Laura Nielsen for Frontier Scientists –
“The Arctic is not like Vegas. What happens in the Arctic doesn’t stay in the Arctic. The major changes that we see in reduction in sea ice, reduction in spring snow cover extent, increasing vegetation that changes the radiation balance of the surface, potential changes in greenhouse gas fluxes, those are all ...implications that extend beyond just the Arctic region to the rest of the world."
Howard E. Epstein, environmental professor at the University of Virginia, was among the panel of researchers who presented the National Oceanic and Atmospheric Administration's 2013 Arctic Report Card at the annual American Geophysical Union conference in San Francisco.
The NOAA Arctic Research Program releases the Arctic Report Card to summarize changing conditions in the Arctic, an increasingly important region in the world stage. One hundred forty-seven scientists from 14 countries contributed to this year's peer-reviewed report. 2013's release marks the Arctic Report Card's 7th annual update.
Weather in Alaska
University of Alaska Fairbanks geophysicist Martin Jeffries, part of the U.S. Arctic Research Commission and principal editor of the report, spoke about the unusual weather in Alaska during 2013. Spring air temperatures were frigid: in central Alaska, residents experienced the coldest April in 90 years. The cold spring contrasted with unusually warm air temperatures measured across Eurasia (Europe & Asia), where in May 2013 Arctic regions reached a new record low snow extent.
Back in cold Alaska, it wasn't until the 26th of May that the first green shoots started appearing on birch and aspen trees. That's the latest date since records began in 1972. After the slow start, though, temperatures really warmed up: Alaska experienced its second-warmest summer on record, and Fairbanks recorded 36 consecutive days with temperatures at or above 80°F (~26.7°C).
"There were fewer extreme snow and ice events in 2013 compared to 2012 but the impacts of a persistent decades-long warming trend remain clearly evident," Martin Jeffries explained. "We can't expect to be smashing records every year —there are going to be ups and downs— but those ups and downs are going to be superimposed on, nevertheless, a trend to a warmer Arctic and its effects throughout the Arctic environmental system."
Vegetation and wildfire
We know that warmer temperatures and earlier snow cover decline are making the Arctic greener. The growing season has increased by an average of over 9 days per decade since observations began in 1982, and tundra vegetation productivity has increased by 25%. This North American 'greening' has accelerated since 2005. When scientists examine a census of Arctic plant life, they note tall shrubs expanding their range north. The hotter summers, longer growing seasons, and increase in biomass (plant matter) that results from larger plants invading the tundra can create an environment ripe for wildfires. According to Howard E. Epstein, Alaska's North Slope has seen a substantial increase in the number and severity of tundra fires.
Tundra fires, like the 2007 Anaktuvuk River fire, release greenhouse gasses and push dark soot called black carbon into the atmosphere. The Anaktuvuk River fire burned 401 square miles [1,039 square kilometers] and released approximately 2.1 million metric tons [2.1 teragrams] of carbon, about the same amount of greenhouse gasses that the city of Miami releases in a full year. That's because the fire thawed and burned layers of soil called permafrost which usually remain frozen underground. Permafrost contains ancient plant matter which releases carbon dioxide and methane when it is decomposed (a process sparked by above-freezing temperatures) or burned. For all the carbon the Anaktuvuk River fire released, its flames only reached layers of permafrost containing plant matter 50 years old; deeper permafrost layers across the Arctic hold deep reserves of far older specimens.
Weaker sea ice
Don Perovich, Thayer School of Engineering at Dartmouth College, was on hand to talk about Arctic sea ice. "There was more sea ice at the end of summer of 2013 than there was at the end of summer the record breaking year of 2012, but the 2013 minimum ice extent was still 18% below the average minimum and ranked as the 6th smallest ice extent since satellite observation begain in 1979. Moreover, the past 7 years have had the 7 smallest ice extents in the observatinal record," (2007-2013). He added that the 'new normal' of reduced Arctic sea ice means a continuing shift from older thicker ice to younger thinner ice, as less ice survives the summer melt and sea ice reforming in late autumn is more often delayed because of heightened sea surface temperatures.
Because of warmer ocean temperatures, NOAA's data reports that the Arctic Ocean and adjacent waters are becoming more hospitable to species from lower lattitudes. We're seeing fish that normally range in more southerly waters, just as on land plant species are creeping northward.
The Arctic in the wider world
Increasing temperatures are strongly impacting the Arctic, which is warming faster on average than any other region of the world. It is experiencing the consequences of global warming. Those heightened temperatures are making snow and ice retreat. The dark land cover that is revealed: dark open ocean waters, dark soil over permafrost, black carbon from air pollution, even the leaves on tall shrubs, are friendly surfaces for solar radiation. When sunlight hits bright white snow and ice it bounces away, back into space. When it encounters a dark surface it soaks in instead, keeping the Sun's heat in Earth's atmosphere. This is part of Arctic amplification: higher world temperatures set off a chain reaction of events that alter the solar radiation balance in the Arctic, causing a positive-feed-back-loop of warming.
Less ice-covered Arctic ocean water is warmer because of the sunlight it's absorbed, but every fall the ocean's heat is transferred back into the atmosphere. That upset in the atmospheric norm has the potential to alter the jet stream and impact weather across the Northern Hemisphere, and perhaps beyond.
We need to remember that the world is connected. NOAA's Arctic Report Card may talk about a region that is far from you, but the Arctic is not isolated. Changes there have implications in the broader world. The consequences of anthropogenic (human-caused) global warming include more extreme weather, and force changes on our planet that have real economic impacts on people and their livelihoods, as well as vastly altering natural habitats. We are living in a changing world... we are changing that world.
Martin Jeffries: "The impacts of the warming climate on the physical environment are influencing Arctic ecosystems on the land and in the sea, and multiple observations provide strong evidence of widespread sustained changes that are driving the Arctic environmental system into a new state. Some would say that this has already happened." He adds that in this new paradigm we should continue to expect regional variability and "Expect to see continued widespread and sustained changes throughout the Arctic environmental system."
Frontier Scientists: presenting scientific discovery in the Arctic and beyond
Delve deeper into the Arctic Report Card 2013:
Vistit NOAA's page Arctic Report Card: Update for 2013, tracking recent environmental changes
Check out the 2013 Arctic Report Card: Visual Highlights on Climate.gov
Watch a short video presenting 2013 Arctic Report Card data by NOAA
Investigate the long Arctic Report Card 2013 AGU Press Conference from the 2013 Fall Meeting