Carbon Dioxide

*Before you read this blog article, please pay special attention to the links I've added. Some of them are graphics which I do not have the rights to that will add greatly to your understanding of this concept.

I've been a bit stuck for the past couple of weeks. While my fingers go numb from the cold pulling in water samples on a windy bay and my mind begins to spaz as I do the mental somersaults of calculating radiocarbon, my heart sinks to the pit of my stomach every time I see another article about decreasing scientific funding, about Scott Pruitt's latest opinion on carbon dioxide, and as school teachers receive books in the mail riddled with erroneous information on "why scientists are divided on climate change." After I finish my water samples, I go to class and I learn about plummeting oxygen in the ocean. I read articles about the Great Barrier Reef dying. I am bombarded by threats to the EPA and NOAA. Every day, the folds of the internet and the current political climate take turns both whispering and shouting. Is it the fate of this group of hard working passionate people to be ignored? Is all of our understanding of the planet to be thrown away because we don't like the picture we are seeing?

An incredibly warm day in February on the Narragansett Bay

In the past few weeks, I've wanted to talk about many ocean problems. I wanted to talk about the reefs around the world that are dying at alarming rates. I wanted to talk about how there is less oxygen in the ocean than before, which is bad for species that rely on oxygen. I wanted to talk about how the ocean is getting more acidic, and this hurts species that have hard shells, like shellfish. I wanted to talk about sea star wasting syndrome, a terrible disease that is linked to warm ocean temperatures. There is one thing all of these issues have in common: carbon dioxide. Carbon dioxide is natural and necessary, but it is also linked to a huge number of the ocean's problems. In order to fully understand it, we have to go to the source.
So let's start with how carbon dioxide fits into nature. In a previous blog article, I talked about how plants and phytoplankton take up carbon dioxide in order to go through photosynthesis, releasing oxygen. When we breathe out, we do the reverse reaction, called respiration, and we exhale carbon dioxide. This carbon dioxide that we exhale is the reason people with panic attacks will breath in and out of a paper bag; it forces you to breath in the carbon dioxide you already exhaled (this is all related to the level of acidity in your body. I won't get into it, but you can learn more about it here).

Photosynthesis

Breathing, however, isn't the only way that humans release carbon dioxide. When we burn coal, petroleum, or natural gas (considered to be the cleanest of the three options), carbon dioxide is released into the air. Natural levels of carbon dioxide in the atmosphere help to keep the planet warm enough for life by working as an insulator of the sun's energy. This is because energy from the sun, like all energy, travels in waves. You see this in action every day as you observe different colors, which is a result of different wavelengths of light (this is the distance between two peaks in the waves). The energy of the sun enters through the carbon dioxide in the Earth's atmosphere at a particular wavelength that can easily pass through the gas. After the energy hits the surface of the Earth, it is reflected back at the atmosphere, but because some of the energy has been lost, it travels at a different wavelength which is not as good at getting through a layer of carbon dioxide. This means some of the sun's energy is reflected back to stay on Earth. The more carbon dioxide there is, the more energy gets reflected back, and the warmer the earth gets. If this all seems rather abstract, think of carbon dioxide as a blanket, keeping Earth nice and warm. The thicker the blanket, the more heat gets trapped.

Scientists have had some inkling that humans may be impacting the climate since about 1890, but it's become more clear as data supporting this idea has continued to build. There is scientific consensus that the Earth is warming, and according to NASA, the most likely cause of climate change is human's release of carbon dioxide. In addition, a recently published open access paper by John Cook and his colleagues found that 97% of scientists agree that the most likely cause of climate change is human activity (if you are interested in investigating for yourself, you can find the paper here). Just take a look: this model from Bloomberg took NASA's data on a number of factors that scientists have speculated cause climate change and compared their levels to global temperatures. Greenhouse gases, which include carbon dioxide, were the closest match by far.
Earth's climate has changed before. There used to be grape vines in Canada, for example, when the vikings showed up. Before humans started releasing massive amounts of carbon dioxide, the earth was actually cooling. However, temperature change on a global scale, without man's assistance, does not happen at the rate it is currently happening. Have we been measuring global temperatures since the times of King Tut? No. However, we can figure calculate past temperatures because of the hard work of countless dedicated scientists who have looked at ice cores, or long tubular samples of ice from the Arctic. When looking at the stump of a tree, you can count the rings of a tree to know its age and you can look at the distance between the rings to tell how much it has rained. In a similar way, scientists have developed ways to estimate the temperature of the planet from layers of ice, as well as extracting samples of the gases that were trapped in the ice at the time it froze. All of this has led to the conclusion that the earth is warming at a rate which has not been seen before. A brilliant artist, xkcd, who frequently does science related pieces, put together a brilliant timeline of Earth's global temperature for reference, and I highly recommend you check it out.
So the Earth is warming, and there are more greenhouse gases than before. This is a global problem, not just us. Why should you care? The US has a disproportionate impact on carbon emissions. Based on 2011 measurements, while China releases the most carbon in total, the US releases the most carbon per capita, meaning the average US citizen releases more carbon than anyone else from any country in the world. This is is large part due to our very comfortable, tech heavy lifestyles. We also tend to rely on our own personalized modes of transportation as opposed to public transportation, and most of us have diets with a lot of meat and get exotic foods shipped from far away. Scientists frequently refer to the amount of carbon we release as individuals as our carbon footprints, and as Americans, ours are massive. However, there are many ways that we can try to lower our carbon footprint and therefore be better neighbors, such as carpooling, taking faster showers, turning the heat in your house down a couple of degrees, buying more fuel efficient cars, or even eating less meat (being vegetarian is one of the easiest ways to lower your carbon footprint dramatically).
In the coming weeks, I will be touching on the many ways that carbon dioxide has an impact on the ocean, but for now, what I want you to remember is:

1. Carbon dioxide is a natural and essential gas on planet Earth.
2. Human emissions of carbon dioxide from burning coal, petroleum, and natural gas are the largest on record this year, and the US contributes a disproportionate amount.
3. Greenhouse gases, including carbon dioxide, are believed to be the leading cause of climate change on Earth. While climate change has happened before, it has not occurred at this rate.
4. Carbon dioxide has a huge impact on the oceans, not only as they warm, but in a number of ways that I will discuss later.

This blog article has been a bit ocean light, but that's only because I want to get into ocean specifics in more detail, and in order to do that, it is important to understand where these ocean problems are coming from. The scientific community has been warning about the dangers of rising carbon emissions for years. If by some trick of destiny the thousands of them who have come to this conclusion turn out to be wrong, limiting carbon emissions will only keep the earth cleaner and will help with other problems like ocean acidification (more on that later). However, if the scientific community, a group of people who have nothing to gain from sounding the alarm, is right, and we turn our backs on this now, we will create a problem that will have sweeping ramifications, on land and sea.