A research team led by ex-NASA scientist James Hansen has calculated what today’s children and teenagers will have to pay to bring the climate back into balance because today’s adults didn’t reduce our greenhouse gas emissions in time. The stunning price tag gets as high as US$535 trillion, seven times the world’s annual GDP.
The analysis, published in the journal Earth Systems Dynamics, is intended to support a group of Oregon youth taking the U.S. government to court for failing to protect their future life, liberty, and property by not acting now to check climate change. Failing to do so, researchers from the U.S., France, China, the United Kingdom, and Australia concluded, “would saddle young people with a massive, expensive clean-up problem and growing deleterious climate impacts.”
The estimate is unusual for its focus on the cost of restoring something closer to pre-industrial concentrations of greenhouse gases in the Earth’s atmosphere. The researchers write that if humanity is to escape the intolerable conditions projected at temperatures more than 2ºC above pre-industrial levels, “atmospheric CO2 should be reduced to less than 350 parts per million (ppm) from its present level of about 400 ppm.”
“If phasedown of fossil fuel emissions begins soon,” the study’s authors write in the abstract to their paper, “improved agricultural and forestry practices, including reforestation and steps to improve soil fertility and increase its carbon content, may provide much of the necessary CO2 extraction.”
But if emissions continue growing at the rate of 2% per year that they established over the first 15 years of the century, humanity will need to extract “well over 1,000 gigatonnes of carbon from the atmosphere by 2100” using technological means, the researchers estimated. Based on what they consider the most promising current technology to do that (bioenergy with carbon capture and storage or direct air capture of CO2), the authors estimate the “minimal” cost of the undertaking to future global taxpayers would be US$89-535 trillion, compared to global GDP of $76 trillion in 2013.
If it worked. The researchers also note that those extraction technologies carry “large risks and uncertain feasibility.”
Hansen, former chief climate researcher at NASA and now on the faculty at Columbia University’s Earth Institute, led the study “as part of the scientific basis for legal action in the Juliana et al. vs United States case,” the journal wrote in a release.
“We wanted to quantify the burden that is being left for young people, to support not only the legal case against the U.S. government, but also many other cases that can be brought against other governments,” Hansen said.
The estimate does not appear to include the multi-trillion-dollar cost of adapting infrastructure, economies, and cultural practices to climate-driven change in weather patterns, water resources, and shorelines, or of direct losses due to those changes.