Science 
The Witness Tree: “A tree that has witnessed historic events. A tree used to
Photo Credit: Carolyn Monastra - Lake Erie # 5, 2010
Any “witness trees” in your life? Artist Carolyn Monastra’s current body of work is called the Witness Tree.….
“..my eyes and my camera will also act as witnesses and the resulting pictures will serve as permanent documents of these precious and precarious environments that are being affected by climate change.”
Carolyn Monastra, 2011
This is the second, of our “occasional check ins” with, about and by Carolyn as we follow her journey documenting climate change around the world. Recently Carolyn visited the Big Island of Hawaii and the Mauna Loa Observatory, something our Climate Mama, Harriet did, this past December! See what Carolyn has to say about this interesting and important place, where data on carbon dioxide levels in our atmosphere has been recorded on a daily basis for more than 50 years!
The following post is taken with permission from Carolyn’s The Witness Tree Photography Blog. These photographs are ours. To see Carolyn’s photos, visit the Witness Tree!
Part 1: Monitoring Carbon Dioxide
I went to Hawaii on a pilgrimage. Not to discover whales or surf the big 
waves but to visit the Mauna Loa Observatory on The Big Island. Most people, locals included, are more familiar with the shiny astronomy observatories located on the nearby Mauna Kea, the highest mountain in the Pacific. But I was interested in this lesser-known research station on this slighter lower but larger volcano. The Mauna Lao Observatory (MLO) was established in the late 1950’s by scientist Charles Keeling to measure and study the amount of carbon dioxide in the atmosphere.
I was lucky enough to be touring the facilities on the same day as Dr. Kevin Harrison who had been a student of Dr. Keeling. In continuing the lineage to Keeling our guide was Aidan Colton a former student of Kevin’s. I felt like I was among climate change science royalty. Kevin and his girlfriend Beth graciously agreed to drive me up to the lab since there is no public transportation to get there. It was a bright warm winter day when we started out in Hilo, but the temperature dropped considerably by the time we got to the lab. And since Mauna Loa (translated as long mountain) is more than 13,680 ft / 4,170 m above sea level we also noticed that the thin air caused us to feel a bit light-headed.
Keeling chose to build this lab in Hawaii since he wanted to a place where the atmosphere was not polluted to ensure the accuracy of his measurements. In addition to Keeling’s original carbon dioxide analyzer, NOAA (National Oceanic and Atmospheric Administration) also funds a newer separate CO2 monitoring device. The complex of several buildings are part of the Earth System Research Laboratory – Global Monitoring Division (GMD) based in Boulder, Colorado. The GMD consists of several projects focusing on different but related issues that affect climate change: such as The Aerosol and Radiation Group and the Ozone and Water Vapor Group.
After seeing the fancy shiny observatories at Mauna Kea the day before I was surprised by the Rube Goldberg appearance of these facilities. The 
complex is made up of several corrugated metal and wood buildings. Yet despite the simple construction of the labs, the work they do there is very important in monitoring the rising rate of carbon dioxide in the atmosphere. The MLO is responsible for the longest continuous record of atmospheric CO2 in the world.
A little background
Before the industrial revolution the amount of CO2 in the atmosphere was a steady 275 parts per million (ppm) for about 10,000 years. When Keeling started his studies, that number was 315 ppm. On the day I visited it was 396 ppm with the average so far for this year being 391. Aidan explained they always work with averages collected over many days rather than using any one number that might signify a high or low spike. The staff is also careful to disregard any false numbers that may be influenced by other particulates in the air such as when extra sodium dioxide is blowing downwind from nearby volcanoes.
One of the first things Keeling noted from the early measurements is that the concentration of C02 varies seasonally reflecting the growth and decay of vegetation in the Northern Hemisphere. Hence in the spring the level drops as leafy trees and plants absorb more atmospheric C02 and in autumn the concentrations begin to increase again as trees become bare. And more importantly, over time the Keeling Curve, as it’s become known, has shown connections between the increase in the global combustion of fossil fuels and the concentration of atmospheric carbon dioxide.
Even though we don’t need scientific charts to tell us that the climate is changing, lining up the Keeling Curve with one showing the increase in global temperatures underscores the relationship between the two.
Polar ice is melting, sea levels are rising, and storms are getting worse. And some of these effects have further feedback loops: For example, as the reflective white surface of ice sheets melt leaving more dark sea to absorb heat, ocean temperatures are also increasing. And it’s not just the atmosphere that is absorbing more carbon dioxide but the oceans as well.
Essentially the level of CO2 has risen steadily by 2ppm each year since the 1950’s and there has been more than a 37% increase since the Industrial Revolution level of 275 ppm. In the early years of climate change studies, scientists thought that number could safely increase to 550 ppm. But as more studies were done that number was lowered to 450. Then in 2007 NASA scientist James Hansen announced that 350 ppm is the highest level that the earth can safely sustain. Since we surpassed that number several years ago we need to work hard to try to get it back down. Pessimists might say that it’s too late. But people like activist Bill McKibben (who started the group 350.org) believes in focusing our efforts to motivate politicians to take action instead of just making hollow promises.
Reading McKibben’s books The End of Nature and Eaarth and Hansen’s Storms of my Grandchildren made me aware of how important the studies at Mauna Loa are. Both authors point out how dangerous it is to ignore this rising CO2 figure and just continue with a “business-as-usual” mentality. Even if we did change our dependency on fossil fuels overnight, much of the damage that has been done cannot be repaired. But I don’t think that is reason to give up the fight. I have followed the activities of 350.org for a couple of years now and am inspired by how strong their presence is worldwide. I urge you to check out their website and consider getting involved in a local chapter.
At the end of our tour he gave Kevin, Beth, and I each a glass tube to 
capture our own CO2 sample which he sealed and marked with the date and the current level of 396 ppm when we captured it. I periodically check NASA’s Vital Signs of the Planet website to monitor their current stories and statistics about climate change including concentrations of CO2 so I will check it with greater interest now that I have been to Mauna Loa. And I pray that the little vial of carbon dioxide on my shelf will become a relic of the past when/if the levels of carbon dioxide start dropping as we humans learn to curb our dependency on fossil fuels.
