Satellite data indicates recent Arctic peatland expansion with warming.

Area of Science:

• Ecology
• Climate Science
• Remote Sensing

Background:

• Northern peatlands are crucial carbon stores.
• Arctic warming is significant, with temperatures rising by ~3°C in recent decades.
• The impact of warming on peatland extent remains unclear.

Purpose of the Study:

• To determine if Arctic peatlands have expanded laterally over the past 40 years.
• To assess the relationship between climate warming and peatland growth.
• To evaluate the role of expanding peatlands as carbon sinks.

Main Methods:

• Analysis of long time-series Landsat satellite data.
• Fieldwork in situ across 21 transects in the European and Canadian Arctic.
• Assessment of Normalized Difference Vegetation Index (NDVI) and Normalized Difference Moisture Index (NDMI) trends.

Main Results:

• Over two-thirds of studied peatland edges showed significant greening in the last 15-20 years.
• Peak summer moisture levels remained stable or increased at most sites.
• Evidence suggests lateral expansion of Arctic peatlands over the last 40 years.

Conclusions:

• Arctic peatlands are likely undergoing lateral expansion.
• Expanding peatlands may represent an increasing natural carbon sink.
• Warming temperatures and longer growing seasons are key drivers of this expansion.