Last semester I took a course called “Environmental Preservation and Improvement”, an upper-level seminar where every week students gave presentations on current environmental topics. It was an awesome class, and it excited me so much that I got a little over-ambitious and said that I would provide a brief recap of the presentations given every week. Unfortunately, real life interfered and I only managed to summarize the first presentation about geoengineering and then one of my own presentations on colony collapse disorder.
In the course of that research, I basically came to the conclusion that the culprit at the bottom of all these interacting factors is the use of systemic pesticides, specifically neonicotinoids, on the crops honeybees pollinate (refer to the older post for details).
That was back in October. Almost six months later and the New York Times recently came out with this article and corresponding video (below), which says, in so many words, that growing evidence is pointing to systemic pesticides as the primary cause in colony collapse disorder.
Was I the first person to make this connection? Of course not. Nor has it been determined what exactly is causing CCD. But it’s always rewarding and exciting to see work that I’ve done in class being discussed out in the real world, and it only gets me more psyched to continue learning.
This semester I was enrolled in the Intro to GIS class at Tufts, the first time it was offerred to the undergraduate population. What is GIS, you may ask? GIS stands for Geographical Information System, which allows one to question, interpret, analyze, and understand data and relationships in a visual or spatial manner. More simply, GIS allows one to create maps and analyze trends on a spatial scale. For example it can be as simple as mapping the peaks hiked in New Hampshire (figure 1 in gallery), or as complicated as determining the best location for a hydroelectric dam.
During the semester we were given multiple assignments that were designed to teach us different skills in ArcMap (a GIS program), including using vector and raster data, suitability analysis, interpolation, using census data, and much more. The semester culminated in a self-designed final project that really forced us to consider what problems needed to be solved, how to solve them, and how to work around the different obstacles that arose. While frustrating and sometimes extremely time-consuming, learning to use ArcMap is a skill I am very grateful to have developed.
I’ve included the maps from my assignments below, as well as my final project and poster (Designing a poster is way more difficult than one would think). Below is the introduction to my final project:
Recent developments in the availability of fossil fuels have led researchers and scientists to explore new methods of extracting natural gas from the earth. One of these new techniques is hydraulic fracturing (fracking), where large quantities of water, sand, and chemicals are pumped into horizontal wells to open up cracks in the earth and extract the gas. This technique now allows companies to access gas reserves that were previously inaccessible. Some of the richest resources for fracking exist in the Marcellus Shale formation, which covers most of western Pennsylvania. As of 2010, the Marcellus Shale portion of Pennsylvania had 71,000 active gas wells, with projections of over 60,000 wells being built in the next 30 years. The rapid expansion of fracking has faced strong opposition for multiple reasons, including the possibility of contaminating groundwater or surface water with methane and radioactive wastewater. My goal was to determine areas that would be particularly vulnerable to this type of contamination, specifically places of high human population. I focused on Allegheny County in Pennsylvania because of it’s location within the Marcellus Shale formation andbecause it is the second most populous county in the state.
With this in mind, my project involved a vulnerability analysis, which can also be thought of as a reverse suitability analysis. The objective was to determine areas where fracking sites were most likely to contaminate water sources close to large population centers. To do this, several factors were considered including population, water bodies (lakes and rivers), reservoirs, fracking wells, and public water sources such as groundwater withdrawal. Each variable was given a ranking or score and I used the buffer tool to create and find the areas of overlap between the variables. By calculating which areas had the highest total score based on the score of each variable, I was able to show the most at risk areas for water contamination given these constraints.
Unless you’ve lived under a rock for the past 5 or 6 years (if you have, all the power to you) you have probably heard about how all the honey bees in the U.S have been mysteriously disappearing. Well my partner and I decided to investigate this phenomenon know as Colony Collapse Disorder and try to synthesize the current state of the research surrounding this strange occurrence.
First let’s start with the importance of the Western Honey Bee. It is estimated that 30% of the human diet is credited to the pollination services provided by honey bees. Additionally, in the U.S alone, managed honey bee colonies are the center of a 15 billion dollar economy! And lastly, the honey bee is widely regarded as a general indicator of ecosystem and environmental health.
However, in the past 60 years, the U.S has experienced a steady decline in pollinator populations, with losses of over 3 million colonies (more than 50% of the total population). In the past 5 or 6 years, beekeepers and scientists have begun to see particularly heavy losses in the winter, with colonies virtually disappearing over night. Colony collapse disorder, as it is now known, is made up of the following symptoms:
- An almost complete loss of adult worker bees, with no dead bees found near the hive
- A healthy queen bee and a a disproportionately young workforce
- The remaining bees reluctance to consume ample food stores
- Upon total collapse, a reluctance of neighboring colonies to raid food stores
We investigated the potential for multiple factors to be working together to create these massive die-offs, as the research has been unable to find a clear culprit. The first factor discussed is the usage of systemic pesticides. Systemic pesticides spread throughout all the tissues of a plant, including the nectar and pollen. This means that adult forager bees are receiving direct exposure to the pesticides, and that entire colonies are experiencing indirect exposure when the foragers return. Systemic pesticides are known as neonicotinoids, which have been shown to have significant effects on the central nervous system.
A study by Pettis et al. demonstrated that honey bees exposed to a systemic pesticide known as imidacloprid were significantly more susceptible to infection from the gut pathogen Nosema (figure 1). A second study by Henry et al. showed that exposure to systemic pesticides decreased foraging success in honey bees. The bees were fitted with radar tagging devices to track their position (figure 2). The bees experienced significant “homing failure,” with up to 31% of bees exposed to pesticides unable to find their way back to hive after foraging. Mortality due to homing failure was even higher when the bees were unfamiliar with their foraging area, as one would expect. Here we can see how just 1 factor, pesticides, is able to have multiple effects on bee health and how these factors could interact to weaken colonies.
The missing pieces, as we saw it, came from 2 studies by Mayack and Naug. The first study demonstrated that bees infected with the parasite Nosema (from the 1st experiment) are experiencing elevated hunger levels as a result of energetic stress (figure 3). The bees suffer from energetic stress for two reasons. First, Nosema is parasitic; it robs the bees of carbohydrates, proteins, and other nutrients that it would normally receive while foraging. Second, the bee is now forced to launch an immunological attack, which uses more energy. In their experiment, Mayack and Naug show that infected honey bees experience higher hunger levels and higher rates of mortality due to starvation. Honey bees are clearly trying to compensate for this nutritional stress. A key fact here is that in this experiment the bees were not required to fly in order to reach their food, and were kept at an ideal temperature. This means that neither the high energy cost of flying, nor the cost of thermoregulation were taken into account here. This signifies that in a real world situation the energetic stress experience by bees is probably much greater. It is also important to note here that the foraging behavior of bees is determined by the nutritional stress of the individual and not of the hive, so an infected bee would feel the urge to forage even if the hive has plenty of food.
The last part of this puzzle comes from what could be considered more of a series of observations than an experiment conducted by Naug. Essentially, Naug shows that natural bee habitat has been generally declining while urban development and monocropping have been increasing over the past 40 years, matching the decline in pollinators (figure 4). The consequences of these land changes are threefold: bees must travel further to reach foraging areas, the suitable foraging areas are now smaller, and therefore there is higher competition for resources.
When we look at all of these factors working together, the end result looks something like this: energy-deficient honey bees are travelling further and facing more risks and higher levels of competition in order to satisfy unnatural levels of hunger. This in turn wastes more energy, further weakening the nutrition-starved bees who are now having difficulty finding their way home.
If you ask me, that sounds like a pretty good way to have all your worker bees vanish without a trace.
Note: this is a very condensed, simplified version of a 40 minute presentation. If you would like more information and/or a works cited, please contact me.
What is geoengineering you might ask? Well depends who you’re asking. Some call it climate intervention, others remediation. The bottom line, however, is that geoengineering is deliberate human intervention on a global scale to mitigate the effects of climate change. There are multiple techniques of geoengineering, I will cover two here.
First is Carbon Dioxide Removal (CDR), which is pretty much exactly what it sounds like. The strategy is to remove CO2 from the atmosphere and store it somewhere else. This is called sequestering. There are a couple options when it comes to CDR. The most logical and low-risk is to make a fundamental change in land use management. Trees naturally remove CO2 from the atmosphere, so if communities around the world gave preference to trees over development, we could take back some of the carbon dioxide we’ve released into the atmosphere. Sadly, it’s not that simple. First of all, trees take a long time to grow, and people are impatient. Additionally, in capitalistic societies (like the U.S) trees don’t make you rich, building more factories and developing real estate does.
The next type of CDR is air capture. This is the idea that we could build machines that extract CO2 from the atmosphere and then store it. Direct air capture has been proven to work effectively, taking in “dirty” air and pumping out “clean” air, but once again the story isn’t so simple. These machines would have to be huge. Like, ridiculously huge and unsightly (see below). Not to mention that they will use equally large amounts of energy, contributing to the related problem of energy usage.
There are many other suggested techniques of CDR, including biochar, and carbon capture storage, but I’m trying to keep this compact.
After CDR there is Ocean Iron Fertilization, an interesting idea first formed by John Martin that takes advantage of the natural system of the biological pump found in our oceans. The strategy is as follows: The ocean is filled with phytoplankton, which are tiny marine organisms that use photosynthesis to take in CO2 from the water (which is absorbed from the air) and break it down. The ability of phytoplankton to grow larger and break down CO2 is limited by iron, a mineral that arrives to the ocean as fine dust particles. Studies of arctic ice cores have shown that there is an inverse relationship between iron dust and CO2 in the atmosphere, leading scientists to believe that when there is more iron abundant in the oceans, phytoplankton bloom mightily and remove a fair amount of CO2 from the global atmosphere. So, scientists have gotten it in their head that if they dumped a whole bunch of iron in the oceans, they could trigger phytoplankton growth and subsequent CO2 removal. Seem to simple to be true? That’s cause it is. A few of these experiments have been carried out with very limited success. Plus there’s the issue that iron doesn’t just grow on trees, nor is it cheap to ship it to the middle of the ocean And thirdly, although the ocean is the largest sink of Carbon on our planet, it eventually releases it back into the atmosphere, making ocean fertilization a temporary fix.
There are other geoengineering techniques such as solar radiation management and stratospheric sulfate aerosols. All of these actions have their own benefits and each have serious drawbacks and potential consequences attached to them. I’ve mentioned some here, but this is a surface explanation, there are components which I have excluded for simplicity and brevity. In my opinion, these techniques should be approached with serious caution, because they are all reactionary, not preventative. If we allow the general public to believe that these technologies will solve the problems currently affecting Earth, it will be tragic. We need to continue to develop ideas to stop global warming in the first place, and maybe then geoengineering can be used as a complement. It is also important to note that these technologies would not spring up overnight – they require extensive planning, funds, and cooperation from many disciplines and governing bodies. Lastly, I just do not like the idea of man trying to tinker with global forces. When will we learn that the forces of nature are much stronger than us?
I’m currently taking a seminar class at Tufts called Environmental Preservation and Improvement taught by Professor George Ellmore. The class is unique in that we only meet once a week (albeit for 2.5 hours) and every week there are one or two student presentations on an environmental topic. As a student you present twice a semester, and when you’re not presenting you’re reading an article regarding that week’s presentation and engaging in discussion about the topic. So far I’m really enjoying the class because every week I come away with a plethora of knowledge about a new topic and the confidence to talk about it. For me, it’s a much more effective learning technique than sitting in a classroom trying to stay awake through a powerpoint lecture. To further my learning experience, I’m going to try to post a summary of as many of the topics as possible, so even if no one else reads it at least I’m able to reinforce what I’ve learned. So first up is the topic of geoengineering, which I’ll post shortly.