Answer: There is less ice now than in the 1970s or during the Little Ice Age, but more than in 2012 or the Medieval Warm Period. It has been increasing over the last few years.
While accusing the Trump Administration of “willful ignorance” and “insensitivity” to victims of Hurricanes Harvey and Irma, manifested by denying “obvious climate change,” an article in the Sep 11 Washington Post links to a graph prepared by a Ph.D. student. This shows the extent of Arctic sea ice during the summer melt season in 2017 compared with the average in the 1980s, 1990s, and 2000s. “There is no red or blue spin on the fact that…Arctic ice is melting,” proclaims WaPo.
Records of Arctic ice date back to the mid-1700s, when sailors kept notes on Northern Hemisphere shipping lanes. Before that, we have only intermittent records assembled by the Vikings, dating back to 870 A.D., on the number of weeks per year that ice occurred along the north coast of Iceland. (Evidently, the number varied.) We have fairly accurate records only since 1953, and satellite records only since 1979.
There was less Arctic sea ice in the 2010s than in the 1950s, but there were perids of increase, with a maxium in the early 1970s and an increase between 2005 and 2007.
In 2009, Al Gore predicted that the Arctic Ocean might be nearly ice-free by 2014. Similar such predictions had been made in 1923 and 1958.
If there is less polar ice, allegedly because of human-produced greenhouse gases, it would reflect less solar heat, leading to a vicious cycle of more melting, according to the prevailing narrative.
The predicted vicious cycle, however, has not occurred. The minimum Arctic sea ice in 2016 was about the same as in 2006. In September 2016, the growth rate of the ice was the highest since measurements began in 1987. In 2017, the amount of Arctic sea ice is massively greater than in 2012.
As shown, the minimum sea ice coverage reached its lowest point in 2012, and the trend has been reversing.
Take-home Lessons:
- Sea ice extent fluctuates over time because of many natural variables.
- While sea ice has increased and decreased, atmospheric CO2 has steadily increased since the 1950s.
- It is not prudent to buy stock in a shipping company that promises early profits from the opening of an ice-free Northwest Passage.
Printable PDF of Question 2: https://goo.gl/zMjuQW