More importantly though, the Cryosphere Today website by the University of Illinois shows that the current midwinter ice cap has not completely frozen over its coverage area. The presentation of the ice cap is color coded indicating the percentage of ice coverage in its area. The colors show that 5% and 10% of much of the ice covered area is actually open water. This means that the ice cap is susceptible to a large reduction in sea ice area when the thawing begins this March.
What does this mean? Climate deniers will say "Hey, the Arctic ice is already in the ocean, so its melting does not contribute to sea level rise", as if they discovered something important. The importance of the loss of sea ice is twofold - first, it shows undeniable evidence of global warming, and second, it reduces albedo. Albedo is the reflection of the sun's rays and energy into space. The albedo effects of polar ice caps keep the earth colder than it would be otherwise.
Since 2007, the Kara, Leptev, East Siberian, Chuchki, and Beaufort seas of the Arctic Ocean have gone ice free each summer. So, those seas are already absorbing sunlight each summer during the long days that would have been reflected to space. This will raise their temperatures. The Siberian, Kara, Leptev, and Chuchki seas overlie the siberian continental shelf. These seas are shallow, only about 150 deep or so. At the bottom lie huge deposits of methane clathrates. Methane is already be released in plumes in the Siberian Sea, and as the waters warm, these plumes will only increase in volume and extent. Another point of interest is Baffin Bay to the west of Greenland. Normally, it totally freezes over each winter.
This winter, a finger of open ocean is still there, in February, that extends far north, almost to Melville Bay. I suspect that Baffin Bay will thaw sooner than normal this spring. Since the big Arctic summer thaw of 2007, the Arctic has stayed in that pattern, and not gone back to the old pattern. Each summer, the summer sea ice has thawed to almost 3 mil sqkm. The old limit of 5 mil sqkm may have become permanent history, not to be repeated anytime soon. The trajectory is towards summers of an ice free Arctic Ocean within the next 5 to 15 years. When the Arctic is ice free in the summers, that will be a new environment for Greenland. When all the air masses coming to it go over water that is above freezing, Greenland melting should accelerate significantly.
Warmer open ocean water will release moisture to be deposited onto Greenland. This will transfer huge amounts of heat to Greenland, thus accelerating its thaw. The summer melt season in Greenland has already expanded and extended farther north. That melt season will start earlier, go longer, and get hotter. I think that much needs to be learned about the physics and process of melting ice sheets to be able to calculate how the Greenland Ice Cap will respond to this. Some say it will take 2,000 or 3,000 years to melt all of Greenland. A few say less than 500. Personally, I am not sure if it really matters.
The important thing is that our climate has become destabilized. Permafrost is melting. Methane Clathrates may be released in prodigious quantities. Trees are moving north into the tundra. Insects and birds of the temperate region are moving north into the Arctic. Tropical insects and deseases are moving into the temperate zones. Low coral islands and atolls are submerging under the sea. Lake Michigan is warm and ice free, where it used to be very cold, even in summer for swimming in Chicago. Being ice bound each winter, an ice breaker used to break a shipping a lane each spring, and the drawbridges would get stuck. It was a tradition. No longer. Chicago is my home, I know. This destabilization is taking our climate out of the pattern of the Holocene, which has been our climate for the past 12,000 years.
Now, during this time there were slightly warmer and colder times, such as the medeival "ice age". But, unless this process can be halted and reversed, then we are moving out of the Holocene climate. Can that happen? Doubtful. Most Earth Scientists blame the rise of atmospheric CO2 from 260 ppm before the industrial revolution to 390 ppm today for the observed warming. However, the rate of increase in CO2 has increased. In the 1950's, atmospheric CO2 was going up at about 0.5ppm per year. Now, it is going up at just under 3.0 ppm per year. It has taken humanity over 200 years to raise CO2 a total of 130 ppm. At the current rate, we will double it in just 40 years. And, since the rate of increase is increasing, it will likely be much less than forty years. That would put us at 520 ppm. So, if you think we have seen global warming now, just wait. By 2050, CO2 will likely be at 520 ppm. Atmospheric methane will also likely to be much higher as the permafrost thaws and the methane clathrates are released. Some say this cannot happen. But, they do not back up these assertions with any credible evidence, calculations, or viable hypotheses that explain the observations. The world governments have a hard time agreeing to managing fish stocks, or whether whales should be hunted.
Is any expectation credible that they will be able to work together to do the serious draconian measures necessary to reduce humanity's global carbon emissions to pre-industrial levels? I don't think so, either. Besides, there is the very real possibility that we have already gone past the tipping points, and that global warming is unstoppable now.
If so, the the end of the Holocene is underway. It was nice wasn't it? Not too hot. Not too cold. Just right. A real Goldilocks climate. Anybody with a suggestion for the coming new climate?
- Siberian Permafrost Carbon Release Significant But Exaggerated In News- Fifth Of Degree By 2299 At Most, Can Be Carbon Negative
- Around The Arctic June 2013
- CO2 Budget: The Lesser Known Role Of Arctic Sea Ice
- Destabilizing Arctic Methane Stores Could Intensify Climate Change
- Not As Scary As It Seems: Planet At Risk Of Heading Towards “Hothouse Earth” State