet). https://carnegiescience.edu/node/1881
This chart shows how Antarctic ice would be affected by different emissions scenarios. (GtC stands for gigatons of carbon.) It is provided courtesy of Ken Caldeira and Ricarda Winkelmann. Credit: Ken Caldeira and Ricarda Winkelmann
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