Your Editorial, ‘Climate lag will catch up with us’ (Market News, June 17), worries that people and governments don’t appreciate the full consequences of their carbon dioxide emissions because these won’t be known for another 40 years. But in the Arctic, where temperatures are rising twice as fast as elsewhere on the planet, these consequences are already evident.
In Greenland, the huge Illulissat Glacier, covering about 42,000 square miles, is shedding ice into the ocean at a rate of over 150 feet per day. Between 2000 and 2010 it retreated nine miles — farther than it had retreated in the previous 100 years. Melting glaciers result in rising sea levels that will displace millions of people.
Also evident in the Arctic are feedback processes that are unleashing huge amounts of warming. Three examples:
1) Melting Arctic ice exposes darker water and land surfaces that absorb more of the sun’s energy. This warms the surface further, causing faster melting, which then causes more warming, and so on, creating a self-reinforcing cycle by which global warming feeds on itself, amplifying and accelerating the warming trend.
2) Warmer temperatures are melting Arctic permafrost soils that have accumulated vast stores of organic carbon, releasing carbon dioxide, and also methane which is 23 times more potent a climate change driver than carbon dioxide. Warming further increases these releases, creating a feedback loop.
3) Warmer temperatures are also thawing methane hydrates, found on the seabed or deep underground in the Arctic. Recent reports indicate that methane is leaking from the ocean floor, while in Siberia, huge craters have appeared that scientists believe are caused by explosions of methane released by underground melting.
Once these feedback processes start generating more greenhouse gases than we humans do by burning fossil fuels, climate change will be unstoppable. That’s why we need strong action on climate change right now.
Anne Morris