How does the presence of CO2 in the atmosphere contribute to global warming?

The presence of carbon dioxide (CO2) in the atmosphere contributes to global warming by increasing the greenhouse effect. This greenhouse effect occurs when certain gases, including CO2, trap heat from the Earth's surface, preventing it from escaping back into space. These gases absorb infrared radiation emitted by the Earth and re-radiate it in all directions, including back towards the surface. This process results in an overall warming of the atmosphere and surface temperatures.

As CO2 concentrations rise due to human activities such as burning fossil fuels and deforestation, more heat is trapped, leading to an increase in global temperatures. This phenomenon is a significant driver of climate change, as it affects weather patterns, sea levels, and ecosystems across the planet.

While other options present different environmental effects, they do not accurately describe the primary role of CO2 in global warming. The cooling of the planet, depletion of the ozone layer, and increased precipitation are not directly related to the action of CO2 as a greenhouse gas.