We humans have come a long way in gaining our independence from the whims of Mother Nature. We've learned how to build shelters and clothe ourselves. Through agriculture and irrigation, we can control our own food supply. We've built schools, hospitals, computers, automobiles, airplanes and space shuttles. So what's the big deal if a bunch of plants, animals and simple organisms die out?
Here's the problem with the loss of biodiversity: The Earth functions like an incredibly complex machine, and there don't appear to be any unnecessary parts. Each species -- from the lowliest microbe to humans -- plays a part in keeping the planet running smoothly. In this sense, each part is related. If a lot of those parts suddenly vanish, then the machine that is Earth can't function properly.
For example, the crops that we grow though our clever use of agriculture are enabled by the nitrogen present in the soil. This nitrogen nourishes and strengthens our crops. But where does it come from? Worms, bacteria and other life found within the soil love to decompose vegetation. When they eat, these organisms produce nitrogen as waste, which crops really love. This is also how nutrient-rich compost is made. If these bacteria species were killed off, then our crops would not grow properly.
This holds true for ocean ecosystems too. The ocean -- along with land-based plant vegetation -- plays a major role in absorbing carbon dioxide -- a gas that humans can't breathe. The ocean doesn't absorb this CO2 on its own. It relies on organisms like phytoplankton -- microscopic aquatic plant life -- to absorb the CO2. Loss of phytoplankton means we lose adequate levels of breathable air.
Even some of our own modern advances in technology depend on nature. Modern medicine owes much to the properties found naturally in plants and bacteria. Medications like painkillers, penicillin and inoculations are based on natural organisms. The structure of these living things has been analyzed and synthesized to produce some medications, but others -- like antibiotics -- still use the actual organisms. In total, this accounts for one-quarter of all the prescription drugs we use [source: David Suzuki Foundation]. What's more, if the Earth suddenly lost its hearty biodiversity, drugs that have yet to be discovered would also be lost.
Even if we humans could find a way to overcome a catastrophic loss of biodiversity, our existence on Earth would certainly be changed. There's a very important economic aspect to biodiversity as well. In 1997, Cornell University scientists tallied the dollar value of all the services provided for humanity by life on Earth. Everything from ecotourism and pollination to soil formation and pharmaceuticals was taken into account. The total for services provided to humanity by Mother Nature came to $2.9 trillion per year (another study concluded the total was $33 trillion) [source: Science Daily].
These services would still be required, with or without a diverse global ecosystem. As the resources that provided these services (like nitrogen produced by worms) dwindled, humans would have to replace them in order to survive. Stores of things like nitrogen for soil and medicine for the sick would quickly and significantly increase in value. Competition for these dwindling resources would develop, with wealthier and better armed countries inevitably winning. Life, indeed, would change for humanity as a result of a loss of biodiversity. It would quickly get worse.
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