Understanding Earth's Climate System

Earth's climate system is incredibly complex, involving atmospheric layers, ocean currents, and terrestrial ecosystems, all interconnected through the energy balance with the sun.

Throughout Earth's history, CO2 levels have fluctuated naturally. However, since the Industrial Revolution, human activities have increased atmospheric CO2 from 280 to over 410 ppm.

Oceans absorb about 30% of emitted CO2, leading to acidification. This subtle pH change disrupts marine life, affecting shell formation in organisms like corals and mollusks.

Thawing permafrost releases methane, a potent greenhouse gas. This feedback loop can accelerate warming, yet the extent of permafrost carbon stocks remains a wild card in climate models.

Greenland's ice sheet is melting, contributing to sea level rise. Surprisingly, the meltwater forms dark pools that absorb more sunlight, further accelerating the ice loss in a self-reinforcing cycle.

Clouds have a dual role in climate: high, thin clouds trap heat, while low, thick clouds reflect sunlight. Their net effect on global warming is one of the largest uncertainties in climate predictions.

Forests sequester carbon but are threatened by deforestation and climate-induced wildfires. Surprisingly, they also create biogenic volatile organic compounds (BVOCs) that have a cooling effect on the atmosphere.