Table of Contents

• Section 1: Keeling's 50 year curve
• 1: How would YOU measure CO₂?
• 2: How Keeling measured CO₂
• 3: Parts per what?
• 4: Roadtrip anyone?
• 5: Let's go to Hawaii
• 6: The Keeling Curve at 3 (years old)
• 7: The Keeling Curve at 50
• Section 2: Reading Keeling's Curve
• 8: Within vs. between year fluctuations
• 9: Do the fluctuations change?
• 10: Past and future
• 11: 80% reduction in CO₂ emissions

What would happen if we stopped emitting CO₂?

What if (in a miraculous change of heart) the U.S. suddenly took the lead to unilaterally reduce CO₂ emissions, which convinced the rest of the world to follow suit, and CO₂ emissions fell to zero in the space of a single year?

In this all-but-impossible scenario, what would happen to atmospheric CO₂? Would it also drop to zero?

Remember that human emissions are only a small part of the CO₂ that goes into the atmosphere every year -- but the rest of the cycle is in balance. So, that means that without human emissions, CO₂ levels would stay -- but at their CURRENT, historically high, level.

Would the "extra" CO₂ that we've added eventually leave the atmosphere ... in other words, will it go away on its own? This is a difficult question to answer, because there are a lot of processes involved in the long-range CO₂ cycle:

• 20 to 200 years: some CO₂ will dissolving in the ocean
• 5000 years: some CO₂ will react with chalk in ocean to form sediments
• 400,000 years: last 25% of CO₂ will disappear through rock weathering

Some people have compared this to a 400,000 year hangover...