In DepthClimate

Tropical uplift may set Earth's thermostat

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Science  04 Jan 2019:
Vol. 363, Issue 6422, pp. 13
DOI: 10.1126/science.363.6422.13

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Summary

Many mountains in Indonesia and neighboring Papua New Guinea consist of ancient volcanic rocks from the ocean floor that were caught in a colossal tectonic collision between a chain of island volcanoes and a continent, and thrust high. Lashed by tropical rains, these rocks hungrily react with carbon dioxide (CO2) and sequester it in minerals. That is why, with only 2% of the world's land area, Indonesia accounts for 10% of its long-term CO2 absorption. Its mountains could explain why ice sheets have persisted, waxing and waning, for several million years. Now, researchers have extended that theory, finding in work presented at a meeting of the American Geophysical Union in Washington, D.C., that such tropical mountain-building collisions coincide with nearly all of the half-dozen or so significant glacial periods in the past 500 million years. If Earth's climate has a master switch, the rise of mountains like Indonesia's could be it.