Final answer:
Photosynthesis, oceanic absorption, geological storage, and technological solutions like direct air capture and carbon capture are main processes that remove CO₂ from the atmosphere.
Step-by-step explanation:
The main processes that remove carbon dioxide from the atmosphere include photosynthesis, where trees and plants absorb CO₂ and convert it into organic matter, the dissolution of CO₂ in oceans forming carbonate and bicarbonate, the formation of long-term geological carbon stores through processes like sedimentation, and new technologies such as direct air capture and carbon capture at point sources such as smokestacks. Photosynthesis is a particularly critical process, as it not only removes CO₂ but also produces oxygen, which is essential for life on Earth. However, deforestation significantly impairs this natural ability to sequester carbon. The adoption of various anti-pollution policies has also contributed to a significant reduction in carbon emissions, as shown by the decline of emissions in the United States from 2007 to 2012 by 740 million metric tons or a 12% reduction.