Arctic Science Explained: The Arctic Report Card
March 2, 2022
By Liz Weinberg
By Katherine Schexneider
Welcome to Arctic Science Explained! Each month, Collaborations community member Katherine Schexneider breaks down a topic related to Arctic science. If you have a topic you’d like to see featured, please email email@example.com. This month, Katherine explains some of the important points of the Arctic Report Card.
Early in January, my friend Wilson told me about his New Year’s resolution to learn more about climate change and asked for a book recommendation. He knows I do volunteer work on climate change in the Arctic, so he was ready for something involving snow and ice. I suggested he read the Arctic Report Card 2021 and showed him how to download it from the website. This annual report, published in December for sixteen years now, summarizes the status of seven climate parameters, such as air temperature and sea ice, and also offers several brief essays on current topics of interest in the circumpolar north.
A little leery of something not on the New York Times best sellers list, but excited about all the cool-looking graphics, he dove right in to the Arctic Report Card. A couple of weeks later, we met for lunch, and he brought his dog-eared and marked-up copy to discuss his questions and thoughts. They brought to the fore several really important points the educated lay person should probably know about the Arctic Report Card, so I am sharing them here.
The Arctic Report Card highlights dramatic changes underway in the region. Image:
It’s a report card but there aren’t any grades. Why not?
Anomalies are the new grades. The problem with grades is that they give us an absolute measure of something: a 78 is a C+, 92 is an A-, and so on. We want a measure of change because the climate is changing, and we want to know by how much.
If I told you the average sea surface temperatures of the Kara and Laptev seas were ~3.3°C in 2021, that wouldn’t tell you much, but if I said it was ~1.0-3.5°C higher than the average temperature over a three-decade period (1982-2010), that would mean something. You’d understand the Kara and Laptev seas are warming, by a significant amount. And although 2021 is just one data point, the 1982-2010 reference period lets us compare 2021 to the recent climate of this region (remember that in this case, climate is defined as three decades worth of data in a region). And once we start laying out several data points (years of sea surface temperature, for example), we can see that 2021 wasn’t the only anomalous year. So were 2020, 2019, and so on.
To sum up, anomalies tell us how different a data point is from an established average.
This graphic from the Arctic Report Card 2021 shows annual temperature (October 1, 2020–September 30, 2021) across the Arctic compared to the 1981-2020 average. Deep reds across the Eurasian Arctic over the Laptev Sea show the imprint of a record-warm fall. Image: , based on ERA5 Reanalysis data from the Copernicus Climate Change website
Complexity is a recurring theme. I guess it’s kind of a domino effect when one thing changes and that causes a change in something else, and so on. Right?
You’re on the right track, but the domino metaphor is linear, and that’s too simplistic. Those domino videos are pretty cool, but they show us one domino hitting the next, then the next and the next, in one smooth line. The Arctic is an ecosystem, a huge complex web of everything from inorganic elements, like carbon and mercury, to bacteria, microscopic animals like zooplankton, larger animals (up to the polar bear, of course), plants everywhere from the sea to land, water in its various forms, gases, human-made structures like roads and buildings, and human beings.
As one example, ocean acidification makes it harder for zooplankton to survive, but not algae (such as phytoplankton and seaweeds) so much. This in turn impacts juvenile survival of the sea snail and impacts Arctic cod population. These changes make it harder for large animals that Arctic peoples depend on, like walruses, to find food and survive; they impact the economic well-being of fishing communities; and more. There isn’t one line of dominos, but thousands mixed together, affecting one another in countless ways.
Why does it matter whether you have snow on ice or not in the Arctic Ocean? How important is this albedo effect concept?
It’s super important. When you understand the albedo effect you can quickly grasp how the Arctic is warming, and why it’s heating up two to three times faster than the planet as a whole. Light from the sun, called solar radiation, travels to Earth, where some of it is absorbed to cause warmth, and some of it is reflected and prevents the planet from becoming too warm. The greater the percentage of reflected solar radiation, the higher the albedo measurement.
We know that light colors reflect radiation better than dark ones. We avoid stepping on black asphalt barefoot on a hot summer day because we know it absorbs more heat than, say, a light gray sidewalk. Now, snow-covered ice is white, and ice free of snow cover is gray and darker, so snow reflects sunlight more than the darker bare ice does. The more bare ice there is, the more heat is absorbed and the warmer it gets. Also, open ocean is blue-green and absorbs more solar radiation.
This graphic from the Arctic Report Card 2021 highlights changes in tundra greenness between 2000 and 2021, based on satellite observations. Arctic-wide, most areas are greening—a sign of increasing plant productivity in a warmer climate. A few areas are browning, which points to competing local influences, including extreme events like fires. Image: , based on data from Matt Macander
Why isn’t the greening of the Arctic a good thing? Green plants remove carbon dioxide from the atmosphere.
True, but the complexity of the Arctic ecosystem means that there’s a lot more going on besides carbon dioxide removal. Greening of the Arctic refers to the colonization of tundra by larger trees and shrubs, replacing the low-lying growth that characterizes this region. There are effects on “biodiversity, surface energy balance, permafrost temperatures, and biogeochemical cycling” (Arctic Report Card 2021, p.62). Yes, it looks like the increasing amount of plants are absorbing more carbon dioxide, but that’s not the only factor at play. For example, permafrost contains twice as much carbon dioxide as the atmosphere does, and thawing will lead to its release.
So, what we see is an increase in taller shrubs and some woody plants in the Arctic tundra, a region defined by an absence of trees and low shrubs, and we need to ask, as we do with everything we observe in the Arctic, “Ok, but what else is going on?”