The Arctic ice stores roughly 50 billion tons of methane, a concentrated gas some 20 times more powerful than carbon dioxide. Over the past few years, scientists have observed the gas pluming from the region’s thawing ice. That raised the question: even as profits are hauled in from shipping and drilling in the Arctic, could that methane gas be waiting to undo all those gains? Could the toll of that released gas far outweigh the rewards of melting Arctic’s ice?
Researchers used what is called the PAGE09 model to assess a broad range of risks arising from methane gas release. Their work is built on the 2006 Stern Review on the Economics of Climate Change’s model, which judged the economic effect of extra greenhouse-gas emissions on such factors as sea level rise, temperature, and extreme weather risk. That model found that, as a result of global warming, the world would incur a total cost of $450 trillion by the end of the century.
But seven years ago there was too little research on methane gas in the Arctic to include in the model its influence on the global economy, Dr. Whiteman said. So this time, scientists modeled a 10-year release of the 50-billion-ton methane bubble between 2015 and 2025 and showed the effects of that decade-long burst until 2200. The model was based on the current rate of greenhouse emissions.
The team found that methane release from just the melting permafrost beneath the East Siberian Sea would accelerate the rise in temperatures to 3.6 degrees Fahrenheit above preindustrial levels to 2030. That increase in temperatures would cost the world some $60 trillion – a sum almost as large as the size of the entire global economy last year, totaled at about $70 trillion. It is also an added cost of about 15 percent to the already $450 million in damages that the Stern model had found in 2006.
“Without question there are some gains for some industries and some countries – but that doesn’t take into account climate change’s negative impact throughout the entire world,” said Whiteman.
That $60 trillion sum is a mean number based on the estimated – but still unknown – amount of methane in the Arctic. That puts the lower and upper boundaries of the total cost at $10 trillion and $220 trillion. The model was also based on a 10-year burst of methane beginning in 2015, but when and over what length of time methane seepage might occur is still unknown.