Global lake thermal regions shift under climate change.

Area of Science:

• * Limnology and climate science.
• * Global aquatic ecosystem analysis.

Background:

• * Lake temperature is a key ecological factor, but predicting its variations is difficult without a thermal classification system.
• * Existing global patterns do not fully capture lake thermal dynamics.

Purpose of the Study:

• * To establish an objective, globally applicable lake thermal classification system.
• * To project future shifts in lake thermal regions under different climate change scenarios.

Main Methods:

• * Objective analysis of seasonal surface temperature dynamics from satellite observations.
• * Application of a lake model driven by 21st-century climate projections (Representative Concentration Pathways 2.6, 6.0, and 8.5).

Main Results:

• * Identification of nine distinct, globally contiguous lake thermal regions.
• * Projected shifts in lake thermal regions by 2080-2099: 12% (low), 27% (medium), and 66% (high greenhouse gas scenarios).
• * A potential 79% reduction in the northernmost thermal region under high emissions.

Conclusions:

• * The new thermal region framework provides unique insights into global lake thermal patterns.
• * Climate change is projected to significantly alter lake thermal regimes worldwide.
• * This classification system can advance global lake research and ecological predictions.