It’s not every day that high school students get to attend a class taught by a Nobel Laureate. But that’s just what happened for environmental science students at Jupiter High School recently. In the process, they got to shoot the breeze with Dr. Martin Heimann, and hear about a lot of hot air.
Heimann, Max Planck Institute for Biogeochemistry director, served as a lead author in assessment reports of the Intergovernmental Panel on Climate Change. Along with 2,000 scientists on that board, he was awarded the Nobel Peace Prize in 2007.
Focusing on the carbon cycle and its link to climate, he knew the students already had an understanding of the Greenhouse Effect. “It’s not a new idea,” Heimann said. “Arrhenius discovered it more than a hundred years ago. When sunlight penetrates the atmosphere, the energy is absorbed on the surface of the earth and warms it. The heat is returned in terms of infrared radiation and that is CO2.
“If you change the amount of gas, you warm the atmosphere more. It’s like the blanket that covers you at night and so the earth is receiving heat both from the sun and the atmosphere.”
The Keeling Graph, tracking data recorded at the Mauna Loa Hawaii laboratory since 1958, shows the steady rise of CO2 as well as seasonal variations, he told the students. A red zigzag line goes catty-corner from the bottom left to the upper right. A blue line runs through it.
The red zigzag line tracks CO2 in the northern hemisphere. The blue line tracks it in the southern hemisphere “Plants like CO2, so there’s less of it in the atmosphere during the summer. In the northern hemisphere, there’s more foliage, that’s why the line shows more variation,” he said.
Before 1958, when scientists didn’t have instruments to measure PPM (molecule parts per million), scientists took measurements from ice cores, he explained.
Snow is porous and when it freezes, air is captured in the bubbles. Scientists can take a core sample, count the layers from each winter freeze to figure age, and then analyze the air that the ice has stored away in its pockets. After looking over layers representing thousands of years in the Vostok Core, scientists saw that CO2 and temperature (or the climate system) are linked together.
“It’s kind of like the chicken-and-egg scenario,” Heimann said. “We do not fully understand the relationship; it’s a topic we want to study. “But what’s important is that CO2 concentration over the last 8,000 years was never as high as it is today. We are running a new system now.”
Humans are the driving force behind this, he said. “We are burning fossil fuel at a rate of one billion tons a year.”
Deforestation also contributes to the high CO2 levels, he said, because burning forests puts CO2 in the atmosphere. And although this is happening in developing countries, be careful about pointing fingers. He asked the students, “Where do you get your shoes? India, Taiwan, China. They are producing for us. This has to be taken into account and this is one of the complications in this field.”
The amount of CO2 that is emitted into the air is another mystery that scientists are trying to unravel. “About 50 percent does not stay in the atmosphere. The earth system passes things out. We want to know about those processes, how they will acerbate, and how they will change over time.”
The scientists study the flux between land, water, atmosphere and CO2. Measuring how much CO2 gets pushed into the ocean by the atmosphere can be done by ships, he said, but scientists don’t have a technique to measure what goes into land.
“We came up with a project about the carbon balance (that takes into consideration) emissions, the burning of fossil fuels, deforestation and changes in land use. We’ve found about 47 percent stays in the atmosphere and 36 percent is taken up by land, vegetation and some in the ocean. Computing over time, the amount remains the same. We want to understand why this stays so constant.”
written for Palm2Jupiter