Biodiversity is the connection among all living things on the planet. At best, scientists have identified only a small percentage of the species on the planet -- less than 1.5 million. However, experts estimate that there are anywhere from two to 100 million species on the planet, and we're losing species at the rate of up to 0.1 percent (of all species) per year. This is 10,000 times the speed at which natural selection would eliminate species without human intervention [source: Equator Initiative].
As species disappear, the changes in the environment become deeper and more serious. Biodiversity is affected. The disappearance of a single species changes the dynamics of the surroundings for all other species, and these changes can also affect humanity at a much deeper level. Many of the synthetic drugs we use today are of natural origin, and if species disappear, so can possible cures.
So what's threatening biodiversity? A lot of things -- and some of them might just surprise you.
Let's take a look at 10 of the biggest threats to Earth's biodiversity.
10: Building Better Roads
New roads and urbanization mean the loss of habitats for many species. As roads are built, animals are displaced. Those who are not scared away or killed during construction run the risk of being injured by traffic. More roads also mean more noise, and noise pollution can drive animals away, forcing them to set up homes in new areas just to avoid crossing the road. As an animal population grows or diminishes in one specific area, other species, plant life and even the soil are affected.
Human intrusion takes many forms. Even where roads are not being built, people are laying down phone and electric lines, as well as building TV and telecommunication towers. Even building a new golf course can affect biodiversity, unless it's planned well and located in a place where it's not invading wildlife space.
9: Having a Baby
Between 1950 and 2008, the world's population more than doubled, growing from 3 billion to 6.9 billion [source: Ontario Ministry of Natural Resources]. According to experts, we're looking at reaching a number close to 9.5 billion people by the year 2050. Even with healthy ecosystems and crops growing at full capacity, Earth can only sustain a limited number of people. As the population grows, so does the carbon footprint that humans leave on the planet. More people mean that more wild land needs to be converted to farming land, more pollution is created and more natural habitats are invaded. As cities grow to accommodate the ever-increasing population, natural spaces get smaller, affecting the animals and plant life in them.
8: Owning a Car
Fossil fuel combustion is one of the most serious environmental pollutants in the world. Exhaust emissions are the primary cause of this, but pollution also comes from the evaporation of stored gasoline and other fuels. The less efficient a car is, the worse the problem becomes, because it consumes more gas and produces more emissions. Cars that aren't properly maintained can smoke or produce visible emissions. This smoke is caused by incomplete combustion, which releases toxic chlorofluorocarbons (CFCs) into the air.
And the problems don't stop there. Old tires end up in landfills, where they're often burned, releasing more CFCs. People sometimes dispose of coolants, lubricants and other car products through the sewers, which empty into rivers or other water sources. These chemicals mix in with the water and end up in the fatty tissue of fish, then traveling on up the food chain.
7: Buying an Exotic Pet
Overhunting animals for fun can affect not only the animals themselves, but also their habitats. Exotic animals such as rhinos are hunted for their purported medicinal benefits. Elephants are hunted for their ivory. Crocodiles are hunted for their skin, which is turned into expensive leather products.
But even owning an exotic pet can seriously affect the environment, not only because it takes animals out of their natural ecosystems, but also because it encourages humans to go into a particular area frequently to catch those animals. This human interaction can affect the soil, cause animals to migrate and reduce wildlife populations. And then there's the risk of introducing new species into the ecosystem. Unfortunately, many pet owners are not aware of how difficult it is to care for an exotic animal. Once the animal outgrows its cuteness or becomes hard to handle, its owners might release it into the wild. According to the Florida Fish and Wildlife Conservation Commission, more than 250 new species have appeared in Florida within the last 200 years [source: Iguana Invasion]. Of those, most started as single pets that were released into the wild. This includes the red-eared slider turtle, the spectacled caiman, cane toads, and non-native fish and snails. These species either prey on local animals, reducing their populations, or cause changes in the environment and the wildlife in the area.
6: Introducing Non-native Species
One of the easiest examples of how a non-native species can forever change the landscape of an environment is in Australia. Until 1859, only a few captive rabbits existed in Australia. Then, 12 wild rabbits were imported and released onto the land. In less than 50 years, the population grew to become a major plague. The rabbits ate the local vegetation, causing soil erosion and leaving little food available for other species.
The same thing happened when Australia introduced cane toads. They were brought in to eat pest beetles, but they ended up eating other species as well. The toads also produce a toxic substance to protect themselves against predators. As a result, a large number of animals that don't have resistance to the venom because they have never encountered the toad before have been poisoned when trying to eat the toads. The government of Australia has found evidence of anything from freshwater crocodiles to quolls and snakes that have been killed because they tried to eat cane toads [source: Australian Government]. As predators die, other animals will prosper, affecting the environment in the process.
5: Buying from Large Corporations
Farming, especially on a large scale, can have serious repercussions on the environment. Fertilizers and other chemicals used to prevent pests or increase soil nutrition can easily wash out and find their way into rivers and streams, where they may be toxic to fish or other animals that drink or live in the water. Large factories are also notorious for dumping waste into local waters, not only causing pollution, but also spreading bacteria. Bacteria, in turn, can cause algae to reproduce faster, robbing the waters of oxygen and killing fish and other aquatic wildlife.
More than twice as many bird species and beneficial insects can be found on small farms compared to large farms; large farms are more likely to use pesticides and other products that might drive animals away and affect the ecosystem [source: Deinlein].
So what's one solution? Support local, organic farms. Buy from small companies rather than large corporations, or take some time to research the company to ensure it's as green and environmentally conscious as possible.
4: Not Taking Care of Your Health
The less you take care of your health, the more you have to rely on medication to help you get better. More than half of the drugs we use today are of natural origin, and this is without counting the large percentage of the population around the world that relies on herbs and natural medicine to treat illnesses [source: Equator Initiative]. In a desperate attempt to treat diseases, scientists scout the world and natural environments that would otherwise be left intact.
However, the main effect of drugs on the environment is through people -- literally. When you take medicine, most of it is absorbed by your body, but some of it passes through and is excreted through urine or feces. This residue ends up in the sewer system and eventually in our water, where it's ingested by fish and wildlife. While moving water might help dilute the effects of a drug, residue that ends up in lakes or small bodies of water can have a very toxic effect on the environment.
3: Eating Meat
Deforestation in South America is mainly due to the increasing need for open land to grow livestock. In fact, 60 percent of the deforestation happening in Brazil is due to cattle ranches [source: Butler]. Many of the large meat producers and exporters of the world obtain their meat from animals raised in South America, simply because it's cheaper and easier to raise animals there. As the size of the Amazon dwindles, thousands of species disappear with it.
Livestock grown in the United States and Europe is fed either through grazing or with grains, and both can cause problems if not handled properly. For example, letting the animals feed on a small area can cause overgrazing, which can affect the soil and other species that feed or live on it. Feeding grain to livestock means larger spaces are needed to grow crops, taking over open land that once belonged to wildlife. In the United States alone, 80 percent of the corn grown goes to feed livestock [source: United States Environmental Protection Agency]. Reducing meat consumption is probably one of the easiest ways to protect the environment and preserve biodiversity.
2: Not Recycling
Only 28 percent of the waste produced in a household is ever recycled or composted: Most ends up in landfills, and a small percentage is burned at combustion facilities [source: United States Environmental Protection Agency]. As trash rots, it produces a large amount of gases, which make their way into the air or infiltrate nearby bodies of water. Toxic things like batteries and chemical products are especially damaging, but rubber, plastic and other common household items are also a problem. One of the gases produced by rotting garbage is methane, which can be explosive if we don't manage it properly and prevent it from building up in enclosed containers or facilities.
When it comes to paper, the statistics are even more startling. To produce virgin paper fiber, we need trees. Today, most of the lumber used in paper production comes from managed forests, which have been planted specifically for this purpose. However, these forests tend to be very uniform, usually consisting of a single type of tree and little other vegetation growing nearby. Lack of diversity affects the interaction of species and can damage the ecosystem. Making paper from scratch also requires up to 70 percent more energy and 790 more gallons of water than it would require to recycle the same amount of paper [source: Waste Online].
1: Killing Insects
Pest insects can ruin anything from a small garden to large farm crops. Insecticides, pesticides and other chemical means of control can help, but there's a price to be paid for their use. For starters, many products that kill pest insects will also kill beneficial insects, including bees, ladybugs and worms. Unless you take the time to identify the pest insect properly and research a way to kill it, you might end up causing major damage to the ecosystem.
To learn more about ecosystems and the environment, check out the links on the next page.
Lots More Information
- 10 Ways Life Has Adapted to Its Environment
- 10 Ecosystems Devastated by Invasive Species
- Top 5 Invasive Species You Should Know
- 10 Examples of Natural Selection
- 10 Controversial Genetic Experiments
- 10 Most Important Insects in the World
- Ultimate Insects and Biodiversity Quiz
- Importance of Biodiversity Puzzles
More Great Links
- Equator Initiative
- National History Museum: Biodiversity and WorldMap
- Center for Applied Biodiversity Science
- AstraZeneca. "Understanding the effects of our medicines on the natural world is a long-standing commitment for AstraZeneca." June 3, 2010. (Sept. 14, 2011) http://www.astrazeneca.com/About-Us/Features/Article/20100603--Understanding-the-effects-of-our-medicines
- Australian Government. "Feral animals in Australia." (Sept. 14, 2011) http://www.environment.gov.au/biodiversity/invasive/ferals/index.html
- Butler, Rhett. "Deforestation in the Amazon." Mongabay.com. Jan. 7, 2009. (Sept. 14, 2011) http://www.mongabay.com/brazil.html
- Deinlein, Mary. "When it Comes to Pesticides, Birds are Sitting Ducks." Smithsonian National Zoological Park. (Sept. 14, 2011) http://nationalzoo.si.edu/scbi/MigratoryBirds/Fact_Sheets/default.cfm?fxsht=8
- EPA Victoria. "Cars and Air Pollution." (Sept. 14, 2011) http://www.epa.vic.gov.au/air/aq4kids/cars.asp
- Equator Initiative. "Biodiversity Facts." (Sept. 14, 2011) http://www.equatorinitiative.org/index.php?option=com_content&view=article&id=565&Itemid=633&lang=en
- Fitzgerald, Mary. "A world too full of people." NewStatesman. Aug. 30, 2010. (Sept. 14, 2011) http://www.newstatesman.com/print/201008300034
- Iguana Invasion. "Exotic Pets Gone Wild in Florida." (Sept. 14, 2011) http://www.iguanainvasion.com/other_exotics.html
- Ontario Ministry of Natural Resources. "Threats to biodiversity." June 5, 2009. (Sept. 14, 2011) http://www.mnr.gov.on.ca/en/Business/Biodiversity/2ColumnSubPage/STEL02_166814.html
- Quebec University. "Impacts on Biodiversity: Population growth, overconsumption and technology." (Sept. 14, 2011) http://redpath-museum.mcgill.ca/Qbp/3.Conservation/impacts.htm
- Rudolf, John Collins."Vietnam Raids Restaurants Selling Exotic Meats." The New York Times. Sept. 3, 2010. (Sept. 14, 2011) http://green.blogs.nytimes.com/2010/09/03/vietnam-raids-restaurants-selling-illegal-exotic-meats/
- ThinkQuest. "History of Rabbits in Australia." 2010. (Sept. 14, 2011) http://library.thinkquest.org/03oct/00128/en/rabbits/history.htm
- United States Environmental Protection Agency. "Major Crops Grown in the United States." Sept. 10, 2009. (Sept. 14, 2011) http://www.epa.gov/agriculture/ag101/cropmajor.html
- United States Environmental Protection Agency. "Summary of the EPA Municipal Solid Waste Program." Sept. 7, 2011. (Sept. 14, 2011) http://www.epa.gov/reg3wcmd/solidwastesummary.htm
- VanEngelsdorp, Dennis. "A survey of managed honey bee colony losses in the USA, fall 2009 to winter 2010." Journal of Apicultural Research. Nov. 19, 2010. (Sept. 14, 2011) http://ento.psu.edu/publications/vanenegelsdorp%20et%20al%202011.pdf
- Waste Online. "Paper recycling information sheet." January 2006. (Sept. 14, 2011) http://www.wasteonline.org.uk/resources/InformationSheets/paper.htm
- Wonders, Ryann. "The Benefits of Bats." Carleton College. December 2005. (Sept. 14, 2011) http://apps.carleton.edu/curricular/ents/resources/stu_projects/global_change_2000/bats/
- The World Bank. "Roads and the Environment: A Handbook." 2008. (Sept. 14, 2011) http://siteresources.worldbank.org/INTTRANSPORT/Resources/336291-1107880869673/chap_16.pdf
- Young People's Trust for the Environment. "Biodiversity." 2010. (Sept. 14, 2011) http://www.ypte.org.uk/environmental/biodiversity/2