Antarctica the Green
A recently published study shows that the Antarctic Peninsula has undergone significant greening over the last four decades. This trend is set to continue, with consequences for the local ecosystem.
Satellite images speak for themselves: the Antarctic Peninsula is greening up fast. Vegetation cover has increased more than tenfold in just 40 years, from less than one square kilometer of green in 1986 to 12 square kilometers in 2021.
The greening trend has accelerated by more than 30% between 2016 and 2021 alone, with 400,000 square meters of vegetation added.
These are the conclusions of research carried out using satellite images and published in an article on October 4 in the journal Nature Geoscience. The observations made by a team of researchers from the Universities of Exeter and Hertfordshire in the UK, together with the British Antarctic Survey, confirm a widespread trend in the polar regions: the greening of these normally icy zones.
The cause, of course, is climate change, which is warming Antarctica – and in particular the Peninsula and the western part of the continent – faster than the rest of the world, notably resulting in heat waves unprecedented for the region. Added to this is increasingly frequent precipitation, which is conducive to the appearance and development of mosses.
Although, for the time being, the greening is mainly due to the presence of mosses, the fact remains that, with global warming linked to human activity, the plant world has found a gateway to a continent dominated by ice. A trend that is set to continue and even increase, notably through the formation of soil favorable to vegetation. “Soil in Antarctica is mostly poor or non-existent, but this increase in plant life will add organic matter, and facilitate soil formation – potentially paving the way for other plants to grow.”, notes Dr. Oliver T. Bartlett, co-author of the study and Senior Lecturer in Remote Sensing and Geography at the University of Hertfordshire, in a press release issued by BAS on 4 October. Mosses play an essential role in creating fertile soil on the rocky surface for other plant species, including invasive species from outside. This is a worrying finding, because while global warming is a problem for the Deep South, the introduction of species not indigenous to the continent, through tourism or even scientific activities, represents a real scourge for the fragile Antarctic ecosystem.
For scientists, the challenge now is to understand how deglaciated areas will be colonized by plants, and how this process will evolve over the coming decades. “The sensitivity of the Antarctic Peninsula’s vegetation to climate change is now clear and, under future anthropogenic warming, we could see fundamental changes to the biology and landscape of this iconic and vulnerable region,” notes Dr. Thomas P. Roland, Senior Lecturer of Physical Geography at the University of Exeter and lead author of the study, in the same release. “Our findings raise serious concerns about the environmental future of the Antarctic Peninsula, and of the continent as a whole. In order to protect Antarctica, we must understand these changes and identify precisely what is causing them.” For the process is not going to abate, far from it. Since the 1940s, 90% of glaciers on the Antarctic Peninsula have lost mass. Those most affected are particularly those on the periphery of the continent.
Of course, this phenomenon is not confined to Antarctica and its peninsula. Wherever glaciers retreat and ice melts, revealing bare rock, vegetation is likely to appear and grow. The same applies to seas and oceans, as in the Arctic, where algae proliferate as sunlight reaches water surfaces increasingly devoid of sea ice.
Even if the greening zone remains limited, and we’re not yet close to renaming Antarctica the great green continent, the problem is likely to get worse, with consequences that are still hard to pin down.
Link to the article: Roland, T.P., Bartlett, O.T., Charman, D.J. et al. Sustained greening of the Antarctic Peninsula observed from satellites. Nat. Geosci. (2024). https://doi.org/10.1038/s41561-024-01564-5
Mirjana Binggeli, Polar Journal AG
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