Scientist say that this series of events affects tundra vegetation

Apr 11, 2012 14:53 GMT  ·  By

The fact that our planet's climate is changing, and that we are responsible is no longer a secret to anyone. In studies conducted in the Arctic, scientists determined that this phenomenon is leading to an increase in tundra vegetation, and established that this can promote global warming.

In other words, the warmer the climate gets, the more tundra-specific vegetation developed at high latitudes. While this process may seem harmless – plants take up carbon dioxide from the atmosphere, after all – the bad part is that tundra vegetation is very dark.

This contributes to decreasing the albedo of northern polar regions, allowing this part of the planet to reflect a lot less heat into space than it used to. More heat is therefore absorbed into the ground, promoting even more ice and permafrost melting.

The investigation that confirmed the existence of this vicious circle was conducted by scientists at the Finnish Meteorological Institute (FMI). They used satellite observations to extract long-term trends on the link between terrestrial albedo and snowmelt.

The data they selected spanned 16 years, and covered periods between March and June of each year. This is when the Northern Hemisphere summer is causing the most significant melting in the Arctic.

“The study revealed that vegetation was thicker in Norway. With the exception of the differences in vegetation, the other prevailing conditions, such as temperature, precipitation and solar radiation, were almost the same in both countries,” FMI investigator Juval Cohen explains.

“The difference in the melting of snow between Finland and Norway affects the albedo on land. During the snowmelt period, the albedo was almost always higher in Finland,” the expert goes on to say.

Climate scientists agree that global warming has been changing the average Arctic snowmelt rates for more than 10 years. Its effects are starting to become increasingly obvious and severe, they add.

Changing the albedo of Arctic areas leads to modifications in the delicate, Earth-wide balance between how much solar radiation is absorbed by the planet and how much is reflected back into space. This balance does not even take into account the greenhouse effect that is also accelerating global warming.

“In April and May in Norway, an area of 100 x 100 kilometers absorbs about 100 000 terajoules more solar radiation than a corresponding area in Finland. This is enough energy to melt an ice cube roughly 330 x 1 000 x 1 000 meters in size,” the FMI investigators conclude, quoted by PhysOrg.