What Are the 5 Effects of Climate Change?

Human influence on Earth’s climate systems is now an established fact corroborated by observational records and climate models. The term “climate change” broadly refers to the long-term shifts in average temperatures and weather patterns that have been measured since the pre-industrial era. In essence, there are five symptoms associated with climate change: 1) increased surface temperatures, 2) rising sea levels, 3) melting ice sheets, 4) declining biodiversity, and 5) decreased agriculture production.

What Are the Effects of Rising Temperatures?

Rising surface, ocean, and atmospheric temperatures, also known as global warming, is perhaps the most influential symptom of climate change. As average daily temperatures gradually increase, there may be more incidents of heatwaves and droughts. Global warming also adds to the likelihood of wildfire occurrences. Evapotranspiration-the combination of water evaporation, soil moisture evaporation, and plant transpiration-rids soils and vegetation of their moisture. Dried-out plant matter acts as kindling during wildfires and enables the spread of flames.

Excess heat may also be hazardous to human health. People who are exposed to extreme heat can experience a range of conditions, including heat stroke, heat exhaustion, heat cramps, or heat rashes.

Why Is Sea Level Rise a Problem?

Sea level rise is related to the melting of land-ice and thermal expansion in seawater caused by heating oceans. The most affected communities are those along coasts. Coastal systems are more sensitive to rising seas because of their low elevation and proximity to large bodies of water. Erosion from intense wave action and flooding threatens coastal infrastructure more than that of high-elevation and inland territories. On top of that, coasts are highly vulnerable to extreme storms such as tropical cyclones. Coastal storms, including hurricanes and tropical storms, generate powerful ocean waves and harsh winds that indiscriminately damage property and claim lives.

How Does Melting Ice Sheets Affect the Environment?

Ice sheets are permanent masses of ice that cover vast amounts of land in Greenland and Antarctica. Under the influence of global warming, ice sheets melt more quickly. Water from melting land ice inevitably flows into seas and contributes to rising sea levels. In return, increasing amounts of melting sea ice loss reinforce global warming. This is because brightly colored snow and ice surfaces reflect sunlight back into space, whereas darkly colored sea water absorbs sunlight and heat energy. As ice sheets melt, Greenland and Antarctica will continue to heat up, and vice versa.

Permafrost (layers of subsurface soil, gravel, and sand that stay frozen year-round) stores plant material and keep them from decomposing as long as they remain frozen. Thawing these icy structures will allow the natural breakdown of plant materials to take place. When organic materials decompose, an array of greenhouse gases such as methane and carbon dioxide are released into the atmosphere and intensify global heating.

Biodiversity Loss Effects

A report published in 2021 by the Intergovernmental Panel on Climate Change (IPCC) and Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) drew a connection between climate change and biodiversity loss. According to the report, long-term climatological shifts have the potential to adversely alter a wide range of ecosystems.

For example, ocean acidification, which is driven by warming sea temperatures, can be harmful to species that form shells and skeletons from calcium and carbonate. When large amounts of atmospheric carbon dioxide are absorbed by seawater, the water’s pH is reduced and the amount of carbonate ions decreases. Ocean acidification can make shells and skeletons grow more slowly or dissolve more quickly, leaving species like scallops, corals, sea urchins, and clams more prone to impaired health.

How Does Climate Change Affect Agriculture?

The physical effects of climate change could influence agriculture production in a myriad of ways because crops depend on suitable environmental conditions to grow. Crop growth can be disturbed by shifts in air temperature or losses in soil biodiversity.

A 2017 study titled, “Temperature Increase Reduces Global Yields of Major Crops in Four Independent Estimates“, compiled results from four analytical methods (global grid-based models, local point-based models, statistical regressions, and field-warming experiments). They discovered that “without CO2 fertilization, effective adaptation, and genetic improvement, each degree-Celsius increase in global mean temperature would, on average, reduce global yields…”. Exposure to hotter temperatures may therefore contribute to abiotic stress for crops. Assuming that this is true, climate change will make food security threats more pronounced in the future.

How Is Plastic Affecting the Arctic?

ice in the Arctic ocean
Ice in the Arctic ocean

A new review article, “Plastic Pollution in the Arctic“, contends that high levels of plastic pollution (including microplastics) have infiltrated the Arctic and intensified climate change’s effects. Plastics from agriculture, hydrocarbon exploration, landfills, illegal dumping, industry, households, fisheries, offshore industry and other such sources are routinely carried to and within the Arctic by atmospheric and aquatic circulation systems. As plastics move through the Arctic, they gradually break down and release greenhouses gases, including methane and ethylene.

Is There Plastic In the Arctic?

Transported plastics from local and distant sources are broadly distributed throughout the Arctic. The United Nations estimates that approximately 150 million tons plastic debris may be scattered across the Arctic. Plastics are found on Arctic shores, in the water column, in sea ice and in the bodies of marine biota.

How Does Plastic Pollution Affect Marine Life?

Arctic wildlife are known to ingest, become entangled in or smothered by plastic debris. “Plastic Pollution in the Arctic” reports that Arctic species such as sculpin (Triglops nybelini), the northern fulmar (Fulmarus glacialis) and belugas (Delphinapterus leucas) have been found with plastic inside them. Plastic ingestion may even affect marine invertebrates like zooplankton in the east Canadian Arctic and the Fram Strait (a sea channel between Greenland and Svalbard). The review further reports that the organismal impacts of plastic infiltration to many endemic species remain largely unknown.

The Fundamental Links Between Climate Change and Marine Plastic Pollution In The Artic

Plastics drive climate change, in return, climate influences distribution of plastics. Also, both climate change and plastics have oil and gas origins. Plastics are derived from greenhouse gases (GHGs) and continue to release GHGs throughout their life cycles as they degrade. Plastics and microplastics are thus expected to increase ocean heat content (OHC). According to “Plastic pollution in the Arctic”, plastics could also promote glacial thawing by affecting their light absorbance, structure and rheological properties.

Circulation systems, including wind, ocean currents and freshwater river flows, continue to move plastics through Arctic ecosystems long after they are originally introduced. Physical impacts associated with climate change effect the concentrations and distribution of plastic in the Arctic. Sea level rise or higher poleward wind speeds from global warming could transport greater levels of plastic debris to Arctic ecosystems.

These interactions suggest that climate change and plastic pollution are mutually reinforcing. The Arctic may be more sensitive to the effects of ocean warming and plastic pollution than most environments because of its permafrost, snow and ice. Climate change strategies aimed at mitigating ocean warming, will have to account for the emissions from plastic sources as well.

Can Plastic Pollution Cause Climate Change?

An interesting review titled, “The Fundamental Links Between Climate Change and Marine Plastic Pollution”, describes the interactive relationship between climate change and marine plastic pollution. The review’s authors claim that climate change and marine plastic pollution are linked in three ways: a) the production of plastic relies on fossil fuel extraction and is thus a greenhouse gas contributor b) climate and weather influence the distribution and spread of plastic pollution across environments c) marine ecosystems and species are presently vulnerable to both climate change and plastic pollution.

plastic bottle in water

Greenhouse Gas Emissions from Plastic Production

The rise in plastic demand is likely due to its reputation as an inexpensive and lightweight material that has a wide range of uses. Plastic is used for packaging, electronics, toys, utensils, safety gear and infrastructure. Even so, plastic drives greenhouse gas emissions throughout multiple stages of its so-called “lifecycle”, from extraction and refining to transportation, incineration and recycling.

As common plastics degrade, they continue to emit greenhouse gases like methane or ethylene, which intensify ocean warming. Bio-based plastics, plastics made from biomass, are no exception. While bio-based plastics do produce fewer greenhouse gases than conventional plastics, they still release heat trapping molecules during their lifecycles. Degrading plastic products fragment into microplastics and smaller constituents parts that can be toxic to humans and marine organisms.

How Does Plastic Move Around the World?

Climate inevitably influences the movement of plastics between environments. Plastics are circulated by the flow of water and wind. Extreme weather, like floods and windy storms, can move plastics from one system to another. Flooding riverine systems can transport plastics into the ocean; tropical storms from oceans can push plastics into onto terrestrial surfaces. Releasing plastic into the ocean or onto landfills is not the end of that plastic’s life cycle. Plastic and microplastics continue to impact the ecosystems long after they have been disposed of by humans.

How Does Plastic Affect Marine Ecosystems?

Climate change is altering the distribution of many species by subjecting them to novel thermal conditions. When marine habitats heat up, the species within them are usually forced to move to new regions to find more suitable temperatures. Heating oceans also contribute to hypoxic zone and coral bleaching. Plastic, on the other hand, can is ingested by marine species, which can low survival odds. In some cases, marine animals become entangled by plastic products or have their feeding pathways obstructed.

Plastic also potentially facilitates species migrations because plastic debris attracts encrusting organisms and microbial communities. Therefore both climate change and plastic pollution can contribute to species movement between ocean regions. Increased species mobility can bring about invasive species risks.

How Does Plastic In the Ocean Affect Climate Change?

Authors of the review, “The Fundamental Links Between Climate Change and Marine Plastic Pollution”, reason that climate change and plastic pollution are fundamentally linked to one another. Plastic production is heavily dependent on fossil fuel use and the release of greenhouse gases as it degrades in oceans, both of which enhance ocean heating and climate change. Plastic dispersal across environments influenced by climate change-driven extreme weather. Marine ecosystems and species are vulnerable to these threats.

How Has Climate Change Affected Yellowstone Amphibians?

A new study published in the science journal Ecology Indicators highlights how environmental changes in Yellowstone National Park are leading to habitat loss for some amphibian species. As Yellowstone continue to heat up and dry out under the influence of climate change, certain amphibians that move across the park are expected to experience loss of habitable zones. Authors of the study predict that continued climate change will “reduce snowpack, soil moisture, and forest cover” and diminish wetland habitats throughout Yellowstone National Park.

Will Amphibians Survive Climate Change?

Amphibians are ectothermic, meaning that they absorb heat from external sources in their environment to regulate their body temperatures. That being the case, hotter temperatures are potentially beneficial to amphibians in certain microclimates. Microclimates are small, restricted sections of an area that have different climatic states relative to the surrounding space. Warmer microclimates can help amphibians survive through the winter or forage for provisions during the day. However, warming temperatures that also drive dryer air and soils can limit amphibians’ ability to rehydrate while traveling cross stretches of land.

Amphibian hydroregulation is likewise dependent on factors in their environment, as they are unable to control water evaporation from their bodies. Amphibians require humidity and sufficient water availability to avoid dehydration. Terrestrial habitats that lack moist soils and forest cover from direct sun exposure can impede amphibians’ thermo-hydroregulation abilities.

How Has Climate Change Affected Yellowstone National Park Amphibians?

Researchers of the amphibian-Yellowstone study mechanistically modeled the movement of amphibians within the park for the years 2000, 2050 and 2090 to gauge the “costs” (disadvantages) to amphibians under the influence of climate change. Model simulations included data relating to Yellowstone’s vegetation, weather and details about animals’ morphology and physiology. Western Toads (Anaxyrus boreas) were used as the subject species for the model. Inferences were then made about other amphibians native to the park.

How Did Amphibians Adapt to Their Changing Environment?

The results were mixed across the three “test areas” which were modeled; in one of the test areas, physiological movement costs increased, decreased in the second and were mixed in the last. Authors of the study “predict that climate change will reduce the physiological costs for toads in some regions of YNP but increase them in others”. Snowpack loss and drying conditions throughout portions of Yellowstone may shrink wetlands, which could limit breeding sites for toads and make travel between breeding sites more costly. Other amphibian species are expect to experience worse consequences from warming and drying climates than toads. For example, Boreal Chorus Frogs (Pseudacris maculata), are less resistant to desiccation than toads because they are more dependent on wetlands.

Are Amphibians Sensitive to Climate Change?

Strictly speaking, warming conditions do not affect all amphibians in Yellowstone National Park the same. Variations in weather and vegetation cover brought on by climate change may make moving across the stretches of land that surround wetlands more costly for some amphibian species, particularly those less tolerant to dry habitats.

What Are Direct and Indirect Effects of Climate Change?

Freshwater systems provide usable water for technological development, agriculture and human consumption, while also serving as habitats for various aquatic species. Therefore, freshwater systems are of crucial economic and ecological value. A 2021 study titled, ” “The Importance of Indirect Effects of Climate Change Adaptations On Alpine and Pre-Alpine Freshwater Systems” asserts that human-made transformations in water hydrology and pollution from sewer outflows and agriculture chemicals are threats to freshwater systems. Properly accounting for the effects of climate change and anthropogenic influence on aquatic environments will hopefully improve climate change adaptation policies.

What Is Freshwater?

Rivers, reservoirs, and streams are examples of freshwaters systems. Freshwater is a subset of Earth’s water which is significantly less salty than marine waters (like seas and oceans). The United States Geological Survey, a branch dedicated to science within the United States Department of the Interior, defines freshwater as “water containing less than 1,000 milligrams per liter of dissolved solids, most often salt.” Though freshwater is renewed through the water cycle, it is a finite resource. If freshwater is used more quickly than it is naturally replenished, water security risks may be enhanced.

What Are Direct and Indirect Effects of Climate Change?

Authors of “The Importance of Indirect Effects of Climate Change Adaptations On Alpine and Pre-Alpine Freshwater Systems”, regard higher frequency of extreme meteorological events and increased temperatures as “direct effects” of climate change. These direct effects adversely influence the state and quality of aquatic regions. Direct effects also interact with human responses to climate change and produce “indirect effects”.

So-called indirect effects refer to human practices that are aimed at climate change mitigation. Indirect effects include land-use changes, alterations to freshwater systems and increasing irrigation practices. Authors suggest that “indirect effects may, at least in the short term, overrun the impact of direct climate change on water bodies.” Though all biomes are predicted to be impacted by climate change, freshwater systems in alpine and pre-alpine regions may be disproportionately at risk due to agriculture and hydropower plants.

Adapting Water Management to Climate Change

Freshwater use for the production of energy, also known as hydropower, is typically made possible by dams and in-stream structures. Hydropower infrastructure generates usable electricity for homes and businesses. Authors of the 2021 review article posit that hydropower is used as an alternative to nonrenewable energy resources. Hydropower production is therefore considered an adaptation strategy to climate change. Hydropower installations in freshwater networks can fragment or isolate certain species populations which are ill-adapted for the changes in water flow and perpetuate biodiversity loss. By modifying the hydrology of freshwater systems, water usage for energy production can compound the direct effects of climate change to aquatic flora and fauna.

How Does Agriculture Affect Climate Change?

Agriculture can be of detriment to freshwater systems as well, but in a much different way than hydropower plants. Climate change can intensify extreme weather event trends, such as floods, storms and droughts; these effects can drive diminished crop yields. In the interest of mitigating threats to crops brought on by climate change, agriculturalists may expand irrigation infrastructure or enhance fertilizer use. These adaptations can exacerbate the consequences which are already affecting crop growth cycles.

What Is the Impact of Climate Change On Water Resources?

Authors of the 2021 review claim that “rain-fed dairy farming is currently the most predominant form of agriculture, but in the future these grasslands may become more and more dependent on irrigation”. Redirecting water for irrigation use can potentially limit the quantity of water available in freshwater ecosystems. Variability in weather regimes may contribute to further dependence on water from irrigation (rather than from rainfall) in the future. Some of the responses that agriculturalists are expected to as a response to a changing climate pose risks to freshwater systems. Policy makers must account for indirect impacts to alleviate worsening the ecological status and water quality within aquatic environments.

Climate Change Impacts on Seabirds and Marine Mammals

A new review published in Ecology Letters, a peer-reviewed scientific journal, assessed seabird and marine mammals’ responses to climate change and climate variability. Researchers based their analysis on data from more than 480 preexisting studies and found that “the likelihood of concluding that climate change had an impact increased with study duration”.

In other words, detecting the influence of climate change on certain species requires long-term observations. Furthermore, the analysis posits that species which had more limited temperature tolerance ranges and relatively longer generation times were reported to be most affected by changes in climate. (Generation times are temporal intervals between the birth of an individual organism and the birth of its offspring).

Seabird species: Australian Pelican (Pelecanus conspicillatus)

How Does Climate Change Affect Marine Life?

From the 484 peer-reviewed studies that matched researcher’s inclusion criterion, 2,215 observations were compiled into a database and mapped. This includes 1,685 observations for seabirds and 530 observations for marine mammals. 54% of observations for seabirds were distributed towards northern hemisphere (39% of observations from temperate and polar regions). For marine mammals, 83% of observations were distributed toward the northern hemisphere (53% of observations from temperate and polar regions). For both seabirds and marine mammals, tropical and subtropical regions represented a mere 8% of total observations.

What Marine Life Is Most Affected by Climate Change?

Authors of the preexisting studies found 38% of total observations to be related to climate change, 49% were attributed to climate variability, and 13% were attributed to both. Reproductive success and adult survival were the most common response variables studied on both taxonomic groups (60% for seabirds and 34% for marine mammals). According to the new review, “a significant majority of observations concluded that climate change had an effect on both the seabird and marine mammal groups for all the response classes”. Response classes include demography, distribution, condition, phenology, behavior and diet.

How Does Climate Change Affect Marine Biodiversity?

The longer the duration of the original studies, the more likely authors were to infer that the observed changes in taxonomic groups were due to climate change rather than climate variability. 189 of the preexisting studies (669 observations) that demonstrated climate change effects had a time span above the estimated average threshold of 19 years. Generally, studies on marine mammals were able to demonstrate climate change responses based on shorter time scales (17± 5 years) versus seabirds (22 ± 3 years).

Ecology of Fungi

Fungi- (singular; fungus) have a true nucleus, meaning that they are eukaryotic organisms and reproduce (both sexually and asexually) by spores. Fungal spores are primarily disseminated through wind. Fungi have crucial ecological roles in transporting nutrients through underground fungal hyphae networks, decomposing dead biomass material and serving as food for some mammals, including us humans. Although, some fungi are poisonous and can cause disease, this serves as a consequence of their vast biological diversity. Fungi come in numerous species and have been found in marine, terrestrial and freshwater environments.

gang of mushrooms growing from soil
gang of mushrooms growing from soil

Fungi Evolution

According to a 2020 study from the Université libre de Bruxelles posits that the first mushrooms evolved on Earth between 715 and 810 million years ago, predating other estimates by roughly 300 million years. The fossilized remains of mycelium in sediments leads Steeve Bonneville, leader of the study and professor at the Université libre de Bruxelles to believe that microscopic mushrooms were associated with early plant predecessors.

However, the origin of fungi are still quite mysterious. Estimates range in the true number of mushroom species that exist, as very few of them have been identified. Recent research suggests that as many as 5 million or more fungal species may exist. John Todd, Canadian ecologist and author of “Healing Earth” asserts that fungi evolved from Protists – one of the six kingdoms of life – about 1 billion years ago. The long history of fungi are telling of their evolutionary adaptability throughout Earth’s climatological and biological changes.

Is Fungi A Plant or Animal?

Fungi were once thought to be entirely immobile, however, some species have mobile phases. Motility has long been conceptualized as a characteristic inherent to plants. Plants are also known to produce their own food. Fungi are similar to animals in that they don’t produce their own food. Like animals, fungi are heterotrophs; in other words use digestive enzymes to dissolve and integrate nutrients. Also fungi do not share the cellulose found plant cells, instead, fungal cell walls contain chitin, which are polycarbohydrates made from chains of glucose. As counter intuitive as it seems, fungi appear to have striking resemblances to animal organisms rather than plants.

Importance of Mushrooms | What Are The Ecological Benefits of Fungi?

The mutualistic symbiotic relationship between plants and photosynthetic organisms – a symbiosis known as mycorrhiza – is one of the most vital support systems for plant growth, including aquatic vegetation like algae. In a mycorrhizal interaction, the fungal mycelia extend a network of hyphae to channel water and nutrients like phosphorous and nitrogen to plant root systems underground. In exchange, mushrooms benefit by receiving sugars produced by plants.

Fungi in the saprophyte grouping are important because they act as decomposers in most ecosystems that they are part of and recycle organic matter. Many fungi draw nutrients from dead or decaying content (particularly carbon- and nitrogen-containing compounds) and use specialized enzymes to break down complex molecules, these nutrients are then released into soils and plants. In doing so, fungi accelerate the rate at which deceased organic material degrades and is reabsorbed into the ecosystem by plants and bacteria.

Ecological Community: Networks of Interacting Species

An ecological community is defined as a group species that inhabit the same place and interact with each other in various combinations. In ecology, communities are the biotic components of an environment, including its Archaebacteria, Eubacteria, Fungi, Protista, Plantae and Animalia, these are the six known kingdoms of Earth’s biosphere. The organisms that share a close genetic heritage and/or can potentially interbreed to create offspring are generally considered to be of the same species.

Groups of species that inhabit the same area are referred to as populations; ecological communities consist of all the interconnections among species’ populations. Just like the abiotic factors in an environment – like weather or availability of water – species interactions contribute to natural selection pressures. Natural selection determines which organisms live long enough to reproduce and which do not. Interactions shape the environment and the evolution of species through time.

Community ecology as a discipline seeks to answer questions about how species interact and what drives their patterns of diversity and distribution. The ways in which species interact can range greatly. Species exchange nutrients, consume one another, compete for resources like sunlight and space, and help each other out in some cases. There are five main types of interactions between species: competition, predationmutualismcommensalism and parasitism. These labels are known as interspecific interactions, and they represent how species are affected by other species that they deal with.

Some interactions result in benefits for one species group, and disadvantage the other interacting species group. This interspecific interaction can fit into the parasitism category or the predation category. Interactions of this sort can be simplified as (+/-); the “+” represents the benefit for one species while “-” refers to the detriment to the other. Other interactions can produce mutual benefits for both species, (+,+). In cases like these, its not uncommon for there to be a sort of coevolution at work, where both species have evolved specific adaptations to facilitate the services that they provide while also benefiting themselves. We can apply + and – to further depict how species are affected or unaffected by their relationships to one another: competition (-/-), predation (+/-), mutualism, (+/+), parasitism (+/-), and commensalism (+/0). Commensalism is an example in which one species gains some benefit while the other species loses nothing but also gains nothing.

Competition

Competition (-,-) is an interaction in which organisms of two or more species use the same resource. Any given resource will be limited, and may have significant costs for either of the organisms involved.

Predation

Predation (+,-) is an interaction that involves one species eats (and in some cases also hunts) another (the latter species is often called prey). Some ecologist extend the term predation to include herbivorous consumption. This is because the general principle at play is one species is consuming another.

Commensalism

Commensalism (+/0) is an interaction in which organisms from one species are able to benefit at no cost to the other species that it is interacting with.

Parasatism

Parasitism (+,-) is characterized by the benefit of one species at some cost or harm to members of the a targeted species. Its common for parasitic organisms to live inside, or otherwise attach themselves to the targeted organisms (sometimes called hosts).

Mutualism

Mutualism (+,+) occurs when both of the involved species benefit from the interaction, which may motivate a long term association between them. We explore an example of this type of interspecific interaction below.

Ecological Community Interaction Example

The relationship between pollinators and plants is a classic example of a mutualistic relationship (+,+) that is rooted in a long and intimate coevolutionary relationship. Pollinators visit flow after flower to collect pollen and other nectars which the pollinator uses as food. Bees are a classic example pollinators. Bees, like other pollinators benefit by feeding on nectars and pollens for nutrients. Plants benefit by having their pollen efficiently distributed to other flowers of the same species, this is one way in which flowers pollinate, another way is by wind carrying pollens between male and female flowers. Pollination plays an essential role in plant reproduction. Once a female part of a flower (stigma) receives pollen from a male portion (anthers), fertilization can take place.

bee pollinating white flowers
bee pollinating white flowers

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Cowspiracy Ocean Facts Summary

Fisheries harvest marine organisms across the globe. While fisheries do generate food and profit, they could be doing much more harm than good for underwater ecosystems. The film Cowspiracy makes a convincing case for the deleterious affect that large-scale fishing operations have on ocean environments, species variety and species abundance. Cowspiracy depicts modern fishing as a largely unsustainable industry that could lead to fishless oceans by 2048.

fish near water surface
Fish near water surface

Fishing As Depicted By Cowspiracy

Fish and other marine life are mostly hunted as food. However, some species are used for other commodities. Sharks, for example, are sometimes hunted for their skin which can be used in the making of leather. Other species like whales and manatees are regularly harmed or killed unintentionally by getting caught in fishing nets. The Cowspiracy Facts page sites a Food and Agriculture Organization (FAO) document which states that in the year 2017, between 51 – 167 billion farmed fishes had been killed for food. That same year an estimated 250 – 600 billion crustaceans were also farmed and killed for food. Even animals that are not eaten by humans are caught and killed inadvertently because of drift netting or trawling. Susan Hartland of Conservation Society says that animal populations are being extracted from oceans more quickly than they can recover. Marine species are therefore collapsing under the immense pressures of modern hunting. The unintended catches, sharks, sea turtles and dolphins, are referred to as bykill.

Keystone Species and Trophic Cascades

Apex predators often act as keystone species, meaning that they have disproportionately large effects in their natural environments. This makes the removal of sharks particularly concerning. As top predators, many sharks species exert top down influence in their respective food webs. The removal of sharks, and other keystone species increases trophic cascade risks. Trophic cascades are the ecological chain of events triggered by the removal or addition of top predators.

Agriculture, Fishing and Algae Blooms

“Livestock operations on land have created more than 500 nitrogen flooded dead zones around the world in our oceans…” According to Dr. Richard Oppenlander, an environmental researcher featured in the Cowspiracy film. Water pollution comes in the form of pesticides, herbicides, heavy metals, plastics and other waste material. However, animal agriculture is the leading cause of ocean pollution – a fact which is stated explicitly in the Cowspiracy film. Animal agriculture run-off upsets nutrient balances in aquatic ecosystems by introducing phosphorus, nitrogen, manure and potassium from chemical fertilizers. These excess nutrients can cause alae blooms, leading to uninhabitable zones for marine species. Blooms of algae drain sunlight and deplete oxygen levels – making the environment unsuitable for most other lifeforms in the ecosystem.

Bottom trawling contributes to inhabitable zones similarly. Bottom trawling, also referred to as “dragging” involves casting a fishing net to the sea floor. Trawling disturbs sediments along the sea floor which causes carbon to be released. Once carbon dioxide is released from sediments, it is then absorbed by ocean seawater. Elevated carbon levels allow water to trap in more heat and further facilitate algae and plant overgrowth.

Cowspiracy Summary: Rainforest Facts

The official Cowspiracy website lists references aimed at supporting the arguments and conclusions proposed in the film on its “Facts” page. The page of supporting documents has 9 categories, including Ocean, Wildlife, Land, Waste, Water, Greenhouse Gases, Rainforest and Humanity. The documents listed in the Rainforest facts section describe the importance of rainforest ecosystems and demonstrate the effect that poor land use – such as monoculture farming, cattle ranching, conversions deforestation and development – have on rainforest ecosystems. We’ve devised a terse summation of the curated Cowspiracy texts with the hope of illustrating the ecological costs associated with land misuse.

Ecological Degradation

Rainforest ecosystems are inhabited by more plant and animal species than any other terrestrial ecosystem. The Cowspiracy Facts page states in one of its Rainforest subtitles that “the leading cause of rainforest destruction are livestock and feed crops”. Clearing forests to make way for land pastures and agriculture feed plots is done in Costa Rica, Honduras, and El Salvador to meet the demand for American beef. Cattle ranching is a low cost, low maintenance operation to run in the tropics. Cattle ranching generates profit for land owners, farmers and distributors.

Nonetheless, livestock feeding plots require sections of forests and other vegetation to be cleared first to make space for pastures and animal crops. Clearing vegetation can increases risks to various processes that rainforest vegetation help carry out, including enhanced water absorption into soils, sequestration of greenhouse gases from the atmosphere, summoning rainfall, providing nutrients to plant-consuming species and serving as habitats for arboreal species. These are examples of ecosystem services provided to rainforest environments and the species within them. Services like these emerge from the biological, chemical and physical functions in rainforest environments.

wild tropical flowers
tropical flowers

“What Cowspiracy: The Sustainability Secret” Says About Rainforests

The growth of human populations has driven our demand for food and textiles to rise, which has ramped up animal agriculture in tropical forests. According to the Food and Agriculture Organization (FAO), agriculture approximately 15% of the Amazon forest has been removed due to agricultural practices since 1960s. Of the land being used by humans, 80% of it is dedicated to grazing areas for horses, cattle, sheep, or pigs. Put another way, cattle ranching for agriculture is the central use of land in the Amazon basin, which includes Brazil, Peru and Bolivia, Colombia, Venezuela, Ecuador, Guyana, Surinam and French Guyana. These regions are subjected to slash and burn clearing before feeding pastures can be established. Therefore, cattle ranching is the leading cause of deforestation in the Amazon Basin. On top of that, animal agriculture contributes to methane emissions, ocean acidification and worsened air quality.

Save The Amazon

Savetheamazon.org refers to the plant and animal species of the Amazonian rainforests as its “wealth’. The site posits that up to 80% of developed nation’s diets are sourced from tropical rainforests. Our fruits, (avocados, coconuts, figs, oranges, lemons, grapefruit, pineapples, and tomatoes) vegetables (corn, potatoes and yams) spices, (cayenne, chocolate, cinnamon, ginger, sugar cane, turmeric) have their origins in tropical ecosystems.

Without these contributions, the diets of developed nations would be severely restricted. Equally as important, rainforests like the Amazon help abate flooding by storing tremendous amounts of rainwater in its plants and soils. However, the continued functionality of tropical rainforests depends on how sustainably we use the land. Harvesting from rainforests at rates faster than they are able to naturally replenish themselves may contribute to permanent changes of the ecological structures within rainforests.