by Alyssa Leavy | Zoom Out Mycology
How glaciers serve as our main defense against one of the largest releases of greenhouse gases in history.
Glaciers are an essential part of our planet’s landscape and climate. Although they seem remote, their presence is felt in every corner of the globe. Ten percent of land is covered with glacial ice, adding up to over 5.8 million square miles (NSIDC)(2). Glaciers contain so much water that if they were all to melt the sea level would rise 230 feet (NSIDC)(2). To put this in perspective, sea levels are expected to rise about 3 feet by 2070. Taking into account that many delta cities are concurrently losing their foundation sediment and our planet’s growing population, that 3 foot rise in sea level will put about 150 million people at risk of flooding in coastal areas (The World in 2050)(3). Another consideration is that as glaciers melt, we will also lose our fresh water reserve, since glaciers store about 75 percent of the world's fresh water (NSIDC)(2).
Glaciers also influence climate patterns and reflect the sun's rays, protecting against intensifying natural disasters and rising global temperatures. That’s enough for me to change my habits, but if you’re not convinced that we need to conserve these icy habitats, then read on!
Glaciers are integral to human survival in many ways and scientists are discovering another critical protection that dates back millions of years. As the Earth has cycled through warm and cold periods, organic matter has flourished, died and been encased in ice, unable to decompose. This makes glaciers one of the largest carbon sinks on the planet. If global warming trends continue, all of that organic carbon could be released as glaciers melt, spewing carbon dioxide and methane into the atmosphere. It’s a startling thought to say the least, but before we can understand the magnitude of this issue, we need a little history lesson on the holocene.
The Horizon of the Holocene
The Earth is in its sixth ice age, named the Quaternary glaciation, which started about 34 million years ago (Wikipedia)(4). Within an ice age, there are periods of extreme cold, glacial periods, and periods of relatively warmer weather, interglacial periods. When increased temperatures caused glaciers to recede, the Wisconsin glacial period (aka “The Ice Age”) ended and humans began enjoying a much more temperate climate. This interglacial period that started 11,700 years ago is known as the Holocene. The graph below shows how antarctic temperatures have fluctuated over the past 800,000 years, with the latest peak representing the Holocene era.
We can also see the relationship between temperature and carbon dioxide levels. In the past, carbon dioxide concentrations have changed naturally, with no human influence. However, considering the affect the industrial revolution has had on atmospheric greenhouse gases, some scientists are pushing to use a new term, Anthropocene, to acknowledge the impact of human behavior on our planet (The Guardian)(6). On the graph above it may not be clear the connection between human influence and global warming, but it is clear that carbon dioxide is linked to global temperatures.
So where do present day humans fit into the epoch of Earth? I’ve heard some very intelligent people (and a stable genius) claim that global warming is nothing more than a hoax. Their logic is that our planet goes through warming and cooling cycles (true); that the warmer period we’re currently in wasn’t started by humans (true); and that the world will naturally shift back into a glacial period in the future (also true). If you don’t take timing into account this is a decently convincing argument; however, the next shift into an ice age could be 2,000 years from now (Science)(7). In the meantime, humans have plenty of opportunity to influence global temperature, for better or worse.
On a macroscale (hundreds of thousands of years), where data is based on inference, we see the direct link between atmospheric carbon dioxide and temperature (Scientific American)(8). On a microscale (one hundred years), where our data is based on observation, that conclusion is even more apparent. Below is a graph that illustrates the relationship between rising carbon dioxide levels and global temperatures during the Industrial Revolution.
So it’s clear that carbon dioxide is linked to global warming and it’s clear that the recent spike in carbon dioxide concentration was caused by human activity. The effect is that we are creating an environment that is untenable for our beloved glaciers, and ourselves. Our connection to glaciers is more than just temperature and climate regulation though. Some people are closely tied to these monumental masses.
Permafrost: The Perennial Pillar
Humans live in all climates and temperatures; the edge of freezing and beyond is no exception. Utilizing various technologies, some cultures have admirably (if not stubbornly) made their homes in some of the harshest places on earth. Igloos and animal-skin garments are carefully crafted to embrace the challenges of arctic temperatures. One nature-defying example of this creativity is the building of seasonal ice roads. In the coldest winter months, ice solidifies to the comparable strength and hardness of concrete. This allows locals to forge roadways to bring crucial supplies to areas that may be nearly inaccessible otherwise. The foundation for the ice roads is permafrost. Permafrost is a mixture of water, organic matter and rocks that is below freezing (the exact temperature varies depending on the composition) for two or more consecutive years (Britannica)(10). In areas of Canada, Russia, and the United States, construction crews rely on permafrost the same way New York City relies on bedrock to support its structures. As global temperatures rise, we start to lose the integrity of these roads, isolating communities and removing a cost-effective way of transporting goods and construction materials (The World in 2050)(3). The loss of permafrost isn’t the only concern though - the organic matter trapped in the ice is the greatest threat we face in the fight against global warming.
Catastrophe: Carbon Cut Loose
Carbon dioxide (CO2) and methane (CH4) are greenhouse gases that contain carbon. Although carbon dioxide is a serious concern, it’s not even the most potent greenhouse gas. In terms of global warming potential (GWP), methane is estimated to be 34 times more powerful than carbon dioxide over a one hundred year period (Project Drawdown)(12). These gases are produced in a variety of ways, but the focus of this post is microbial digestion. As permafrost starts to thaw, trapped organic matter is exposed. The increased temperatures also create a more viable environment for microbial activity that was previously arrested by freezing temperatures. As this organic matter is broken down, carbon dioxide and methane will be released into the atmosphere. The top most layer that is exposed to oxygen will produce carbon dioxide through aerobic digestion. The trapped matter will undergo anaerobic digestion to produce methane. To appreciate the weight of this concern, it’s essential to assess how much organic carbon is contained in permafrost. The chart below shows a comparison between carbon contained in soil, permafrost, all proven fossil fuel reserves, the atmosphere (atm) currently, before the industrial revolution and after the last ice age, in all living plants, and in annual fossil fuel consumption (and making cement). For reference I also included the Kyoto Protocol reduction, which is 0.2 gigatons of carbon emissions annually.
As you can see, melting permafrost has the potential to create more greenhouse gases than burning all of the remaining fossil fuel reserves on the planet. The only carbon sink that is substantial enough to counteract this calamity is our soil, which contains 1,550 gigatons of organic carbon (the rest is inorganic) (Nature) (13). Permafrost has been protecting us for tens of thousands of years from a cataclysmic release of greenhouse gases. That protection is starting to disappear as permafrost thaws and creates a warm, moist environment for microbes to digest organic matter that would otherwise be kept in check.
Balance: Broaching the Borderline
Although this ticking time bomb seems mission critical, the truth is that this concern is a relatively new discovery. There might be decades of research needed before scientists truly understand the exact threat posed. There are many factors to consider.
The increasing temperatures will not only be ideal for microbial activity, but for vegetation growth. The rich soil in the permafrost, along with the water provided by melting ice, will create a desirable climate for plants and trees to grow. These carbon sinks will consume carbon dioxide released from the microbial activity (The World in 2050)(3). However, it is pertinent to note that they will only act sequester carbon in the form of carbon dioxide, not methane, the more potent of the two gases.
This is where things get interesting and unfortunately current predictive models haven’t caught up yet. If microbes produce more carbon dioxide than fledgling foliage can utilize, there will be a net positive release of CO2. Many factors need to be considered, including the rate of carbon dioxide formation versus methane formation. This issue is especially critical because we do not have a means to harness this potential methane release.
These areas are currently sparsely populated, but as temperatures rise, ice melts, and vegetation grows, people will be drawn to these regions. The lifestyle of these migrants will have its own impact. If inhabitants cultivate gardens, use renewable energy and eat plant-based diets, they could have little to no effect on greenhouse gas emissions. In fact, if newcomers live a sustainable lifestyle, they may even be able to achieve a net negative release of emissions. However, if migrants continue with current trends of energy use, cut down the forests, and bring in a large population of methane-producing cattle, they’ll just be compounding the problem.
Steps to Sustainability
So how do we reduce our carbon footprint now before we sacrifice our precious permafrost? I would highly recommend reading Project Drawdown. The book is a resourceful guide to how we can make the biggest dent in our greenhouse gas gluttony. It’s also how we prioritize which sustainability solutions to implement at Zoom Out Mycology! Among those recommendations are proper disposal of refrigerants, providing a proper education for girls, consuming a plant-based diet, and reducing our reliance on fossil fuels. To learn more about the positive impact you can have on our planet contact our founder, Bashira Muhammad, at firstname.lastname@example.org. If you’re in Southern Oregon or New Jersey, she can help you replenish your soil, revive your compost, and recommend fungi to incorporate into your crops and diet. I also encourage you to check out my
previous post about how to minimize organic waste in your kitchen.
What are your favorite ways to reduce your footprint? We’d love to hear your feedback below!
Zoom Out Mycology’s Environmental Awareness blog strives to explain and expose environmental topics and concerns to a wide audience. Our team consists of a diverse group of scientists, policy experts, and engineers that help describe the science behind environmental issues that you see in the news and experience in your daily life. We hope that this knowledge will help all of our readers embrace a healthy and sustainable lifestyle! If you are interested in being a guest contributor, please email us at: email@example.com