According to the Gaia hypothesis, which was proposed by the scientists Lovelock and Margulis in the 1970s, our planet should have been getting progressively warmer for millions of years, while our oceans should have been progressively more acidic as well. The fact that this hasn't happened suggests a planet-wide complex system that is self-regulating, with planetary life and geological processes working together to stabilize planetary geology and climate. Despite its importance, this idea could not be previously tested due to its planetary scale.