The National Oceanic and Atmospheric Administration (NOAA) has been issuing a “Report Card” noting temperatures, ice melt, biodiversity and other issues relating to the status of the Arctic since 2006. The 2016 Report Card was recently issued reflecting additional evidence of the impacts of climate change.
“Observations in 2016 showed a continuation of long-term Arctic warming trends which reveals the interdependency of physical and biological Arctic systems, contributing to a growing recognition that the Arctic is an integral part of the globe, and increasing the need for comprehensive communication of Arctic change to diverse user audiences.”
Highlights of the report include:
The average surface air temperature for the year ending September 2016 is by far the highest since 1900, and new monthly record highs were recorded for January, February, October and November 2016.
In 37 years of Greenland ice sheet observations, only one year had earlier onset of spring melting than 2016.
After only modest changes from 2013-2015, minimum sea ice extent at the end of summer 2016 tied with 2007 for the second lowest in the satellite record, which started in 1979.
The Arctic Ocean is especially prone to ocean acidification, due to water temperatures that are colder than those further south. The short Arctic food chain leaves Arctic marine ecosystems vulnerable to ocean acidification events.
Spring snow cover extent in the North American Arctic was the lowest in the satellite record, which started in 1967.
Thawing permafrost releases carbon into the atmosphere, whereas greening tundra absorbs atmospheric carbon. Overall, tundra is presently releasing net carbon into the atmosphere.”
The Executive Summary of the Report notes several factors that appear to present long term adverse impacts for the Arctic including:
“Ice on land, as represented by the Greenland Ice Sheet, saw a continuation of the overall increasing melting trend in 2016, with enhanced melt occurring in the southwest and northeast regions. The onset of surface melt ranked 2nd (after only 2012) over the 37-year period of satellite record (1979 – 2016). The duration of the melt season lasted 30-40 days longer than usual in the northeast and 15-20 days longer along the west coast, compared to the 1981-2010 average. Consistent with the spatial distribution of melt anomalies, the largest area of relatively low albedo (a measure of surface reflectivity) was located along the southwest coast, reaching down to ~20% below the 2000-2009 average….
Satellite observations of tundra greenness (a measure of vegetation productivity and strongly correlated with above-ground biomass) are available since 1982, with 2015 being the most recent year with a complete data set. Long-term trends over this period show greening on the North Slope of Alaska, in the southern Canadian tundra, and in much of the central and eastern Siberian tundra. A decreasing trend in greenness, or “browning”, is observed in western Alaska (Yukon-Kuskokwim Delta), the higher-Arctic Canadian Archipelago, and western Siberian tundra.
Warming air temperatures in the Arctic are causing normally frozen ground (permafrost) to thaw. The permafrost is carbon rich and, when it thaws, is a source of the greenhouse gases carbon dioxide and methane. Northern permafrost zone soils contain 1330-1580 billion tons organic carbon, about twice as much as currently contained in the atmosphere. Tundra ecosystems are taking up increasingly more carbon during the growing season over the past several decades, but this has been offset by increasing carbon loss during the winter. Overall, tundra appears to be releasing net carbon to the atmosphere.”