Daily Archives: February 27, 2013

Arctic Ice Loss

You all know that the Arctic Ice melts more each summer than ever before. In a few years, the Arctic will be ice free during the summer. The rate of annual melting is greater than expected even just a few years ago. Please note that the increasing melt of Arctic sea ice does not bode well for the associated Greenland Ice Sheet which is also showing signs of melting at a higher rate than expected. The melting of Arctic sea ice has a number of important environmental implications, but the melting of the Greenland Glacier has that plus more; it will contribute significantly to sea level rise.

Several days ago the National Environment Research Council of the UK put out some new information from the European Space Agency’s CryoSat-2 satellite program:

Arctic sea ice volume has declined by 36 per cent in the autumn and 9 per cent in the winter between 2003 and 2012, a UK-led team of scientists has discovered.

Researchers used new data from the European Space Agency’s CryoSat-2 satellite spanning 2010 to 2012, and data from NASA’s ICESat satellite from 2003 to 2008 to estimate the volume of sea ice in the Arctic.

They found that from 2003 to 2008, autumn volumes of ice averaged 11,900 km3. But from 2010 to 2012, the average volume had dropped to 7,600 km3 – a decline of 4,300 km3. The average ice volume in the winter from 2003 to 2008 was 16,300 km3, dropping to 14,800 km3 between 2010 and 2012 – a difference of 1,500 km3.

The most important thing here is the decrease in volume, which really means a decrease in thickness, of the sea ice. The ice in the Arctic partially melts every year, then refreezes. Much of the ice, in the past, never melted, and served as the base for new winter ice every year as we cycle through the seasons. But over the last few years, this “old ice” has been disappearing. This results in changes to sea temperatures, reflection of sunlight, and air temperatures which, in turn, change the nature of the northern end of the overall system of global air currents. The result of his has been a change in the relationship between more southerly air currents that are part of the process of moving heat from the equator (where the effects of the sun are stronger) towards the poles. The result of this has been a change in the nature, distribution, and typical movement patterns of cold air masses, warm air masses, and storm. Thus, extreme cold snaps in the northerly range of where people live in the Northern Hemisphere, and heat waves to the south of this, the formation of more severe northerly storm, and, apparently, the higher chance of severe North Atlantic storms slamming into highly populated areas of North America.

Here’s a video explaining one important aspect of the new findings, from Climate Nexus (Hat tip MNM)

The video is not entirely accurate. We should not forget Polar Bears! And, scientists are less hapless in their understanding of the implications of ice melt than the video suggests (see commentary above).

How Do You Get Sexual Orientation and Gender in Humans?

Humans appear to have a great deal of variation in sexual orientation, in what is often referred to as “gender” and in adult behavior generally. When convenient, people will point to “genes” as the “cause” of any particular subset of this diversity (or all of it). When convenient, people will point to “culture” as the “cause” of … whatever. The “real” story is more complicated, less clear, and very interesting. And, starting now, I promise to stop using so many “scare” quotes.

Continue reading How Do You Get Sexual Orientation and Gender in Humans?