In 2013, the world spewed nearly 40 billion tons of carbon emissions into the atmosphere. Climate scientists overwhelmingly agree that the greenhouse gas will cause a slew of future problems, from rising sea levels to warmer worldwide temperatures. But also included in those worries are the economic costs of carbon dioxide emissions. Known as the “social cost of climate change,” this measurement looks at the damage rising temperatures can create for human health and crop yields, and estimates the monetary cost of each ton of carbon waste. Right now the Obama administration pegs that number at $37 for every ton, but according to a new study, that price tag may be much lower than the actual cost.
Researchers from Stanford University found that the current price of climate change is more likely six times as much, approximately $220 for every ton of carbon produced. Using a new model to calculate the number, the researchers took into account the economic damage that catastrophic climate events, like storms or crop loss, could pose to a country’s GDP over time. “If climate change affects not only a country's economic output, but also its growth, then that has a permanent effect that accumulates over time,” Frances Moore, co-author and environmental scientist, said. Their findings appeared Monday in the journal Nature Climate Change.
The Stanford study, like many others that calculate the social cost of climate change, has several variables in need of further investigation, and may not be completely accurate some researchers point out. “To me, it just seems like it has to be an overestimate," said William Pizer from Duke University, to ClimateWire “I just think this is another data point that someone needs to weigh as they're trying to figure out what the right social cost of carbon is.” Although Pizer suggests that the $220 figure might be too high, the Stanford study corroborates many scientists’ suspicions that the current $37 per ton figure used to shape emission regulations is indeed underestimated.
Another intriguing aspect of this new model, however, is that it also incorporates the economy’s ability to adapt to damage from climate changes and acknowledges that warming temperatures will economically affect high- and low-income countries differently. "There have been many studies that suggest rich and poor countries will fare very differently when dealing with future climate change effects, and we wanted to explore that," co-author Delavane Diaz said. The researchers noted that because poor countries are on average hotter than rich countries and have less rigid infrastructure, they might suffer greater economic costs due to climate change. “If temperature affects economic growth rates, society could face much larger climate damages than previously thought” Diaz said. “This would justify more stringent mitigation policy.”