Last month saw the biggest year-over-year jump in atmospheric levels of heat-trapping carbon dioxide on record — 3.76 parts per million. And that, reports NOAA, took May 2016 to the highest monthly levels of CO2 in the air ever measured — 407.7 ppm.
At the same time, the National Snow and Ice Data Center reports the warming-driven death spiral of Arctic sea ice hit a staggering new May low (see figure). May 2016 saw Arctic sea ice extent drop “about 600,000 square kilometers (232,000 square miles) below any previous year in the 38-year satellite record.”
“We’ve never seen anything like this before,” explained NSIDC director Mark Serreze. “It’s way below the previous record, very far below it, and we’re something like almost a month ahead of where we were in 2012.”
Whether this September beats the record minimum Arctic sea ice extent set in September 2012 depends on the weather this summer, which makes predictions difficult. That said, “Persistent Arctic and sub-Arctic warmth expected to continue for months,” as Alaska Dispatch News recently reported. So we don’t see a record melt, we’re likely to come close.
The Arctic has been setting records for warmth (see my March post, “Record-Shattering February Warmth Bakes Alaska, Arctic 18°F Above Normal”). In May, key portions of the Arctic ocean were 4–5°C (7–9°F) above the 1981 to 2010 average.
Climate models have always predicted that human-caused warming would be at least twice as fast in the Arctic as in the planet as a whole thanks to Arctic Amplification — a process that includes higher temperatures melting highly reflective white ice and snow, which is replaced by the dark blue sea or dark land, both of which absorb more solar energy than ice and lead to more melting.
We know the warming will continue for decades to come since atmospheric levels of heat-trapping CO2 are also setting records, according to NOAA. This year has seen a particularly big jump because the underlying trend of CO2 rise driven by the burning of fossil fuels generally gets a boost during El Niño years.
“Carbon dioxide levels are increasing faster than they have in hundreds of thousands of years,” explains Dr. Pieter Tans, who leads NOAA’s Global Greenhouse Gas Reference Network. “It’s explosive compared to natural processes.”
Humanity is creating an explosive change in the atmosphere, which is driving an explosive change in the Arctic. Unfortunately, what happens in the Arctic does not stay in the Arctic — and the accelerated loss of Arctic sea ice drives more extreme weather in North America, while accelerating the disintegration of the Greenland ice sheet and the defrosting of the permafrost, which contains more of carbon than the atmosphere currently does.
It is time humanity stops playing with matches!