How glacier ice algae accelerate Greenland ice sheet melting

Sub: Geo

Sec: Geomorphology

Context:

A new study reveals that dark-pigmented microalgae, which contribute to the melting of the Greenland Ice Sheet, are highly efficient in nutrient uptake and growth, allowing them to rapidly colonise expanding areas of exposed ice, intensifying ice sheet darkening and accelerating melting rates.

Key Findings:

Nutrient Efficiency of Microalgae: The study utilized cutting-edge single-cell imaging techniques to analyse the carbon, nitrogen, and phosphorus content of glacier ice algae. It was found that these algae are capable of surviving in nutrient-poor glacier environments by storing phosphorus internally and maintaining high carbon-to-nutrient ratios. This indicates that the algae have a survival strategy finely tuned to extreme conditions, where nutrients are limited.
Self-Sufficiency in Nutrient Uptake: The research highlights that these algae do not require large amounts of external nutrients to grow, allowing them to thrive as more bare ice is exposed due to the melting of the ice sheet. This self-sufficiency suggests that the algae are well-positioned to expand and colonize additional areas of the Greenland Ice Sheet.
Impact on Ice Sheet Melting: The dark pigmentation of these algae lowers the reflectivity of the ice, increasing heat absorption, which in turn accelerates the melting of the ice sheet. This process is particularly concerning as it contributes to rising sea levels.

Greenland Ice sheet:

Greenland Ice Sheet is the single ice sheet or glacier covering about 80 percent of the island of Greenland and the largest ice mass in the Northern Hemisphere.
The Greenland Ice Sheet is the second-largest ice sheet in the world after Antarctica, covering about 1.7 million square kilometres in Greenland.
The melting of the Greenland Ice Sheet is the single largest contributor of freshwater to global sea level rise. It is estimated to hold approximately 7 meters of potential sea-level rise if it were to completely melt.