Breath of Clarity

Ecology Discussion #5: B

The Planet Earth video illustrates, insofar as human population increases with continued resource consumption rates and methods, pollution problems will persist (BBC 2013). Further, human activities have at least doubled the transfer of nitrogen from the atmosphere into the land-based biological nitrogen cycle, and the greatest human-driven increases in global nitrogen supplies are linked to activities intended to boost food production (Vitousek 1997). There have been massive losses of soil nutrients such as calcium and potassium that are essential for long-term soil fertility. Moreover, ecological conditions are also declining due to the increase in ammonia (NH3) and the ongoing biomagnification of mercury in food webs (Vitousek 1997). The tipping point happens at the moment an ecosystem shifts to a new state or condition in a rapid, often irreversible, transformation. The consequences of these changes may be difficult or impossible to reverse as impacts cascade throughout affected ecosystems. In formerly species-rich heathlands across Western Europe, human-driven nitrogen deposition has been blamed for great losses of biodiversity (Fen et al. 2011). Also, eutrophication is linked to losses of diversity, both in the sea floor community —including seaweeds, seagrasses, corals and among plank-tonic organisms (Fen et al. 2011). Fish populations have been reduced or eliminated in many acidified lakes across Scandinavia, Canada, and northeastern United States (Fen et al. 2011). Caused changes in the plant and animal life, as well as ecological processes of estuarine and nearshore ecosystems contributed to long-term declines in coastal marine fisheries (Fen et al. 2011). Considering already lost biodiversity, the trend in ecosystem damage is irreversible.

Repayment of this “carbon debt” can occur once the net GHG emissions from production and combustion of the biofuels drop below the GHG emissions of the fossil fuel being replaced (Duke et al. 2013). Conversion of native lands (tropical rainforest, peatland rainforest, and grasslands) is estimated to incur large carbon debts that would take decades to centuries to pay off, depending on the crop and the type of land being converted. For example, conversion of grasslands in the central U.S. to production of corn for ethanol would create a carbon debt that would take 93 years to repay (Duke et al. 2013). The estimated payback time for the carbon debt associated with converting Conservation Reserve Program land in Michigan to biofuels under five different scenarios ranged from 29 years for corn-soybean rotations managed without tillage to 123 years for continuous corn conventionally tilled (Duke et al. 2013). While certain strategy, such as installing wind turbines, can be implemented in attempt to reverse the current trend in ecosystem damage, there are accompanying downsides, such as killing of many species of bird, which cannot be undone (Alison et al. 2019).


Allison, Taber D., Jay E. Diffendorfer, Erin F. Baerwald, Julier A. Beston, David Drake, Amanda M. Hale, Chris D. Hein, Manuela M. Huso, Scott R. Loss, Jeffrey E. Lovich, M.Dale Strickland, Kathryn A. Williams, and Virginia L. Winder. 2019. “Impacts to Wildlife of Wind Energy Siting in the United States.” Issues in Ecology 21:1-23.

BBC. 2013. “Planet Earth: The Effects of Humankind”. Accessed Feb 3, 2020

Duke, Clifford S., Richard V. Pouyat, G. Phillip Robertson, and William J. Parton. 2013. “Ecological Dimensions of Biofuels.” Issues in Ecology 17:1-17.

Fenn, Mark E., Kathleen F. Lambert, Tamara F. Blett, Douglas A. Burns, Linda H. Pardo, Gary M. Lovett, Richard A. Haeuber, David C. Evers, Charles T. Driscoll, and Dean S. Jeffries. 2011. “Setting Limits: Using Air Pollution Thresholds to Protect and Restore U.S. Ecosystems.” Issues in Ecology 14:1-21.

Vitousek, Peter M., John Aber, Robert W. Howarth, Gene E. Likens, Pamela A. Matson, David W. Schindler, William H. Schlesinger, and G. David Tilman. 1997. “Human Alteration of the Global Nitrogen Cycle: Causes and Consequences.” Issues in Ecology 1:1-16.

Comment by Ed Piersa:

Mary –

I agree that there are disadvantages to wind turbines, including the killing of birds as you described above. Furthermore, the technology is imperfect. As Sachs (2015, 427) explains, “Winds also fluctuate unpredictably. Even very windy locations occasionally experience hours or days of becalmed conditions with little power generation, and in many places winds are highly seasonal.”

Despite such disadvantages, I contend that the benefits of renewable energy technologies far outweigh the costs for ecosystems. For instance, fossil fuels are finite whereas renewable energy is potentially unlimited. Moreover, these technologies would reduce greenhouse gas emissions which will do far greater good for ecosystems than anything else. As Seyboth et al. (2012, 830) explain, the annual greenhouse gas reduction potential of all renewable energy technologies “in 2050 reaches from 4.2 Gt CO2/yr.… to 35.3 Gt CO2 /yr.” Additionally, these “analyzed scenarios would have a cumulative reduction potential (2010 to 2050) in the medium case approach of between 244 Gt CO2… and 490 Gt CO2” (Seyboth et al. 2012, 830).


Sachs, Jeffrey D. 2015. The Age of Sustainable Development. New York: Columbia University Press.

Seyboth, Kristin, Patrick Matschoss, Susanne Kadner, Timm Zwickel, Patrick Eickemeier, Gerrit Hansen, Steffen Schlömer, and Christoph von Stechow. 2012. Renewable Energy Sources and Climate Change Mitigation. New York: Cambridge University Press.

Comment by Professor Fenton Kay:

Very well stated post, Mary. It seems like we may have to tolerate bird losses in order to save humanity. Wind power does cause increased mortality in some birds and migrating bats. There appear to be some technological fixes that will reduce, but not eliminate, the mortality. I agree that much or perhaps all of what we have done already is irreversible. Can we successfully adapt our actions and become as resilient as the ecosystems we are plundering? If we cant’ reverse the damage, do you think there are avenues that will allow us to adapt?



My Response to Professor Fenton Kay:

Hi Fenton,

I am interested in the specific technological fixes that are going to reduce bird mortality amidst wind mills. Kevin Martin, who runs Alta Environmental Services, described a system based on two principles: 1) Know if a bird is coming 2) Make sure blades aren’t spinning when it arrives (Bennet 2018). His research is specifically aimed at preserving the California Condor. Awesome question. I see the potential for any species to adapt. A key step to the human species doing so is reducing its population. Considering, for example, water is already a depleting resource, even the human species changing its ways is going to have to encompass decreased use of essential substances. It would be a solution allowing the damage to be mitigated even though it is not reversible.


Bennet, Molly. 2018. “How New Technology Is Making Wind Farms Safer for Birds”. Audubon. Accessed October 15.

Response by Professor Fenton Kay:

Mary, I recently read a short article that says that there is some promise in painting one of the rotors a dark color (black). Initial studies suggest that doing so reduced mortality significantly. However, the article says that more study in more places and with more species is needed. No mention of bats – but probably doesn’t work for them. bright lights, maybe?



My Response to Professor Fenton Kay:

Hi Fenton,

Good point about the bright lights being a viable possibility. A 2010 study suggested that purple wind turbines would in theory cause fewer bird strikes than the typical white ones because white blades attract insects, and insects attract foraging birds (Bryce 2016). In 2012 the National Science Foundation awarded a grant to researchers who showed that UV lighting could be used to deter bats and birds from wind farm sites (Bryce 2016). Also, inventors are increasingly looking into vertical axis turbines. The blades rotate around a central spire, enabling many to fit within the space together. These vertical shapes might be less detrimental to birds (Bryce 2016). With all that being said, however, the technology has not improved enough to significantly mitigate the problem in the present day. It is interesting to look at how policy is going to drive further innovation. The Bald and Golden Eagle Protection Act recommends companies consider where to place the turbines as a way to limit bird deaths (Bryce 2016). The Migratory Bird Treaty Act declares it is illegal to kill any bird protected by the act —even if the death is “incidental,” meaning it occurs unintentionally on the part of the wind farm (Bryce 2016).


Bryce, Emma. 2016. “Will Wind Turbines Ever Be Safe For Birds?”. Audubon. Accessed October 18.

Comment #2:

Original Post by Mariah Rivera:

Hello Amanda and Professor Kay,

I actually did my senior thesis on recycling plastics and am actually in the works of getting it published with two of my other partners. Recycling all of the plastics in the world is not necessarily a viable option as in how recycling is so inefficient as we have it now in that only less than 10% of all plastics actually get recycled because there are so many different types with different monomers and polymers that make up the plastics. Another thought is that there are over a billion micro plastics in the oceans now in almost every crevasse of the sea that we would never be able to fully detect.

Another thought to keep in mind when comparing carbon emissions by year is that looking at emissions during the summer is not the best way to calculate emissions as during the summer GHG are at their lowest and during the winter GHG are at the highest. One way I was taught during my undergrad was to take a mean of the two and that is what your yearly average will be rather than detecting it by month.

My Response:

Hi Mariah,

It is interesting and unique to consider the inefficiency of recycling. With the renewable energy boom, people are starting to consider how solar panel systems are going to be recycled. However, a major problem illustrated in your post is the different monomers and polymers involved. There are various types of panels including monocrystalline, polycrystalline and silicon. Also, the billion micro plastics in the oceans are now impacting biodiversity which is irreversible. Although new species will emerge with traits conducive to the evolving environment, the damages cannot be reversed to its original state.