Global lake phytoplankton proliferation intensifies climate warming

Area of Science:

• Environmental Science
• Climate Science
• Limnology

Background:

• Phytoplankton in lakes capture atmospheric carbon dioxide (CO2), converting it into biomass organic carbon (OC).
• A significant portion of this OC is recycled back into the atmosphere as CO2 and methane (CH4), potent greenhouse gases.
• Methane (CH4) possesses a higher radiative forcing than CO2, contributing to a warming effect and CO2-equivalents (CO2-eq).

Purpose of the Study:

• To investigate the impact of climate warming on greenhouse gas emissions from lakes.
• To quantify the feedback loop between phytoplankton activity, CO2-eq emissions, and global warming.

Main Methods:

• Analysis of carbon cycling processes in lake ecosystems.
• Modeling of greenhouse gas emissions (CO2 and CH4) under varying climate warming scenarios.
• Assessment of CO2-equivalents (CO2-eq) over a 100-year time horizon.

Main Results:

• A 3.1-fold increase in CO2-eq emissions was observed over a 100-year period.
• The magnitude of CO2-eq emissions increases with global warming intensity.
• Climate warming stimulates phytoplankton growth, creating a positive feedback loop for CO2-eq emissions in many lakes.

Conclusions:

• Lakes can act as a source of greenhouse gases, potentially amplifying climate warming.
• The positive feedback loop between phytoplankton and CO2-eq emissions is sensitive to global warming intensity.
• In some lakes, climate warming may negatively impact phytoplankton, potentially reducing CO2-eq feedback capacity over time.