Impact of Human Activity on Carbon Emissions

Oct 19, 2024

Lecture Notes: Human Activity and Carbon Emissions

Introduction

  • Focus: Investigating the carbon produced by human activity.
  • Remarkable increase in global temperatures due to CO2 spike.
  • Current atmospheric carbon levels are the highest in at least 3 million years.

Human Contribution to Carbon Emissions

  • Human Activities Producing CO2:
    • Burning fossil fuels (composed of hydrogen and carbon).
    • Industrial processes (e.g., cement production).
  • Historical Emission Data:
    • Since the industrial revolution: 1.5 trillion tonnes of CO2.
    • Recent trend: 36 billion tonnes annually.
    • 50% of emissions occurred since 1988.

Comparing Human and Natural Emissions

  • Natural CO2 Emission Sources:
    • Volcanic activity, respiration, decomposition.
    • Total: 750 billion tonnes annually.
  • Human vs Natural Emissions:
    • Humans contribute less than 5% to total emissions.
    • Natural processes have checks and balances (e.g., photosynthesis cancels out respiration).
  • Impact of Human Activity:
    • Human emissions disrupt the natural balance.
    • Carbon from fossil fuels is released faster than it can be reabsorbed.

Evidence of Human Responsibility

  • Chemical Signature Evidence:
    • Increase in atmospheric carbon 12 (organic carbon) points to fossil fuel burning.
    • Natural events affecting carbon (e.g., flood basalts, permafrost melting) are not occurring at necessary scales.
  • Isotopic Analysis:
    • Carbon in the atmosphere increasingly matches the signature of fossil fuels.
    • Organic carbon (enriched in carbon 12) must come from a non-interacting source: fossil fuels.

Scale of Human Impact

  • Humans have released 1.5 trillion tonnes of CO2, translating to about 400 billion tonnes of pure carbon.
  • This is equivalent to two-thirds of all plant carbon on land.

Conclusion

  • Overwhelming evidence indicates human activity is the primary cause of the recent rise in CO2.
  • The lecture underscores the significant role humans play in climate change.
  • Final thoughts: Engage with content and spread awareness.
  • Note: These notes are based on a video lecture and provide a summary of critical points regarding human carbon emissions and their impact on the global climate.