The Evolution of Earth's Atmosphere

• 4.6 billion years ago: Earth formed from a cloud of gas and dust called the solar nebula.

• Accretion: Small particles collided and stuck together, forming planetesimals and eventually the Earth.

• Outgassing: see next few pages

The Formation of Earth

Outgassing

Trivia: Outgassing is the process that led to the release of gases, including water vapor, carbon dioxide, and nitrogen, creating the early atmosphere. It occurred during the formation of Earth, as the planet's interior heated up and released gases from its molten state. This process played a crucial role in shaping the composition of our atmosphere today.

Outgassing Gases

Nitrogen was primarily released during outgassing. Other gases released include Methane, Oxygen, and Carbon Dioxide. Outgassing is the process of releasing trapped gases from a material, often occurring during volcanic eruptions or the formation of planets. Nitrogen, a key component of Earth's atmosphere, played a significant role in the early development of our planet.

Outgassing: Volcanic activity released gases, including water vapor, carbon dioxide, and nitrogen, creating the early atmosphere.

Great Oxygenation Event

​see next page

The Great Oxidation Event

• The Great Oxidation Event was a significant increase in oxygen levels in Earth's atmosphere around 2.4 billion years ago.

• This event was caused by the emergence of cyanobacteria, which released oxygen through photosynthesis.

• It led to the oxidation of Earth's surface, creating new minerals and changing the composition of the atmosphere.

• The Great Oxidation Event had a profound impact on the evolution of life on Earth, paving the way for the development of complex organisms.

The Great Oxidation Event

The Great Oxidation Event around 2.4 billion years ago led to a significant increase in oxygen levels in Earth's atmosphere. This event marked the transition from an oxygen-poor to an oxygen-rich atmosphere, paving the way for the development of complex life forms. It was a turning point in Earth's history.