At least twice in Earth's history, almost the entire planet was encased in a layer of snow and ice. These dramatic "Snowball Earth" / Tierra Bola de Nieve events occurred in rapid succession, somewhere around 700 million years ago, and evidence suggests that consecutive global ice ages set the stage for the subsequent explosion of complex, multicellular life. on earth. Scientists have considered multiple scenarios for what may have tilted the planet in each ice age. While no single driving process has been identified, it is assumed that what caused the temporary freezes must have done so in a way that pushed the planet past a critical threshold, such as reducing incoming sunlight or atmospheric carbon dioxide. at levels low enough to establish a global ice expansion. New theory But MIT scientists now say that the Snowball Lands were likely the product of "speed-induced ice ages." That is, they discovered that the Earth can slip into a global ice age when the level of solar radiation it receives changes rapidly in a geologically short period of time. The amount of solar radiation does not have to fall to a particular threshold point; As long as the decline in incoming sunlight occurs faster than a critical rate, a temporary glaciation, or Snowball Earth, will follow. What triggered the Earth's ice ages likely involved processes that rapidly reduced the amount of solar radiation reaching the surface, such as widespread volcanic eruptions or biologically-induced cloud formation that could have significantly blocked the sun's rays. suggests that these planets, like Earth, could also temporarily freeze if their climate changes abruptly. Even within a habitable zone, Earth-like planets may be more susceptible to global glaciations than previously thought.
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Source: Proceedings of the Royal Society / MIT/Constantin Arnscheid, Department of Earth, Atmospheric and Planetary Sciences at MIT. (EAPS).
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