Vegetation plays a major role in Arctic warming

For the first time, an international team of scientists has documented the central role that vegetation plays in Arctic warming. 

The Arctic is warming three times faster than the global average. Where snow and ice once reflected sunlight back into the atmosphere, melted terrain now absorbs heat into Earth’s surface. There has long been speculation about how vegetation emerging from melting snow affects the warming of Arctic climates.

Using data measured at 64 Arctic sites from 1994-2021, the team documented the great importance of vegetation for Arctic warming.  

“Theoretically, it has long been understood that surface vegetation helps heat an area as plants absorb solar radiation. In our new study, we confirm this theory through actual measurements and demonstrate a correlation between the amount of energy absorbed on the surface and the types of vegetation found there,” said Professor Thomas Friborg of the University of Copenhagen.

For more than 20 years, Friborg has measured climate data from northern Sweden, northern Russia, and Greenland, and this data was used for the study.  

The researchers compared fifteen factors that affect the “surface energy budget” (SEB), which describes how solar energy is converted when it hits Earth’s surface. They analyzed how Arctic areas such as barren tundra, peat bogs, shrub-covered tundra and wetlands influence how solar energy is converted.

The results showed that some of the greatest differences in energy conversion are found between dry areas with little vegetation, like grasses, and wet areas such as peat bogs that are rich in moss and small trees. Dry soil surfaces produce greater warming, as the energy from wet areas is converted into evaporation.

“Our study shows that the type of vegetation on an Arctic surface has a major impact on how direct warming will be. Whether there are shrubs, grasses, mosses or wetlands matters considerably for the degree to which solar energy is absorbed and how it gets converted. In fact, in some cases, vegetation type is nearly as decisive as whether snow is present,” explained Professor Friborg.

The Arctic region is greening as temperatures rise, and knowing how vegetation affects warming is crucial for climate predictions. By demonstrating how Arctic plants convert solar energy, these results could influence how climatic changes are predicted on a global scale. 

“In many ways, the Arctic is the canary in the coal mine – it is where we first and most powerfully see global warming. But at the same time, it is incredibly complex to predict. We are currently witnessing warming of 3-4 degrees, which is higher than quite a few of the models predicted 20 years ago. As such, there is a constant need to refine models and include as much data as possible in them,” concluded Thomas Friborg.

The study is published in the journal Nature Communications. 

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By Katherine Bucko, Earth.com Staff Writer

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