According to a 2013 study conducted by international research and data analytic group YouGov, autumn is the favorite season among American citizens.

Although northwestern Pennsylvania has already passed its peak of fall foliage, according to the PA Department of Conservation and Natural Resources, a variety of colors can still be seen around Allegheny’s campus.

While some people may believe that the changing color of the leaves is a signal of the tree dying, Matthew Venesky, professor of biology, explained that this notion is far from the truth.

“(This is) absolutely false,” Venesky said. “If the trees were dying they would be falling over.”

Professor Venesky currently teaches about investigative approaches in biology and physiological ecology. He amended that while the tree itself is not dying, it is losing part of itself.

In response to the shortening days and lack of light, trees sacrifice their own chlorophyll. Chlorophyll is the pigment that makes leaves green. Trees use chlorophyll in combination with sunlight and carbon dioxide for a process called photosynthesis. Photosynthesis is the process by which plants make their own food for energy.

“Trees make this decision,” Venesky said. “It’s a cost-benefit decision, and it costs too much money to continue to make chlorophyll to food. So what they do is start to break down chlorophyll, and when the chlorophyll leaves the trees, a bunch of different colors and pigments are left and those are what make us see the really pretty oranges, yellows and reds.”

Venesky provided an analogy to better explain the process.

“I love to eat food, and I love to eat tacos and burritos,” Venesky said. “Those are my favorite types of foods. My (favorite) place that I like to go to is Chipotle. There’s a little place in town that serves Mexican food and I don’t like it a ton. I’m not gonna name it … but I don’t like them nearly as much as Chipotle. So the cost benefit analysis for me is do I spend the time, money and gas to drive to Erie to get Chipotle, or do i just settle for the less desirable resource in town which is going to be the local restaurant.”

In terms of trees, Venesky explained that light is their burrito. All types of organisms make these trade-offs, whether conscious or unconscious, he explained.

“The veins that carry fluids into and out of the leaf gradually close off as a layer of cells forms at the base of each leaf,” according to a USDA United States Forest Service webpage. “These clogged veins trap sugars in the leaf and promote production of anthocyanin. Once this separation layer is complete and the connecting tissues are sealed off, the leaf is ready to fall,”

Anthocyanin is one of the compounds that causes the color changes, and causes color in things like blueberries and plums, according to the USDA website.

Venesky also discussed the ramifications of climate change on this season. When seasons shift and the weather becomes warmer, this throws some processes off track that are not thought about.

Professor Venesky spoke about the small streams that harbor many different types of organisms that rely on the leaves that fall into them. “If we are seeing a shift in any event such as climate change, it is going to throw off all these different interactions for organisms in streams and outside of them that depend on the energy inputs from leaves or anything like that.” This then affects the cycle of that ecosystem.

“We would call that a cascading effect,” Venesky said. This type of interaction is more commonly referred to as the butterfly effect in pop culture.

A “Yale Ask Sarah” thread talks about the fall season as well and how it has been delayed. This thread calls for more research on how climate change has affected fall.  It compares the season to Vivaldi’s “Autumn” from “The Four Seasons,” remarking that the addition of jazz melodies to the classic edition is representative of how fall may change in the future.

Another thing that may cause issues for Earth during fall is the way people discard their fallen leaves. Instead of disposing leaves in the trash system, or burning them, Venesky suggests that composting leaves is beneficial to the environment.

“If you dispose of leaves in other methods, say, landfills, that will have a pretty negative effect,” Venesky said. “Because of the way decomposition happens underground, it’s actually probably going to increase greenhouse gases.”