Penguin Poop Turns Snow Green

In Antarctica, some snow isn't white. It's red, or even bright green. The color comes from tiny algae living in the snow, and a new study says penguins help keep it green. Here's how. Penguins eat fish and krill at sea, then waddle back to land and leave plenty of poop, called guano, all over the snow. That guano is packed with a nutrient called phosphate, which works like fertilizer. Scientists sailed along the Antarctic Peninsula and scooped up colored snow near penguin colonies and far from them. Where the algae was green, there was far more phosphate. When food runs low, the algae turns red to protect itself from the sun. Why it matters: green snow soaks up about forty percent more sunlight than clean white snow, so it melts faster. The researchers say melt forecasts don't include this effect yet. Even penguin poop shapes the planet.