Our planet is home to an estimated 8.7 million species of plants and animals, of which around 80% are still waiting to be discovered. Together, with an even greater number of microorganisms, these species define the earth’s ecosystems.
Protecting this remarkable diversity of life is about more than scientific discovery and curiosity. Biodiversity remains a primary indicator of our planet’s health and underpins every facet of our society, from our foods and medicines to our cultures to our ability to withstand extreme weather.
But right now, nature is in crisis.
Over the course of history, 99% of all species have gone extinct, so extinctions are hardly a new concept. However, plant and animal species are disappearing hundreds, or thousands, of times faster than at any time in the last 10 million years, and that pace is accelerating. If we fail to curb threats to nature, from habitat destruction to climate change, scientists warn that one million plant and animal species face extinction, many within just decades.
As with so many other issues, we find ourselves on the precipice, but the solutions are also ours for the taking. To solve the nature crisis, we must first understand what biodiversity is all about.
At its essence, biodiversity is an abbreviation of “biological diversity” and can be defined as the variety of life in our natural world. Biodiversity can be measured as the number of different species, including plants, animals, fungi, algae, and microorganisms, that share a certain home region. Biodiversity is a key indicator of the health of an ecosystem. Areas with particularly high levels of biodiversity, like rainforests or coral reefs, are considered biodiversity hot spots and provide habitat to numerous species unique to that specific area.
Rainforests such as the Amazon are hotspots for biodiversity.
Why is biodiversity important?
Thriving biodiversity is necessary for healthy ecosystems, without which we wouldn’t have a secure food supply, clean water, essential medicines, or, ultimately, a habitable climate.
Ecological Importance
Biodiversity improves the stability and resilience of an ecosystem. In theory, more complex ecosystems have more abundant and variable lifeforms and resources, and are thus more likely to contain species with the ability to withstand stressors like drought, disease, or a changing climate.
Say you remove a healthy forest and plant a single monoculture crop in its place, then you have an infestation break out. That infestation is going to be able to completely devastate the entire field. However, in a diverse ecosystem, some species may be affected, but chances are that some of them will be naturally less vulnerable and survive. That allows for the ecosystem to maintain a foothold and bounce back without total destruction.
Biodiversity is also critical for maintaining an ecosystem’s web of codependencies. In every ecosystem, species rely on each other, supplying one another with shelter and food, for instance. When species start to disappear—whether it’s apex predators or the fungi that decompose dead material—the system of checks and balances begins to go away.
Take the example of the sea otter, a keystone species. If sea otter populations decline, populations of one of its primary prey, sea urchins, then explode. Too many urchins can lead the sea kelp grasses, on which the urchins feed, to decline, removing the food and habitat for numerous other species.
Ecosystem Services
The concept of ecosystem services, also known as nature’s contributions to people, describes the various benefits that people derive from nature. Biodiverse lands and waters directly and indirectly contribute to our well-being in many ways, including through these essential functions.
Water filtration
Certain ecosystems have the ability to scrub pollutants out of the environment. Healthy, intact wetlands, for example, sift out sediment, excess nutrients, and harmful chemicals, helping to keep these contaminants out of waterways, drinking water, and the ocean. The value of biodiversity extends to an ecosystem’s smallest members: Bacteria and fungi are adept at decomposing compounds like nitrogen, a common pollutant from agricultural runoff that can lead to aquatic dead zones. A study on how biodiversity serves to buffer natural ecosystems against the impacts of nutrient pollution, revealed that streams with a variety of algae species removed nitrogen 4.5 times faster than those with only a single species of algae.
Flood protection
Healthy soil that’s rich in bacteria, fungi, and bugs is one of the most cost-effective ways to prevent flood damages and protect ecosystems during drought. In fact, for every 1 percent increase in organic matter in the soil, cropland in the United States could store an additional 45 million gallons of water, or the amount of water that flows over Niagara Falls in 150 days. This natural flood protection is even more important as climate change intensifies rainfall events that overflow our farmland, cities, and towns. Scientists find that every dollar invested into floodplain protection saved five dollars in avoided flood damages. Therefore, ecosystem restoration should be a first line of defense against climate-fueled disaster.
Food security
Because of global inequality, much of the world’s population don’t have adequate food and nutrition. And as climate change worsens the impacts of extreme weather and poverty, more people will struggle to put enough healthy and affordable food on their plates.
Contrary to the emphasis on monocultures within industrial agriculture, robust biodiversity can help sustain food production and security. For example, one out of every three bites of food rely on pollinators like bees, birds, and bats, whose populations are in steep decline. And the diversity of plant life above ground improves the diversity of life below ground, in the form of helpful microbes, insects, and fungi in the soil, which in turn boost agricultural output.
But already, losses of biodiversity are increasing our food challenges. For example, 20 percent of U.S. fish stocks are currently overexploited, even though fisheries that diversify their catches can more sustainably provide food. And as of 2019, 23 percent of the world’s agricultural lands were less productive than just five years before, in part due to declines in soil biodiversity and pollinator populations.
Paddy fields in Indonesia are not depending on animal pollination, but lead to biodiversity declines.
Development of medicines
Thousands of important medicines, for example penicillin, morphine, and aspirin, have been developed from the chemical compounds found in nature. According to the World Health Organization, 11 percent of all the world’s essential medicines are derived from flowering plants, and more are developed each year, from anticancer drugs found in Himalayan fungi to pain-relieving compounds derived from chili peppers. As biodiversity is lost, so is the ability to harness nature’s powerful chemical blueprints.
Economic Importance
The value of all the services that healthy ecosystems provide is estimated to be in the hundreds of trillions each year. In turn, the destruction of ecosystems and the loss of biodiversity bring cascading economic costs. That’s why the World Economic Forum listed biodiversity loss as a top economic threat in its Global Risks Report of 2022. One insurance firm, Swiss Re, recently found that while 55 percent of the global economy is dependent on high-functioning biodiversity and ecosystem services, one-fifth of the world’s countries are at risk of having their ecosystems collapse.
The loss of coral reefs, for example, decimates tourism economies, reduces natural storm surge protection, and means less food and shelter for the fish that many communities depend on for food. And ecosystem destruction that eats away at our natural carbon sinks, like when rainforests or boreal forests are logged, is especially damaging. While the climate crisis represents a nearly incalculable bill, some suggest that it will cost the global economy $23 trillion annually by 2050, a steep price to pay for commodities like the toilet paper made from those old-growth forests.
Social Importance
Species are also integral to religious, cultural, and national identities. All major religions include elements of nature, and 231 species are formally used as national symbols in 142 countries. Unfortunately, more than one-third of those species are threatened, but the bald eagle and American bison are examples of conservation successes because of their role as national symbols. Ecosystems such as parks and other protected areas also provide recreation and a knowledge resource for visitors, and biodiversity is a frequent source of inspiration for artists and designers.
The influence of biodiversity in society goes deep. Nature guides many of our cultural practices and religious beliefs. It fuels our intellectual and artistic pursuits. It shapes our sense of place. Nature offers us a means of experiencing joy, adventure, and awe. That’s why so many of us are ethically compelled to limit harm to wildlife, and we feel a sense of loss as species go extinct.
The famous naval officer and oceanographer Jacques Cousteau once said that “People protect what they love”, a phrase that describes well one of the main issues in conservation. However, even of you don´t love nature enough to protect it, there are evidently more than enough reasons to care about biodiversity.
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