Phase 2: Formation of Oceans and Carbon Sequestration

The second phase of atmospheric evolution was marked by significant changes in the Earth's surface and composition. This period saw the formation of oceans and the beginning of carbon sequestration processes.

As the Earth cooled, the water vapor in the atmosphere began to condense, forming the planet's oceans. This process had a profound effect on the atmospheric composition, as large amounts of CO₂ were removed from the air by dissolving in the newly formed oceans. The dissolved CO₂ underwent a series of chemical reactions, forming carbon precipitates that settled on the seabed as sediments.

During this phase, the first green plants and algae evolved. These organisms played a crucial role in further reducing atmospheric CO₂ levels by absorbing it for photosynthesis. Some of the carbon absorbed by these early life forms eventually became fossil fuels after their death and burial.

Definition: Carbon sequestration - The process of capturing and storing atmospheric carbon dioxide.

Example: The formation of limestone deposits on the ocean floor is an example of natural carbon sequestration.

Greenhouse Gases and Climate Change

Greenhouse gases, primarily CO₂, methane, and water vapor, play a significant role in regulating Earth's temperature. These gases act as an insulating layer in the Earth's atmosphere, trapping heat and contributing to the greenhouse effect.

The impact of greenhouse gases on climate change is substantial. These gases don't absorb short-wavelength radiation but do absorb and re-radiate long-wavelength radiation in all directions, including back to Earth. This process, known as the greenhouse effect, warms the planet.

Human activities have significantly increased the concentration of greenhouse gases in the atmosphere, leading to accelerated climate change. Some key factors contributing to this increase include:

1. Burning of fossil fuels
2. Deforestation, which reduces CO₂ absorption through photosynthesis
3. Agriculture, particularly livestock farming, which increases methane emissions
4. Waste creation and decomposition, releasing CO₂ and methane

Highlight: The impact of greenhouse gases on climate change is evident in rising sea levels, changes in rainfall patterns, and increased frequency and severity of storms.