The ice-albedo feedback loop demonstrates how melting ice darkens Earth's surface, causing it to absorb more sunlight and warm further — accelerating still more melting. Move the temperature slider and toggle the feedback loop to compare stable, slider-driven melting against a self-reinforcing runaway.
Albedo — the fraction of sunlight a surface reflects — differs hugely between bright ice (0.6–0.9) and dark ocean (~0.06). As ice retreats, the average albedo drops, absorbed solar energy rises, and (with feedback on) that extra energy drives further warming and melting: a positive feedback loop.
Drag the temperature slider to add warming forcing. With feedback ON, watch the ice keep shrinking on its own after you stop moving the slider. Switch feedback OFF to see the same slider produce only proportional, stable melting.
The Arctic is warming two to four times faster than the global average, a phenomenon called polar amplification — driven in large part by exactly this ice-albedo feedback.
This canvas simulation models a simplified cross-section of ice caps over open ocean, driven by a temperature-anomaly slider. Albedo — the fraction of incoming sunlight a surface reflects — is very different for the two surfaces: fresh ice and snow reflect roughly 60–90% of sunlight, while open ocean reflects only about 6%, absorbing the rest. As temperature rises, the model shrinks the ice fraction, which lowers the blended average albedo and raises the energy absorbed by the surface.
The key feature is the optional feedback loop. When enabled, extra absorbed energy (above a baseline) is fed back each tick as additional warming, which melts more ice, which lowers albedo further — a positive feedback that can run away even without more external forcing, until the ice is gone or the system finds a new balance. Switching feedback off removes this self-reinforcement, so the same temperature slider produces only direct, proportional melting. This contrast mirrors a real driver of polar amplification, the observed effect where the Arctic warms several times faster than the global average.
What is albedo?
Albedo is the fraction of incoming sunlight a surface reflects rather than absorbs, expressed as a number from 0 (absorbs everything, like a black surface) to 1 (reflects everything, like a mirror). Fresh snow and ice have a high albedo of roughly 0.6 to 0.9, while open ocean has a low albedo of around 0.06, so it absorbs almost all the sunlight that reaches it.
What is the ice-albedo feedback loop?
It is a chain reaction in which warming melts ice, exposing darker ocean or land underneath. The darker surface absorbs more solar energy than the ice did, which causes further warming, which melts more ice, and so on. Because each step reinforces the next, it is called a positive feedback loop, and it can accelerate warming well beyond what the initial temperature change alone would cause.
Why does the ice keep shrinking even after I stop moving the slider?
When the feedback toggle is on, the simulation feeds the extra absorbed energy back into the effective temperature on every animation tick. That small added warming melts a bit more ice, which lowers albedo and increases absorption again, so the loop keeps nudging the temperature upward on its own until it reaches a new equilibrium or the ice fully melts — a visible runaway effect driven purely by the feedback, not by further slider input.
The temperature slider sets the external warming forcing that establishes the baseline ice fraction; the feedback toggle switches the self-reinforcing warming-from-absorption effect on or off; the simulation speed control scales how quickly the feedback evolves per second; and reset restores the default temperature, refreezes the ice, and turns feedback back on.
Polar amplification is the observed tendency for polar regions, especially the Arctic, to warm two to four times faster than the global average. The ice-albedo feedback is one of the leading causes: as sea ice and snow cover shrink, the darker exposed ocean and land absorb much more solar energy, amplifying local warming beyond the global trend.
With feedback off, the ice fraction responds only directly to the temperature slider's position through the same clamp-based melt formula, and no extra energy is fed back into the temperature. So each slider position maps to one stable ice fraction and albedo — moving the slider changes the ice amount proportionally, but the system never accelerates on its own the way it does with feedback enabled.
No. This is a simplified, pedagogical model of one specific mechanism — the ice-albedo feedback — using a small set of equations relating temperature, ice fraction, albedo and absorbed energy. Real climate models include many additional feedbacks (water vapour, clouds, ocean heat transport, carbon-cycle responses and more), so this simulation is meant to build intuition for one important piece of the bigger picture rather than to forecast real-world climate.