What is biodiversity?

Earth is home to millions of discovered species of plants and animals with many more yet to be known. They all play vital roles in each other, their ecosystems, and the planet's overall health and they make up what is known as biological diversity.

But what exactly is biodiversity? It's a shortened version of two scientific terms – biological diversity. Essentially, all it means is having a variety of living things. There are three main levels of biodiversity scientists typically refer to, according to the Smithsonian, including species, genetic and ecosystem diversity. Under these categories, researchers are looking to identify how many and what kind of species are around, what the genetic makeup of those individual species are and passing down to generations and what species populations are in various environments, such as waterways and forests.

"These levels cannot be separated," the Smithsonian says. "Each is important, interacting with and influencing others. Changes at one changes at other levels."

Why is biodiversity important?

A species' ability to thrive isn't only essential for its survival, but in many cases, for the survival of others as well. One of the clearest examples of this is bumblebees. According to the U.S. Department of Agriculture, there are 49 species of bumblebees across the U.S., and they all will go flower-to-flower, picking up nectar and pollen as they go. Not only does that help feed individual bees, but the transporting of the nectar and pollen also helps plant species thrive.

However, studies have found that climate change is threatening their survival, with researchers finding the likelihood of a bumblebee population surviving has declined by an average of 30% within a single generation of humans.

Honeybees also serve a vital role in biodiversity. The USDA says they pollinate $15 billion worth of crops every year, helping support life for more than 130 agricultural products. The honey they produce, which humans have grown to love and enjoy, is also worth millions.

What is biodiversity loss?

As important as biodiversity is, it's come under significant threat. In 2019, a United Nations report found that roughly 1 million plant and animal species could be threatened with extinction, while a newer report found an even more dire state – up to 6 million species extinct over the next 50 years.

"Major direct threats to biodiversity include habitat loss and fragmentation, unsustainable resource use, invasive species, pollution, and global climate change," the American Museum of Natural History says. "The underlying causes of biodiversity loss, such as a growing human population and overconsumption are often complex and stem from many interrelated factors."

How many species are there?

Scientists estimate that there are roughly 8.7 million species of plants, animals, fungi, and other organisms on Earth, including roughly 2.2 million species that live in the world's oceans. But even that number is low for the true amount of life on the planet.

"In spite of 250 years of taxonomic classification and over 1.2 million species already catalogued in a central database, our results suggest that some 86% of existing species on Earth and 91% of species in the ocean still await description," researchers said in a 2011 study. "Renewed interest in further exploration and taxonomy is required if this significant gap in our knowledge of life on Earth is to be closed."

But new species are constantly being discovered. In 2023, scientists at London's Natural History Museum say they've uncovered 815 new species, from geckos to algae to swamp eels. And that's just one group of scientists.

Thousands of other species have been discovered since Earth Day 2023, including more than 5,500 species in a single area, the Clarion-Clipperton Zone between Hawaii and Mexico. Researchers have also found new species of hedgehogs, a deepwater catshark, an "electrical" blue tarantula, and a deep-sea octopus.

"The bad news, however, is that biodiversity is declining," says the International Union for Conservation of Nature (IUNC) Red List, the world's most comprehensive list of species conservation status.

The Red List holds more than 157,100 species, including 44,000 the group says are threatened with extinction – more than a quarter of all the species the IUCN has assessed.

How to help and protect biodiversity

Even though species decline continues to be a serious ongoing issue, there are things that everyone can do to help what's happening in their own backyard.

If you have a garden, for example, opting for native plants and wildflowers can be a huge boost for the local ecosystem. Native plants, which are those that grow naturally in a region, are vital to an area's biological web, help reduce the amount of needed fertilizers and pesticides and provide ample pollinating opportunities. According to the National Audobon Society, they also require less water to maintain and can help store greenhouse gases, which are a key driver of climate change when they are in the atmosphere.

If you enjoy hiking or spending time outdoors, it's also key to respect nature. Sticking to walking paths and trails isn't just for your safety but for that of the species around you. Constantly disrupting habitats or walking on plant life can tarnish an ecosystem.

Reducing and reusing materials is also key, as landfills and pollution can be detrimental to life on Earth, especially marine life. Consider buying items second-hand and instead of throwing away old clothes or things around the house, find a way to repurpose them, sell them or donate them.

Essentially, it's all about taking care of the home outside of your home.

"It is within our power to change our actions to help ensure the survival of species and the health and integrity of ecological systems," the American Museum of Natural History says. "...While we might not be able to prevent all negative human impacts on biodiversity, with knowledge we can work to change the direction and shape of our effects on the rest of life on Earth."

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