500 million years of climate history pinned on plate tectonics

Indonesia's Paluweh volcano sits in a region of colliding tectonic plates—perhaps the formula for glacial periods in geologic history.

Enlarge / Indonesia’s
Paluweh volcano sits in a region of colliding tectonic
plates—perhaps the formula for glacial periods in geologic
history. (credit:
Robert Simmon/NASA Earth Observatory
)

Generally speaking, it’s easy enough to make sense of the last
few million years of climate patterns—the world looked much as it
does today, so changes in greenhouse gas concentrations or ocean
circulation can be related to what we see now. But as you go back
farther in time, you can find very different climates and a
rearranged map of continents, and those require more creative
thinking.

For example, the ice age periods in the recent past are not
unique. But most of the last 500 million years have been much
warmer—what has caused the climate to slowly drift toward warmer
or cooler temperatures over millions of years?

Looping

In the grand sweep of Earth history, its climate has remained
within a habitable temperature range—thanks in part to the
moderating influence of feedback loops within the system. The
weathering of silicate minerals in bedrock pulls CO2 out of the
atmosphere, for example. In a warming climate, weathering can speed
up, removing more greenhouse gas and stabilizing temperatures. Cool
the planet and weathering slows, giving greenhouse gases more
chance to accumulate.

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Source: FS – All – Science – News
500 million years of climate history pinned on plate tectonics