About 1.75 million species of plants, animals, and microorganisms have been identified out of the 13 million total species estimated by scientists (Sustaining, 2000). The services these species provide contribute to the delicately-running natural cycles that help make earth habitable to humans and contribute to our way of life in many ways, from providing us food and pharmaceuticals to helping reduce the impact of natural disasters such as floods. Biodiversity is positively correlated with ecosystem productivity by a mechanism known as functional complementarity, which states that the more species there are, the more niches are occupied, and thus the greater productivity of the ecosystem (Wilby & Hector, 2008). Thus, if humans want to continue benefiting from the abundance of these natural goods and services, the biodiversity that establishes them must be preserved. The United Nations Convention on Biological Diversity, notes that, "at least 40 per cent of the world's economy and 80 per cent of the needs of the poor are derived from biological resources" ("Convention", 2011). Saving this biodiversity is in the self-interest of the human race.
All organisms need food to survive. Although humans consume only a small number of species, these species depend on many, many others in order to thrive. Additionally, the agricultural processes of intercropping and crop rotations have been used for thousands of years to increase productivity. This requires a diverse array of species. Additionally, crop populations that have genetic variation have a much greater chance of surviving disasters like disease. When a certain strain of spinach is infected with the bacterium E. coli, the entire yield must be disposed of (FDA Statement, 2006). Pests have the ability to survive pesticides because non-resistant organisms are naturally selected against. Beacuse of this, new pesticides and herbicides must constantly be created. More and more pests are becoming resistant to pesticides at an increasing rate, faster than controls can be developed (Bellinger 1996). However, many organic farmers have found that pests are always effectively controlled by their natural predators. In this way, biodiversity contributes to agriculture both by increasing productivity and protecting yield.
The environment also provides medicines, both of the traditional and modern variety. Humans harvest an estimated 50-70,000 plant species worldwide ("How does," 2011). Some tribes in South Africa use the organs or fats from 32 different animals to cure a variety of illnesses ("Animal Cures", 2011). On the other side, 25 percent of Western pharmaceuticals are derived from the Amazon Rainforest, but less than 1 percent of Amazonian trees have been tested ("Rainforest Facts", 2010). As more and more of the Amazon is destroyed, hundreds of potential cures could also disappear. Even those drugs that can be synthesized in the laboratory are often discovered in natural sources first. For instance, conotoxins are a vast group of over 50,000 different kinds of venom that are typically used by cone shells in order to paralyze and kill their preys. However, scientists have recently identified more than 100 different conotoxins that have the potential to become treatments for various diseases as far-ranging as arthritis and cancer ("The Venom Cure", 2011).
Furthermore, the environment provides wood for paper, construction, and fuels. Some of this fuel comes from nonrenewable sources. This relies on the carbon cycle, in which carbon is transferred through the biosphere from the atmosphere to photosynthesis to decomposition. Natural fibers are also useful for a variety of products, namely fabrics. Cotton is the most common material found in our clothing. It has been cultivated for 7,000 years and, in modern days, can be conveniently mixed with other fibers for special characteristics (Cotton, 2008). Biodiversity provides much of the basic necessities of food, water, clothing, and shelter.
The value of natural goods and services is estimated to be about 33 USD trillion per year (Costanza, 1997). For reference, in 2010 the GDP of the United States was only 14.66 trillion USD and the GDP of the European Union was a comparable 14.82 trillion USD (The World Factbook, 2011).
Biodiversity helps to moderate the elements, reducing utility bills and preventing large-scale damage. According to the conservation organization American Forests, "depending on location, species, size, and condition, shade from trees can reduce utility bills for air conditioning in residential and commercial buildings by 15 to 50 percent" ("Clean Air", 2011). Floods and droughts can be effectively managed by wetlands and forests, which absorb and provide water. In Vietnam, planting and protecting 12,000 hectares of mangroves costs 1.1 million USD, but annually saves 7.3 million USD in dyke expenditures (Economics of Ecosystems, 2009). Wetlands and forests also function in the detoxification of water, saving billions of dollars in water purification. In the Catskills watershed in New York, the maintenance of water purification services cost 305 billion USD - which is 507 billion USD less than the estimated cost of a filtration plant (Economics of Ecosystems, 2009). The natural environment can also protect from winds, prevent soil and coastal erosion, and moderate temperatures. The oceans, for instance, play a major role in temperature and climate regulation due to the great heat capacity of water. El Niño and La Niña, periodical warming and cooling of the eastern tropical Pacific, contribute to shifts in rainfall and climate patterns across the globe ("El Niño," 1994). Predictions of these patterns, which become increasingly inaccurate as human activites cause climate change, could save as much as 8 billion USD in damages ("Economic Impacts", 1994).
Large amounts of biodiversity also create many different jobs, from farmers to park rangers. The pharmaceutical and personal care markets, which rely on chemicals extracted from diverse life forms, together raked in 652 billion USD for the U.S. in 2006 (Economics of Ecosystems, 2009). The International Union for the Conservation of Nature estimates that coral reefs provide food, storm protection, and jobs for 500 million people worldwide. These resources alone have been estimated to value around 375 billion USD a year ("A Fortune", 2009). The protected areas of the Amazon bring in about three times as much money as would extensive cattle ranching, the most likely alternative use of the areas (Economics of Ecosystems, 2009). It has also been estimated that designating 20-30 percent of the oceans as Marine Protected Areas could create 1 million jobs and still sustain a marine fish catch worth 70-80 USD billion annually (Economics of Ecosystems, 2009). Ecotourism contributes about 77 billion USD to the global market. As such, keeping the areas that tourists visit for their beauty is critical. A study done in 2005 found that over 2/3 of American and Australian travelers and 90 percent of British travelers consider active environmental protection as part of a hotel's responsibility (Economics of Ecosystems, 2009).
The most recognizable benefit of biodiversity is the aesthetically pleasing aspect. A huge variety of plants are used in decorating homes and other buildings. This also can be a major attraction for tourists, bringing in profits and creating jobs. About 1.6 million tourists visit the Great Barrier Reef each year ("Great Barrier", 2011). Moreover, many intellectuals turn to the environment for inspiration, such as impressionist artists. The environment and society have been connected since the beginning of civilization. Animals have been domesticated for both work and play; there is evidence of pet dogs from 12,000 years ago in Iraq ("History", 2011). Many cultures have deep, traditional connections to the earth, ranging from medicines to tribal ceremonies.
Biodiversity is also greatly important for research. Examples of biodiversity-dependent research include bioengineering organs from tissues that can be transplanted in a patient's body, searching for new medicines to cure cancer, and improving human nutrition. The possibilities are nearly endless. For instance, scientists have discovered that they can make spider silk tougher by inserting metals into it (Timmer, 2009). Research like this has the potential to develop new technologies. While there is much still to be discovered, it is evident that humans cannot continue forward without natural goods and services. In a joint lab between the Massachusetts Institute of Technology and Woods Hole Oceanographic Institute, researchers created an underwater robot that can make sharp turns and back flips in a chaotic environment. This robot could be used to study turbulent coastlines. The leading researcher on the project, Stephen Lichet, accomplished this by analyzing the movement of a 500-pound sea turtle in the New England Aquarium (Stanway, 2009). Society has reached a point where it can progress no further without understanding the complex natural systems of the Earth.
In conclusion, biodiversity is essential for a wide array of natural systems to exist and thrive. In the environment, everything is connected. One break in the chain can cause a major malfunction and halt these processes. To preserve those most important to us, we must preserve them all, for the parts must be preserved to preserve the whole.