President Barack Obama is going to spend three days this week personally inspecting the ravages of man-made climate change in the Land of the Midnight Sun. The President is seeking to burnish his climate change policy legacy. As Whitehouse.gov explains:
President Obama is traveling through Alaska to shine a spotlight on the impacts of climate change, one of the biggest threats we face … it is being driven by human activity, and it is disrupting Americans' lives right now.
Most climate researchers do report that average temperartures in Alaska and the Arctic more generally have been rising over the past several decades. For example, a 2014 study by York University physicist W. A. van Wijngaarden looked at the temperature records for 118 weather stations around the Arctic and reported:
For the period 1820–2014, trends were found for the January, July and annual temperatures of 1.0, 0.0 and 0.7 °C per century, respectively. Decadal variations are evident and much of the temperature increase occurred during the 1990s. Over the past century, Siberia, Alaska and Western Canada have experienced somewhat greater warming than Eastern Canada, Greenland and Northern Europe.
In aonther 2014 study, Wijngaarden analyzed the temperature data for 27 weather stations in the Canadian arctic and also found a warming trend for the period 1895–2014:
Trends were found for the January, July and annual temperatures of 3.1, 1.6 and 1.9 °C per century, respectively. Similar trends were found in the western and eastern Arctic. The warming occurred primarily in the first and last decades of the twentieth century. For the period 1915–1995, the annual temperature trend was only 0.4 °C per century.
Specifically with regard to temperature trends in Alaska, a 2014 study found that temperatures fluctuated hot and cold in phase with shifting sea water temperatures in the northern Pacific Ocean (the Pacific Decadal Oscillation). Still that study reported:
There has been a gradual upward trend of Alaskan temperatures relative to the PDO since 1920, resulting in a statewide average warming of about 1°C.
In addition, since satellite-monitoring of Arctic sea ice began in the 1970s, there has been a downward trend in its extent. The National Snow and Ice Data Center is reporting:
On August 16, 2015 sea ice extent stood at 5.79 million square kilometers (2.24 million square miles). This is 1.35 million square kilometers (521,200 square miles) below the 1981 to 2010 average, and 1.17 million square kilometers (451,700 square miles) above the level for the same date in 2012, the year of the record low extent.
NSIDC
Interestingly, temperatures in Alaska had been trending downward during the first decade of this century. Why? Because the PDO has shifted to a cooler phase. Nevertheless, temperatures on the North Slope that are affected by the general warming of the Arctic Ocean remained +1.5 degrees Celsius higher than the long-term average for that weather station. See map:
Wendler
More recently, Alaskan temperatures have again increased with the Last Frontier experiencing its second warmest year to date.
