Climate change is warming the northernmost latitudes of our planet at an alarming rate, and this is increasing plant growth in areas that were previously snowy tundra. The arctic tundra is a vast treeless ecosystem where the subsoil is permanently frozen. Tundras cover large Arctic ranges in Europe, Asia, and North America where frozen soil acts as a crucial carbon store. Rising global temperatures and increasing vegetation could trigger the release of these stocks, further exacerbating planetary warming. Research is vital for measuring the increased greenness of the arctic region to understand the complex interactions that underpin this expansion of vegetation.
Researchers from 40 institutions, including the University of Sheffield, have been experimenting with how to implement the newest drone and satellite technologies to understand arctic greening. These technologies allow a higher-resolution view over a large and threatened area of our planet. Our understanding of these events is increasingly vital for mitigating the effects of climate change. Dr Isla Myers-Smith, of the University of Edinburgh’s School of GeoSciences, said: “New technologies including sensors on drones, planes and satellites, are enabling scientists to track emerging patterns of greening found within satellite pixels that cover the size of football fields.”
The results from these experiments highlight the complexity of the underlying mechanisms of arctic greening. The impact of rising arctic temperatures combines with other factors such as elevated carbon dioxide, snowmelt, and wetness of landscapes. Loss of snow cover reduces the amount of the Sun’s radiation that is reflected away from the planet. Due to warming temperatures, the growing season is lengthening, as winters become milder. There are even reports of ‘lost winters’ due to the increasing timidity of recent winter weather. In contrast with this, extreme weather events such as storms, floods, and freeze-thaw, are becoming more frequent. These effects can lead to the release of carbon balancing out or even exceeding the amount taken in by plant growth and therefore exacerbating global warming.
Co-author Gareth Phoenix, Professor of Plant and Global Change Ecology at the University of Sheffield, said: “The greening of the Arctic has been one of the clearest consequences of climate change we can see in the natural world.”
The MET office predicts global temperatures in 2020 will average 1.1 degrees Celsius higher than preindustrial levels. This is highly concerning because of how quickly we are closing in on the 1.5 degrees Celsius limit set in the Paris Agreement that is key to preventing irreversible damage. This research into arctic greening could aid us in maintaining the balance between the amount of carbon captured and carbon released into the atmosphere in these regions.
Featured image: Jeffrey T. Kerby, PhD, launching a camera drone in Qikiqtaruk, Canada. Photo: Dr Isla Myers-Smith