For hundreds of millions of years, Earth’s climate has warmed and cooled with natural fluctuations in the level of carbon dioxide (CO₂) in the atmosphere.
What kickstarted this dramatic change in global climate?
At the same time, at ocean trenches — where two plates converge — plates are pulled down and recycled back into the deep Earth. On their way down they carry carbon back into the Earth's interior, but also release some CO₂ via volcanic activity. In the transition to the Cenozoic icehouse climate tectonic plate movement slowed down and volcanic CO₂ emissions began to fall. But to our surprise, we discovered a more complex mechanism hidden in the conveyor belt system involving mountain building, continental erosion and burial of the remains of microscopic organisms on the seafloor.Tectonic plates slow down due to collisions, which in turn leads to mountain building, such as the Himalayas and the Alps formed over the last 50 million years.
As new mountain chains formed, more rocks were eroded, speeding up this process. Massive amounts of CO₂ were stored away, and the planet cooled, even though some of these sediments were subducted with their carbon degassing via arc volcanoes.