Our World is Melting Where In the Recent Past We Had Greater Certainty of Climate Conditions

June 20, 2019 – If you haven’t been paying attention of late, “there’s a whole lot of melting going on” to parody an old Elvis Presley song. The latest news from the Canadian Arctic and Alaska is the permafrost is thawing for more rapidly than any climate models had predicted. Then there is the news about Himalaya’s alpine glaciers which are showing a rapid decline since the 1970s based on comparing satellite day today with images captured earlier. And from East Antarctica, the coldest place on Planet Earth, continental glaciers and ice shelves are showing instability where climate scientists thought we wouldn’t see any changes for multiple decades into the future.

The Melting Permafrost Problem

The permafrost melt is being described as twice the anticipated climate change problem in an April 30, 2019 report appearing the in Nature: International Journal of Science. Although published two months ago it is only in the last few days that the press has picked up on this information.

How much of the permafrost is melting at rates more rapid than predictions? About 20% creating unstable land surfaces, massive erosion, and landslides, and flooding that topples homes, forests, and buckles all-weather surface roads. For the First Nations, and Inuit people of Canada’s North and Alaska, the instability is a threat to hunters and trappers, the traditional livelihoods for many. Kettle lakes that dot the Northern permafrost are vanishing overnight seeing the water within them suddenly diverted.

The most unstable areas of permafrost contain 90% ice which makes them extremely sensitive to warming. These areas cover a million square kilometers of Canada, Alaska, and Siberia, and contain 130 billion tons of organic carbon. That number equals 10 years of human greenhouse-gas emissions. If 20% of the 130 billion tons are released into the atmosphere it will be methane (CH4) which has an estimated half-life of seven years with a higher global heating potential than carbon dioxide (CO2) by a factor of 28:1. And then when CH4 oxidizes it breaks down into CO2 and water vapour. So even then it continues to contribute to global heating since these latter two are both greenhouse gases.

U.S. Spy Satellites Reveal Melting Himalaya Glaciers

In the 1970s a U.S. spy satellite, Hexagon KH-9, surveyed over 2.2 billion square kilometers (877 million square miles) of the Earth’s surface capturing millions of images. Many of the pictures show the state of the Earth’s “third pole.” Next to Antarctica, and Greenland, the Himalaya glaciers are the largest body of permanently frozen freshwater on Earth and the source of Asia’s greatest rivers from the Indus to the Ganges, the Brahmaputra to the Irrawaddy, Salween and Mekong, and finally to the Huang He (Yellow) and Yangtze. Billions rely on these waterways for freshwater, food, and transport.

In the June 19, 2019 issue of the journal Science Advances, researchers compared Hexagon KH-9 imagery with current satellite views of Himalayan glaciers  and observed over the last forty years significant ice loss, “with the average rate of ice loss twice as rapid in the 21st century compared to the end of the 20th century.” The results suggest the observed acceleration can be explained by average warming as recorded by meteorological monitoring within the area by between 0.4 and 1.4 Celsius (0.72 to 2.52 Fahrenheit) from 2000 to 2016.

Is warming the only explanation for the ice loss? The researchers compared changes in European glaciers in the Alps and observed similar accelerated ice loss. In the Alps, an abrupt warming trend began in the mid-1980s, whereas the Himalayas warming was more gradual at that point before accelerating in the mid-1990s. Both alpine areas today are showing accelerated ice loss rates consistent with the warmer temperatures that have been observed since the turn of the 21st century.

How much water have the Himalaya glaciers lost in the last 40 years? About 8 billion tons or enough to fill 3.2 million Olympic-sized swimming pools.

East Antarctica’s Melting Poses the Biggest Sea Level Change Problem

This cold place sees temperatures on average of -55 Celsius (-67 Fahrenheit). The ice is 5 kilometers (3 miles) thick in many areas. It’s been around for more than 10 million years. But lately, this picture of stability is changing. The glaciers of East Antarctica are starting to move at a quickening pace with bergs breaking off into the Southern Ocean at an increasing rate. One glacier alone, the Totten, contains enough ice to raise global sea levels 3.8 meters (12.6 feet).

Satellite imagery shows the edges of East Antarctica, the ice that forms shelves above the Southern Ocean, eroding more rapidly. And as these edges erode and calve large icebergs, the ice fields behind them become destabilized and begin to accelerate downward.

What is causing this acceleration? If you read yesterday’s posting from this site you can begin to understand the mechanism at work here. Increased atmospheric turbulence in winds over the Southern Ocean because of atmospheric heating is shaking up the Southern Ocean and injecting warming into its depths. And even though these ocean waters would seem frigid to us, they are considerably warmer than in the past. In fact, Southern Ocean temperatures adjacent to Antarctica are currently between 3 and 4 Celsius (37.4 to 39.2 Fahrenheit) degrees, and in Antarctica that is hot, enough to cause significant melting.

East Antarctica represents the largest expanse of continental glaciation today. Its ice sits both above and below sea level because the mass is so heavy it has caused a number of bowl-shaped depressions whose surfaces are well below sea level. Incursions of ocean water can make their way inland and destabilize the ice. That could explain why the Totten Glacier is flowing more rapidly than at any time since it was first observed. It is joined by four other smaller glaciers nearby that are moving even faster than Totten. And another glacier, the Denman is also speeding up by 16% since the 1970s. Faster moving glaciers are a strong indicator of a hotter world.

In a recently published study appearing in the Proceedings of the National Academy of Sciences (PNAS), researchers published a four-decade study using satellite-gathered data and atmospheric climate models which show that the hotter world is indeed with us producing results similar to that which we have described for the Himalayas.

The increase in ice mass loss in East Antarctica is today eight times greater than observations made between 1979 and 1990. That melting has been raising sea levels by an average of 3.6 millimeters (plus or minus 0.5 millimeters) or 0.14 inches per decade. Alone, these numbers are not the kind to equate with coastal city submergence threats, but the trend is one of acceleration which suggests that 3.6 millimeters could soon become 14 millimeters or better than a half inch per decade by mid-century. And that’s just the ice melting from East Antarctica’s ice shelves and coastal glaciers. West Antarctica which has been melting faster is not included in this equation as is not melting from Greenland, Scandinavia, and Canada’s North.