Arctic Greening

Arctic Greening Photo credit: Ramakrishna Nemani of NASA’s Ames Research Center and Sangram Ganguly of the Bay Area Environmental Research Institute and NASA Ames [Public domain], via Wikimedia Commons

30 years of satellite data confirms that the Arctic is greening.


A greener Arctic. I’m Bob Hirshon and this is Science Update.

Climate change is warming the Arctic. Now, researchers confirm that the increased temperatures are bringing vegetation to areas once covered in snow. UC Berkeley scientist Trevor Keenan and his team analyzed 30 years of satellite images from the coldest parts of the Northern Hemisphere. He says the massive greening they documented can disrupt every level of the food chain.

If you change the landscape you change everything else in an ecosystem that depends on the vegetation that’s there. So it’s a massive perturbation to ecosystems in quite a very short amount of time and that doesn’t give time to a lot of the components of those ecosystems that have evolved to live there to catch up.

The researchers write in the journal Nature Climate Change that the new vegetation also absorbs more light from the sun, leading to even further warming. I’m Bob Hirshon, for AAAS, the science society.

Making Sense of the Research

Most of us think of the Arctic as a place covered in ice and snow. In fact, the icy, snowy regions of the Arctic have captured people's imaginations for centuries. It covers a region at the extreme north of the earth and includes the Arctic Ocean (the world’s smallest ocean) and the surrounding seas, as well as the world’s largest island, Greenland, and the northern extremities of Alaska and several countries, including Russia and Canada.

While much of the Arctic Ocean is covered in floating sea ice, permanent land ice only covers a small area outside of Greenland. The climate of the Arctic is highly variable, both with season and location. For example, in some areas of the northern Arctic, temperatures can reach -76 degrees Fahrenheit (-60 degrees Celsius) in the winter while temperatures in the summer can be 69 degrees Fahrenheit (20 degrees Celsius). In addition, the region isn't just covered in ice and snow. The typical habitat is actually tundra, which is characterized by treeless, grassy plains. And a characteristic feature of Arctic tundra is permafrost, which is permanently frozen ground.

The cold temperatures of the tundra have severely limited plant growth in the past and only certain types of vegetation, like sedges, grasses, shrubs, and some low-growing trees, have historically been able to survive in the region.

All of that could change, though, if warming trends in the region continue. According the research being conducted by Dr. Keenan and his colleagues, warming temperatures in the Arctic region have contributed to the expansion of plant growth in that area—and in other cold regions like Alaska and the Tibetan Plateau. Data collected by the Advanced Very High Resolution Radiometer on board a succession of satellites operated by the National Oceanic and Atmospheric Administration over the past 30 years show that the areas across the globe where cold temperatures limit plant growth have declined by 16 percent. By 2100, they could shrink by an estimated 80 percent. So, by 2100, only 20 percent of the vegetated land in the northern hemisphere will be limited by cold temperatures, allowing plants to grow earlier in the season and in new and unexpected places.

This situation could bring about positive changes, like more carbon uptake and more biomass production, but it also could bring about some negative ones, like a disruption to the delicate balance in cold ecosystems with the introduction of new species to the region that would compete with the vegetation that is traditionally found there.

Now try and answer these questions:

  1. Where is the Arctic region located? What countries, states, and geographic areas are located in the Arctic?
  2. What is permafrost?
  3. What has been happening to the vegetation in the region as a result of the warming trends?
  4. What instruments did scientists use to collect the data?
  5. Scientists predict that this warming trend will continue. What might be some positive outcomes of this trend? What might some negative outcomes be?

To learn more about how climate change is affecting plants, you can listen to Thoreau's Plants.

Ascending Plants is another Science Update that looks at how some plants are moving to higher latitudes as a result of climate change.

Going Further

For Educators

You could use this Science Update along with some of our other Science NetLinks resources to help your students learn about climate change and the various effects it is having on our planet. This Science Update could be a good addition to our Grasslands and Climate Change (6-8) lesson or our Simulating Climate Change Research in Grasslands (9-12) lesson.

For more ideas, check out the resources listed here:

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