How Climate Change Can Bring Evolutionary Changes Upon the Natural World and Its Effects, Including a Possible Extinction Written by Toran Ham

The world is changing, literally. Humans have been altering the natural world at an increasing pace year by year. These changes have greatly impacted the Earth’s landscape in a period known as the Anthropocene, or age of the Humans. The largest factor that causes these environmental differences is known as climate change. This can be caused by a multitude of processes, but the largest being the burning of fossil fuels which releases large amounts of methane and carbon dioxide, which are greenhouse gasses. The rising temperatures due to climate change affect the human body and can change body temperature, metabolism, and brain function. Additionally, other species besides humans are also being affected by habitat loss, environmental changes, and other byproducts of climate change. These changes are happening all at once, which is already presenting possible problems, which can include local extinctions of species to start to occur because of the changing temperatures and other factors due to climate change from human activity. Due to the large effects of climate change on the earth, species living on earth may go through a large evolutionary transformation because of rising temperatures on humans, habitat loss which affects all other species, and possibly an extinction-level event.

Humans Are Experiencing Changes

The rising temperatures due to climate change affects the human body and can change body temperature, metabolism, and brain function. Climate change, also known as global warming, is caused by the rising levels of greenhouse gases, which means that there is less total oxygen in the air. The actual warming part of climate change affects the body and its functions. Another effect of climate change is metabolism which can be affected by temperature. An interview done by The Atlantic said, “Karnauskas is worried that indoor CO₂ levels are getting so high that they are starting to impair human cognition. In other words: Carbon dioxide, the same odorless and invisible gas that causes global warming, may be making us dumber” (Meyer). Humans’ bodies and brains need one thing to develop and function: oxygen. As CO₂ levels rise, there is less net oxygen in the air to allow the body to function. This can impair thoughts and cause dizziness. As this is affecting the brain, it could even affect the rest of the body as most of the functions happen from the brain. Even though this is occurring and could affect everybody on the planet, the amount of greenhouse gas production is still rising.

A study conducted says that “The findings suggest that humans may acclimate to cool temperature by increasing brown fat, which in turn may lead to improvements in glucose metabolism. These changes can be dampened or reversed following exposure to warmer temperatures” (Cool Temperature).

This CT scan (computerized tomography scan) shows that in varying temperatures the amount of brown fat changes.

Because of the warming effects that fossil fuels have on the earth, the body has to change in order to survive. One of the major ways to adapt to the temperature is to change the rate of metabolism. In cooler environments, including polar to temperate regions, the body increases brown fat, which is healthy, and burns calories and yellow fat. In hotter environments, this is reversed and there is a lack of brown fat which means that fat goes away more slowly because the body conserves energy as it is being burned from environmental conditions. This means that it is possible that evolutionary changes are occurring and that humans are more likely to have obesity and diabetes from lower metabolism. Humans are affected by the effects of climate change through temporary and possibly permanent, physical, changes of the body, but other species besides humans are affected too.

Animals are Being THreatened

Other species besides humans are also being affected by habitat loss, environmental changes, and other byproducts of climate change. Not only humans, but animals and many different species are being affected, due to the effects that humans have on the natural world. These effects are occurring more rapidly than ever before for economic purposes.

Many animals are moving to higher elevations and latitudes to escape warming temperatures, but climate change may be happening too quickly for most species to outrun it. In any case, moving is not always a simple solution—entering new territory. could mean encountering more competition for food, or interacting with unfamiliar species (Cho).

Animals are relocating and migrating due to vegetation and food changes in their habitats

As an effect of climate change, animal habitats are affected which can lead the species living there to find a place to relocate to. This affects the species living in the environment, which affects the food chain, which in turn can cause a lack of resources. This can cause death or extinction to small species that need certain conditions to survive. The other way to survive is to adapt to the changing conditions, which some species are trying to do already by “breeding even earlier with the warming climate,” which can cause genetic/evolutionary changes in their offspring, but depending on the species and how fast or how many offspring they produce, the evolution may occur “very fast over a few years” or “or it can be a slower process” over many generations (Pleul). These changes can be as simple as trying to survive the slightly different temperatures that climate change brings. Climate change with its large effects can influence every living thing on the planet and affect them, whether it be from changes of the body or the environment but if it escalates it can even lead to extinction.

Species are Disappearing

Local extinctions of species, such as coral bleachings, are starting to occur because of the changing temperatures and other factors due to climate change from human activity (Cho). If humans and animals become affected on a larger scale than what is currently happening, including adaptations and relocation, it can cause disruption to how animals live which can cause, in the long term, extinction:

Coral becomes white because the colorful algae gets expelled from the coral, due to hot temperatures

Today, extinctions are occurring hundreds of times faster than they would naturally. If all species currently designated as critically endangered, endangered, or vulnerable go extinct in the next century, and if that rate of extinction continues without slowing down, we could approach the level of a mass extinction in as soon as 240 to 540 years (Greshko).

Because the rate of carbon emissions, which fuels climate change, has increased to the greatly, because of the burning of fuels, the amount has quickly increased within the past 60 years to 407.4 ppm (parts per million) which is “100 times faster than previous natural increases” since “last ice age 11,000-17,000 years ago” (Lindsey). Recently, as climate change worsens people don’t seem to think of the effects that it has long term on them and the world. This is already beginning to show as some aquatic and land species’ numbers are already going down. It is even suggested that species are going extinct at a rate of “24 a day” to even “up to 150 species are lost” per day, which is “up to 100 times higher than the background rate” of extinction with little to no human involvement (Pearce). Climate change, unless we do anything about it, would continue to worsen until a possible extinction, but some studies conducted by scientists have different ideas.


Although climate change is a factor that affects species, it will not cause extinctions, but rather the effects that humans have on land, like deforestation. Other than climate change, people have had a large effect on land to make room for expansion and to gather resources, which can be shown as mining or deforestation.

One of the main contributing factors to extinction and endangerment of species is “overexploitation.” This is when people use their resources too much, but in this case, it would be hunting an animal to extinction. Along with this, there is also deforestation which destroys animals’ habitats and forces them to relocate to an area that may not suit their needs (Kluger).

Humans have been changing and taking from the land, which damages animals’ habitats and changing the food chain, which affects biodiversity. People are also hunting the animals to a point where they are going extinct, which also affects the predators of the extinct species which now has no source food. This also causes the food of the now extinct animal to run rampant and overpopulated because there is no predation to keep numbers within a sustainable range. The largest cause of a possible extinction is because of “overexploitation”, where humans damage or exploit species and their wildlife where it permanently damages everything else around them.


Although some people may believe that using animals and their surroundings may be the largest possible cause of extinction, it is actually climate change because of the many adverse effects that it brings and the effects of the natural world that it causes. In contrast to the fact that overexploitation is the main cause of extinction, climate change is the real culprit of biodiversity changes due to the fact that some areas are turning into marshes. This is due to the fact that “salty water,” from oceans, “moves into forested areas, first slowing, and eventually halting, the growth of new trees” (Root). These areas not only include public forests, but even protected areas and reserves which are safeguarded from exploitation of any kind, let alone overexploitation of resources. In turn, these flooded areas are not only turning into marshes and preventing new plant growth, but are also affecting the wildlife that used to live there, even aquatic animals that used to thrive in freshwater streams or other types of forest fauna.

Already sparse forests can flood and turn from this image to the image to the right, due to raised water elevations

What can we do about it?

As stated, many studies show that changes can occur in the human body due to temperature and greenhouse gasses. Animals can be driven out of their habitat or even killed because of the multitude of effects that are happening because of global warming. Because of the effects that climate change brings on the world it can cause small or even large evolutionary changes in humans and animals, which if prolonged can cause an extinction. These effects could be stopped and even possibly reversed if people stop and see what they are doing and how it affects the world, and maybe if people try to stop the results of climate change and limit it by self educating and taking action even by planting a few trees to even investing in solar panels or electric cars, maybe we have a chance against it.


Cho, Renee. “What Helps Animals Adapt (or Not) to Climate Change?” What Helps Animals Adapt (or Not) to Climate Change?, 3 Apr. 2018, blogs.ei.columbia.edu/2018/ 03/30/helps-animals-adapt-not-climate-change/. Accessed 27 March 2020.

“Cool Temperature Alters Human Fat and Metabolism.” National Institutes of Health, U.S. Department of Health and Human Services, 15 May 2015, www.nih.gov/news-events/nih-research-matters/cool-temperature-alters-human-fat-metabolism. Accessed 27 March 2020.

Greshko, Michael. “What Are Mass Extinctions, and What Causes Them?” Mass Extinction Facts and Information from National Geographic, 26 Sept. 2019, www.nationalgeographi c.com/science/prehistoric-world/mass-extinction/#close.a. Accessed 27 March 2020.

Kluger, Jeffrey. “Sixth Great Extinction: We're to Blame.” Time, Time, 24 Apr. 2017, time.com/3035872/sixth-great-extinction/. Accessed 27 March 2020.

Lindsey, Rebecca. “Climate Change: Atmospheric Carbon Dioxide.” Climate Change: Atmospheric Carbon Dioxide | NOAA Climate.gov, 20 Feb. 2020, www.climate.gov/ news-features/understanding-climate/climate-change-atmospheric-carbon-dioxide. Accessed 27 March 2020.

Meyer, Robinson. “The Human Brain Evolved When Carbon Dioxide Was Lower.” The Atlantic, Atlantic Media Company, 20 Dec. 2019, www.theatlantic.com/science /archive/2019/12/c arbon-dioxide-pollution-making-people-dumber-heres-what-we-know/603826/. Accessed 27 March 2020.

Pearce, Fred. “Global Extinction Rates: Why Do Estimates Vary So Wildly?” Yale Environment 360, 17 Aug. 2015, e360.yale.edu/features/global_extinction_rates_ why_do_estimates_ vary_so_wildly. Accessed 27 March 2020.

Pleul, Patrick. “Some Animals Can Adapt to Climate Change-Just Not Fast Enough.” Many Animals Can Adapt to Climate Change-Just Not Fast Enough, 20 Aug. 2019, www.nationalgeographic.com/environment/2019/08/many-animals-can-adapt-climate-change-just-not-fast-enough-/. Accessed 27 March 2020.

Root, Tik. “Ghost Forest: Dying Trees Show Climate Change's Advance.” Time, Time, 7 Oct. 2019, time.com/5694648/ghost-forests-climate-change/. Accessed 27 March 2020.


Created with images by Tony Reid - "Breathtaking valley" • Kovah - "Potsdamer Platz Arcaden" • Nomadic Julien - "untitled image" • Craig Cameron - "untitled image" • Jason Blackeye - "sunset below Patras windmill"