"NOAA’s arctic report card shows stronger effects of warming in Greenland and permafrost"
The National Oceanic and Atmospheric Administration has released its annual Arctic report card with grim findings:
Temperature increases, a near-record loss of summer sea ice, and a melting of surface ice in Greenland are among some of the evidence of continued warming in the Arctic, according to an annual review of conditions in the Arctic issued today by NOAA….
One example of these changes in arctic climate is the autumn air temperatures which are at a record 5 degrees C (9 degrees F) above normal, because of the major loss of sea ice in recent years. The loss of sea ice allows more solar heating of the ocean. That warming of the air and ocean affects land and marine life, and reduces the amount of winter sea ice that lasts into the following summer. The year 2007 was the warmest on record for the Arctic, continuing a general Arctic-wide warming trend that began in the mid-1960s.
Significantly, NASA attempts to include some of this astonishing Arctic warming in its global temperature data set, whereas the UK’s Hadley Center excludes this area — a key reason NASA estimates “2005 was the warmest since records began, with 1998 and 2007 tied in second place” whereas Hadley has 1998 as the warmest year on record (see “Yes, the planet has kept warming since 1998“). The misperception that the planet stopped warming in 1998 stems more from our limited number of temperature stations in the Arctic than from any genuine trend.
The TV coverage I saw of the NOAA report (on ABC tonight) emphasized the Greenland results:
Warming has continued around Greenland in 2007, culminating in record setting (since 1970s) melt area and amplified absorption of solar radiation. Greenland’s largest glacier, among a majority of others, continued its retreat. The ice sheet lost at least 100 cubic km (24 cubic miles) of ice, making it one of the largest single contributors to global sea level rise.
But I think the tundra report is at least as significant, since we know that the rapid loss of the Arctic sea ice and the soaring Arctic temperatures is accelerating us toward the most dangerous climate threshold (see “Tundra 4: Permafrost loss linked to Arctic sea ice loss“). As a recent study found, “simulated western Arctic land warming trends during rapid sea ice loss are 3.5 times greater than secular 21st century climate-change trends. The accelerated warming signal penetrates up to 1500 km inland.”
That was a simulation. NOAA’s report card has an analysis that confirms the grim reality on the ground:
Land-based observations, while widely ranging, reflect the effects of a general warming trend. For instance, there was an increase in the relative greenness of the Arctic region, consistent with warming soil and air temperatures, earlier snow melt, and the expansion of shrubs and tree line to the north. Permafrost continues to warm… There is a continued tendency for a decrease in the snow cover of the Northern Hemisphere in the months of April through October….
Observations show a general increase in permafrost temperatures during the last several decades in Alaska, northwest Canada, Siberia, and northern Europe…. All of the [Alaskan] observatories show a substantial warming during the last 20 yr (Fig. L3). The detailed characteristic of the warming varies between locations, but is typically from 0.5° to 2°C at the depth of zero seasonal temperature variations in permafrost. These data also indicate that the increase in permafrost temperatures is not monotonic…. However, 2007 data show a noticeable increase in the temperature at 20-m depth by 0.2°C at the two northernmost sites of Deadhorse and West Dock. Permafrost temperature did not change significantly at the other North Slope sites. This may indicate a new wave of permafrost warming similar to the warming that started in 1994, which also started at the Deadhorse and West Dock sites and only later appeared at the interior sites.
Here are some temperature series from northern Alaska:
Figure L3. (top) Location of the long-term University of Alaska permafrost observatories in northern Alaska. West Dock is at Prudhoe Bay. (bottom) Changes in permafrost temperatures at 20-m depth during the last 25 to 30 yr (updated from Osterkamp 2003).
This evidence for a new wave of permafrost warming starting last year supports other evidence reported in the recent literature (see “NOAA: Atmospheric Carbon Dioxide, Methane Rise Sharply in 2007” and “Has runaway climate change begun?“).
That recent evidence suggests the Siberian permafrost may be undergoing more rapid destruction than the Alaskan permafrost, which is also supported by this temperature map from the report card’s atmospheric analysis:
Figure A2. Near surface air temperature anomaly map for October and November for recent years with a reduced sea ice cover, 2005–2007. Data are from the NCEP — NCAR reanalysis through the NOAA/Earth Systems Research Laboratory.
Clearly, the permafrost region of northern and northeastern Russia has experienced tremendous warming in the autumn over the past few years.
The time to act is yesterday.