When we talk about mitigating the effects of climate change — many of which at this point cannot be stopped — we tend to focus on steps we can take to reduce further increases to the amount of carbon dioxide released into the earth’s atmosphere. The much-debated Green New Deal (GND) proposes a low-carbon electricity grid and a net-zero-emissions transportation system that would cost an estimated $8.1 trillion over the next 10 years. Including all its goals (guaranteed jobs, universal health care, food security, green housing), the price tag on the GND is around $93 trillion over the next decade.
Even if, by some miracle, the GND’s climate change goals were to be adopted, the impact on global change might be negligible. That’s due to melting permafrost and a significant drop in the snow and ice packs that blanket the earth’s Arctic region. These effects already have begun and won’t be stopped, although they might be slowed by human intervention.
In a new study published Tuesday in Nature Communications, researchers have calculated the economic effect of melting permafrost and disappearing snow and ice in the Arctic under a number of scenarios. The mean economic impact of more warming reaches a peak at an economic cost of nearly $70 trillion by the year 2300. That works out to global economic damage of $250 billion annually for 280 years.
One obvious question is, “Why 280 years?” One answer is because the world’s oceans will continue to rise until 2300 even if net-zero greenhouse gas emissions are sustained for 280 years. So what? According to research reported in February 2018, each five-year delay beyond 2050 in reducing carbon emissions to zero risks another one meter (39 inches) rise in sea level by 2300.
Another obvious question is how much impact does $810 billion a year for 10 years have on an annual cost of $250 billion over 280 years. Over the full 280 year timeline, $8.1 trillion averages about $29 billion a year. If the point of no return on global warming is just 12 years away, committing $29 billion a year is not an option. It’s the full $810 billion or nothing.
The researchers looked at the carbon released into the atmosphere due to the melting permafrost and at how the loss of land snow and sea ice cover is increasing the absorption of solar energy at high altitudes. These effects “amplify the anthropogenic signal” created by human-caused pollution and are three of the primary tipping elements that have been identified in the earth’s climate system. The following illustration from the National Academy of Sciences indicates the level of temperature change at which different tipping elements are at risk of cascading like toppling dominoes that further raise temperatures.
Human-caused climate warming could rise by three degrees Celsius by the end of this century. If that happens, carbon emissions from the melting permafrost will rise from an annual total of around 10 billion metric tons currently to an estimated 280 billion metric tons of carbon dioxide and 3 billion metric tons of methane in 2100. Methane’s potency as a greenhouse gas is as much as 20 times higher than carbon dioxide’s. But several important accomplishments in climate science may help the environment.
One final note: there have been studies that tried to estimate the positive economic effects due to melting sea ice in the Arctic. The so-called Northern Passage through the waters north of Russia and Canada would shorten the trip that ships now make from the east coast of China to Europe. Less sea ice also opens up oil, gas and mineral extraction in those far-northern waters. The positive economic impact is outweighed by the negative impact by a factor of 10.