In less than a month we will embark on the journey of a lifetime. We will cross the Pacific Ocean to Hawaii, the place where it was first discovered that our planet is warming. The longest observational CO2 record we have is from an observatory in Mauna Loa.
Here in 1958, Dr. Keeling began to take measurements of CO2 concentration in the atmosphere. This lead to an alarming discovery: The CO2 concentration in the atmosphere is rising*. And further, even in remote places such as an island in the middle of the Pacific, we can clearly see the impact of humanity on the climate system.
This is the famous Keeling curve. Did you notice two things as you looked at the graph?
- CO2 concentration rises over time and increases more and more rapidly.
- CO2 has a seasonal cycle. While the overall trend increases, we can see a cycle each year. This corresponds to plants’ growth cycle. In the spring when plants grow and bloom, they start taking up excess CO2 reducing the total concentration. In the fall and winter when plants decay, the CO2 concentration increases again.
Now this record is very interesting but let’s take a look at CO2 over a longer time period***.
We can really put into perspective the enormous human induced rise in CO2 when we look over thousands of years. Here is the CO2 concentration over the last 10,000 years*. Before the industrial revolution (1850’s), CO2 is very low. Following the industrial revolution, CO2 starts to increase rapidly.
Let’s look over an even longer time period. Wow, looking at the last 800,000 years we can really see what a dramatic impact we have had on CO2.
While there are large millennial scale natural cycles in CO2 concentration, we have already exceeded all of the previous peaks in the last 800,000 years. Another thing that’s really important to notice is how quickly we are increasing CO2. This has all happened within the last 100 years. In this entire 800,000 year span, CO2 has NEVER increased so rapidly before. Give this a minute to sink in. We are entering an unknown world.
… and for this reason we are crossing an ocean.
- *To access the CO2 plots, visit: https://scripps.ucsd.edu/programs/keelingcurve/
- **What is ppm? ppm stands for parts per million and is the standard way to measure greenhouse gases. It is a ratio of one gas to another. For example, 1,000ppm of CO2 means that if you counted a million molecules in the air, 1,000 of them would be CO2 and the remaining 999,000 molecules would be some other gases.
- ***How do you measure CO2 concentration so long ago? Good question! The Keeling curve was constructed from direct measurements but the other plots used data from a different source. They used something called proxy data. Some examples of proxy data are ice cores, tree rings, and coral. From this data we can reconstruct what the CO2 concentration of the earth was a long time ago. For more information about proxy data visit: https://www.ncdc.noaa.gov/news/what-are-proxy-data
Don’t forget to check out the other pages on our blog including more about us, the race, and of course the donation page 😉