Carbon: The Dance of Life
The recent debate over United States involvement in the Paris Agreement motivated the D2D team to look more closely at the changing climate and its effect on agriculture. Before we address climate change, we thought we would put CO2 under the microscope to understand the important role carbon dioxide plays in our food system.
At D2D, we think it is important to look at the effect weather patterns have on our environment and U.S. agriculture. We thought we would start with a discussion on the important role CO2 plays in our precious Earth. This tiny molecule is the primary focus of the discussion over climate change. Let’s take a closer look at what we cannot see…
We are made of the stuff of stars.
Not to get too groovy, but carbon originally rode the waves of stardust travelling through space to make its way to earth. All living things on Earth contain carbon as a significant atom. You would not be able to read this post without carbon as a building block of your DNA, fats, sugars, muscle tissue, and proteins. It is actually 18% of your overall body mass!
The Invisible Atmosphere.
The atmosphere is divided up into five layers. The bottom layer, or the ‘troposphere,’ where the majority of the gases are located. This is where we do our daily living. Depending on the location, it is between 4 to 12 miles thick.
Included in the troposphere is a mixture of nitrogen and oxygen, comprising approximately 98% of the gases. Alternatively, greenhouses gases (one of which is CO2) account for approximately 2% of gas in the troposphere. Even though carbon dioxide occupies an even smaller percentage (.04%), it still plays a very important role for life on Earth.
CO2 = the Elixir of Life.
CO2 is an important instrument in the band of life. Despite its humble percentage (.03%), carbon dioxide is crucial for the instrument of life. CO2 is responsible for providing all plants with the fuel they need to create their own food. The combination of one carbon atom and two oxygen atoms have essentially created the dance of life. There are two critical dances that more or less revolve around CO2.
Photosynthesis is the first of these two dances. All plants absorb CO2, water, and sunlight and turn it into glucose and carbohydrates. This allows the plants to create nutrients that energizes their growth. They then release the unneeded oxygen back into the atmosphere.
The CO2 fertilization effect. image: mother earth news
Humans are a perfect partner in this first dance as we inhale oxygen and exhale CO2! Plants emit the oxygen that all mammals breathe, and in turn, mammals exhale CO2 for the plants. Of course, plants don’t only provide us with oxygen— they are also humans major fuel supply as nutritious food we eat!
Photosynthesis then leads us to the second dance that takes place on a much larger floor. Picture the Earth as one giant convective movement of air and water. CO2 is inhaled by our vegetation, landmasses and oceans every single day. This process, called the Carbon Cycle, creates a balance of carbon in the atmosphere.
Where does this carbon dioxide come from?
There are two sources of CO2: natural and anthropogenic (man-made).
Naturally occurring CO2 comes from humans, bears, whales, dogs, and other mammals breathing in nitrogen, oxygen, argon, and CO2, and breathing out excess CO2 and small amounts of oxygen. Oceans, decomposing plant material, rock layers within the Earth’s surface, and forest and grass fires are all natural CO2 emitters. However, the biggest sources are deep sea vents and volcanoes.
Anthropogenic (human-induced) CO2 sources come from the burning of decomposed plants and animals that have been buried for millions of years – way before dinosaurs – and composited in the ground as oil, gas, and coal. As these species died and decomposed they became buried under layers and layers of mud, rock, sand and even ancient seas. Once burned as fossil fuels, the carbon is released back into the air.
It may seem obvious, but when we start a car, heat our home, electrify our cities, or send a rocket into space we are burning fossil fuels. Even beer, pizza, and soft drinks contribute to CO2.
Fun Fact: One acre of forest absorbs one car’s average annual use. And the forests in the U.S. are doing a great job as the U.S. has approximately 264 million cars and 752 million acres of forest.
Human use of fossil fuels contributes approximately 37 billion metric tons of CO2 each year – which is 5% of all atmospheric CO2. Approximately one-half of this amount is absorbed by plants and oceans. The other 2.15% (or 16 billion metric tons) is not absorbed and remains in the atmosphere as CO2. This extra CO2 is the focus of the greenhouse effect and climate change discussions.
CO2, along with other gases such as, water vapor, methane, and nitrous oxide are considered “greenhouse gases.” While greenhouse gases are good for life on Earth, those that are out of balance can affect the climate. These gases hold in the sun’s heat, which can be both good and bad. Without the greenhouse effect, the Earth’s average temperature would be about -0.4°F! Today, our average temperature is roughly 57.2°F. Climate change advocates insist that too much greenhouse gas will increase our global temperature by as much as 3.5°F.
The Earth System Research Laboratory monitors CO2 levels on Mauna Loa, Hawaii. Fluctuations in the atmosphere occur depending upon the growing season of all greenery on Earth. The carbon sinks of the ocean and the land use of CO2 is not always equal and the earth is not always in a complete balance. It depends upon the growing season, harvests, El Nino, and other climate factors.
Today there are about 400 parts-per-million (ppm) of CO2 in the atmosphere. Over the past 400,000 years, it has fluctuated between 200 to 300 ppm. It was only recently, within the past 115 years, that it began to consistently rise leading to a level just over 400 ppm in 2017. To put this into a different perspective, 400 ppm (.04%) of the total atmosphere is equal to $400 out of $1 million. It is because of this increase and the change in climate that many scientists associate CO2 with the warming of the Earth.
The Great Debate…
So, if CO2 is so integral to our daily life, and excess CO2 can be used by our plants— why are people so worried about the extra carbon in the atmosphere. And how does this relate to global warming?
The crux of the conversation is based on the fact that the Earth must maintain temperature equilibrium while it absorbs sunlight and emits infrared radiation back to space.
As we know, sunlight comes through the atmosphere, it heats the Earth’s surface that, in turn, emits infrared heat radiation. As the radiation rises, it penetrates atmospheric gases such as CO2, water vapor, methane, nitrous oxide, and other gases. These molecules then radiate the energy out into space or back to Earth. This process, called the greenhouse effect, is critical to maintaining temperatures on earth suitable for life as we know it.
Infrared radiation is divided out into different colors. As the temperature goes from violet, blue, green, yellow, orange, and red it gets hotter and hotter. You may also recognize infrared radiation for its use in heat sensors, thermal imaging, night vision, and LEDs. As humans, we always absorb and emit infrared radiation to keep our bodies at the correct temperature of 98.6 degrees. We glow invisible light, which is why we can be seen with night vision goggles.
Richard Lindzen, Atmospheric physicist and 30 year professor at MIT, adequately clarified the difference between scientific thinking on climate change. In short, scientists can be divided into two groups of thought:
Group 1 says… that any climate change is due to the burning of fossil fuels. The CO2 from these fossil fuels take on a ‘greenhouse’ effect on the Earth and will warm it at least 2°C.
Group 2 says… that there are many things responsible for a changing climate, such as convection in the atmosphere (moving clouds and wind), solar sun spots, ocean currents, orbital variations of the earth, and water vapor. They do not believe that the confluence of all these factors combined is fully understood.
Both groups agree that:
The climate is always changing
CO2 is a greenhouse gas without which life on Earth is not possible and adding it to the atmosphere should cause some warming
Atmospheric levels of CO2 have been increasing since the end of the little
ice age of the 19th century
Since 1800 – 2000 the global mean temperature has increased slightly and erratically by about 1°C or 1.8°F . But only since the 1960s have human’s greenhouse emissions been significant enough to play a role.
Given the complexity of climate, no confident prediction about future global mean temperature or its impact can be made., IPCC Report (In context that ‘we are dealing with a coupled non-linear chaotic system’)
Climate Change’s Role in Agriculture.
Civilizations have always experienced fluctuations in their crop yields and their ability to provide enough food for themselves due to changes in the climate. Some have flourished with warmer weather – and unfortunately, some have perished due to drought. Think of the Vikings who settled in Greenland to farm during a warm period and then had to leave due to an oncoming ice age. The European population expanded tremendously during the 10th to 15th centuries when long warm summers brought bountiful crops. The Mayans and ancient Egyptians didn’t fare as well when their great societies ended with parched drought.
The climate and farming are irrevocably linked. All of our food, both for ourselves and our animals need clean air, clean water and healthy soil. Some of these conditions are dependent upon how we take care of the environment and some of that will be a reaction to the change in climate.
Risky Business, a risk assessment committee on climate change, predicted that agricultural growing patterns will change significantly with hotter temperatures and rainfall variation. For instance, they have indicated that there will be an increase of days over 95 degrees in the mid-west and as a result are predicting crop losses of 18 to 24% in parts of the southern mid-west. Yet the opportunities for double cropping (two crops a season) are increased for a warmer northern mid-west.
There are a lot of opportunities and challenges related to our changing climate. At D2D, future posts, we will explore some of the latest research for the following questions…
- What is the full effect of CO2 fertilization for crops? Does it have the same impact on each of the major crops such as corn, soybeans, wheat, canola, and cotton?
- Will the CO2 fertilization benefit be offset by changes in temperature and rainfall?
- Will the seed companies be able to keep up with the change in climate, for instance producing hardier drought resistant crops?
- Will the public accept new technologies in breeding?
- How will our water system change and how will that impact crop location?
- What kind of technology will farmers need to adapt to stay profitable and in business?
- Will the logistic system such as grain elevators, transportation, and processing locations need location adjustment?
- Where will crops be grown in the future? For instance, will corn continue its stronghold in Iowa or will it slowly move north, leaving Iowa free for other crops?
- How will soil management and soil health play a role with changing temperature and rainfall? Will farmers be able to grow new crops with different soil needs? How does carbon sequestration play a role in mitigating CO2?
- How will global trade flows help in ensuring our food supply is resilient?
Whether climate change is CO2-related or not, we do know that weather patterns are always changing. Understanding the long-term trends is critical to feeding 9 billion people by 2050 with our existing resources. Resilience and adaptability will be important human characteristics to ensure our global food supply chain will thrive in different environments around the world than those that present themselves today. Global trade and keeping borders open so that the right crops can be grown in the right weather and soil environment is one large piece of the puzzle.
The Bottom Line:
CO2 is getting a bad reputation and when it comes down to it, it is essential for life on Earth. Without it we would look like Mars – no breath, no life, no water, no warmth, no trees, no rainfall. What we do know is that CO2 is critical for life on Earth.