What Are Biggest Threats To Earth's Biodiversity

 

Climate change and air pollution has been a cause of major concern across the world as it is causing damage to the Earth's biodiversity. But according to the recent study conducted by the World Wildlife Fund's (WWF) Living Planet Report 2020, there is more than just climate change which is causing threat to the planet Earth. Here's a look at the five biggest threats to Earth’s biodiversity and the impact each has had globally.

Climate Change

Climate change is at that effects a 6 percent threat to the Earth's biodiversity. 

Climate change includes both the global warming driven by human emissions of greenhouse gases, and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century the rate of human impact on Earth's climate system and the global scale of that impact have been unprecedented.

That human activity has caused climate change is not disputed by any scientific body of national or international standing.The largest driver has been the emission of greenhouse gases, of which more than 90% are carbon dioxide (CO2) and methane.

Fossil fuel burning for energy consumption is the main source of these emissions, with additional contributions from agriculture, deforestation, and industrial processes.Temperature rise is accelerated or tempered by climate feedbacks, such as loss of sunlight-reflecting snow and ice cover, increased water vapour (a greenhouse gas itself), and changes to land and ocean carbon sinks.

It triggers irregular seasonal change such as migration and reproduction causing it to happen at the wrong time. 

Pollution 

Pollution ranks at no 4 that is responsible for a 7 percent threat to the Earth's biodiversity. Pollution is the introduction of harmful materials into the environment. These harmful materials are called pollutants. Pollutants can be natural, such as volcanic ash. They can also be created by human activity, such as trash or runoff produced by factories. Pollutants damage the quality of air, water, and land.

Many things that are useful to people produce pollution. Cars spew pollutants from their exhaust pipes. Burning coal to create electricity pollutes the air. Industries and homes generate garbage and sewage that can pollute the land and water. Pesticides—chemical poisons used to kill weeds and insects—seep into waterways and harm wildlife.

All living things—from one-celled microbes to blue whales—depend on Earth’s supply of air and water. When these resources are polluted, all forms of life are threatened.

Pollution is a global problem. Although urban areas are usually more polluted than the countryside, pollution can spread to remote places where no people live. For example, pesticides and other chemicals have been found in the Antarctic ice sheet. In the middle of the northern Pacific Ocean, a huge collection of microscopic plastic particles forms what is known as the Great Pacific Garbage Patch.

Air and water currents carry pollution. Ocean currents and migrating fish carry marine pollutants far and wide. Winds can pick up radioactive material accidentally released from a nuclear reactor and scatter it around the world. Smoke from a factory in one country drifts into another country.

Invasive Species

Invasive species is on the third place with an average of 13 percent threat to the Earth's biodiversity. Invasive species are among the leading threats to native wildlife. Approximately 42 percent of threatened or endangered species are at risk due to invasive species.

Human health and economies are also at risk from invasive species. The impacts of invasive species on our natural ecosystems and economy cost billions of dollars each year. Many of our commercial, agricultural, and recreational activities depend on healthy native ecosystems.

An invasive species can be any kind of living organism—an amphibian (like the cane toad), plant, insect, fish, fungus, bacteria, or even an organism’s seeds or eggs—that is not native to an ecosystem and causes harm. They can harm the environment, the economy, or even human health. Species that grow and reproduce quickly, and spread aggressively, with potential to cause harm, are given the label “invasive.”

An invasive species does not have to come from another country. For example, lake trout are native to the Great Lakes, but are considered to be an invasive species in Yellowstone Lake in Wyoming because they compete with native cutthroat trout for habitat.

Species Overexploitation

Species overexploitation is the second biggest threat with a contribution of 24 percent danger to Earth's biodiversity. There are two ways of overexploitation: direct and indirect. 

Overexploitation means harvesting species from the wild at rates faster than natural populations can recover. Overfishing and overhunting are both types of overexploitation. Currently, about a third of the world's endangered vertebrates are threatened by overexploitation.

Two birds that were victims of overhunting are passenger pigeons and great auks (a type of bird). Both were hunted to extinction. American bison came close to extinction when they were hunted for their skins in the 19th century but have recovered, so luckily it's still okay to eat bison burgers (sorry, vegetarians!). Overhunting still poses a big threat to animals in developing regions, particularly primates in Africa.

Most of the land animals we eat are farm-raised, not hunted in the wild. Fish, on the other hand, are often still fished from the wild. Humans have to eat, but we have been taking fish for food faster than they can replenish their wild populations. It is estimated that 63% of commercial fisheries are overfished to some extent.

Overfishing happens mostly because humans have gotten really good at fishing. We have big boats, fancy GPS systems, and mechanized fishing lines. The fishing techniques called bottom trawling and dredging involve dragging huge heavy nets across the ocean floor, picking up everything along the way. This includes plants and animals that are not the target fish. These unwanted things usually get tossed out. All this other, non-target catch is called bycatch. Bycatch can include sea turtles, sharks, corals, and lots of other animals. These fishing methods are super destructive of habitats on the bottom of the ocean, especially slow-growing corals, in both warm and cold water.

Changes in land and sea use

Changes in land and sea use: According to the WWF report, changes in land and sea use account for the largest portion of threat to biodiversity with 50 percent recorded on average. 

This refers to modification of the environment where a species lives by logging, housing development, commercial development, unsustainable agriculture, energy production, transportation and mining. For freshwater habitats, fragmentation of rivers and streams and abstraction of water are common threats.

The report notes that agriculture expansion is the most widespread form of land-use change globally, with more than one-third of the land surface being used to grow crops or farm animals.  

“This expansion, alongside a doubling of urban area since 1992 and an unprecedented expansion of infrastructure linked to growing population and consumption, has come mostly at the expense of forests (largely old-growth tropical forests), wetlands and grasslands,” reads the report. 

To put that into perspective, more than 85 percent of the world’s wetlands that existed in 1700, were gone by the year 2000.  

In Florida, we can relate on so many levels.  We are home to one of the world’s largest wetlands, the Everglades National Park. And, agriculture is Florida’s second largest industry next to tourism.