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What is the primary cause of recent increases in atmospheric carbon dioxide levels?
What is the primary cause of recent increases in atmospheric carbon dioxide levels?
Answered
The primary cause of recent increases in atmospheric carbon dioxide (CO₂) levels is human activities, particularly the combustion of fossil fuels and deforestation. Here’s a detailed explanation of these factors:
1. Combustion of Fossil Fuels
- The burning of fossil fuels such as coal, oil, and natural gas for energy production is the largest source of anthropogenic CO₂ emissions. This process releases significant amounts of CO₂ into the atmosphere as carbon from these fuels combines with oxygen during combustion. According to estimates, fossil fuel combustion accounts for approximately 87% of human-produced CO₂ emissions.
- The industrial revolution marked a significant increase in fossil fuel use, leading to a dramatic rise in atmospheric CO₂ concentrations—from about 275 parts per million (ppm) in 1750 to over 415 ppm today.
2. Deforestation
- Deforestation contributes to increased CO₂ levels by reducing the number of trees available to absorb carbon dioxide through photosynthesis. When forests are cleared for agriculture, urban development, or other uses, not only is this carbon absorption capacity diminished, but the act of burning or decomposing trees also releases stored carbon back into the atmosphere.
- Deforestation accounts for about 9% of global CO₂ emissions, making it a significant factor alongside fossil fuel combustion .
3. Increased Vehicle Emissions
- The rising number of vehicles and increased transportation activities also contribute to higher CO₂ levels. Transportation is a major source of greenhouse gas emissions, primarily due to the combustion of gasoline and diesel fuels .
Summary
In summary, the primary causes of recent increases in atmospheric carbon dioxide levels are:
- Excessive use of fossil fuels: This includes energy production, transportation, and industrial processes.
- Deforestation: The loss of forests reduces carbon sequestration and releases stored carbon.
- Increased vehicle emissions: Growing transportation needs contribute additional CO₂.
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