Extinction & Biodiversity

Earth’s ecosystems have evolved for millions of years, resulting in diverse and complex biological communities living in balance with their environment. Since the 16th century, human activity has impacted nature in practically every part of the world, wild plants and animals are at risk of extinction, deforestation and land degradation are causing water scarcity and erosion, and climate change leads to acidification of oceans.

Biodiversity loss is the extinction of species (plant or animal) worldwide, and also the local reduction or loss of species in a certain habitat.

Over the past 50 years, humans have changed ecosystems more rapidly than ever before; 60% of ecosystems are degraded and often over-exploited, and pressures on nature are increasing despite the growing number of responses to tackle biodiversity loss.

Nature and its contributions to people are fundamental to the existence of humans as a species and for our societies and their future development. Nature and its contributions to people are, however, continuing to decline, largely because of human actions. Of 2,493 species assessed in Europe and Central Asia, 13% are included on the Red List of Threatened Species of the International Union for Conservation of Nature (IUCN), which constitutes 6.5% of the total numbermof the species included on the IUCN Red List of Threatened Species, globally.

The biodiversity of an area is literally the number of species, both plant and animal, inhabiting the environment being examined. When a species is no longer found in a region, it is locally extinct. When it is no longer found anywhere, the species is considered extinct.

Species diversity ensures ecosystem resilience, giving ecological communities the scope they need to withstand stress. Thus while conservationists often justifiably focus their efforts on species-rich ecosystems like rainforests and coral reefs — which have a lot to lose — a comprehensive strategy for saving biodiversity must also include habitat types with fewer species, like grasslands, tundra, and polar seas — for which any loss could be irreversibly devastating. And while much concern over extinction focuses on globally lost species, most of biodiversity's benefits take place at a local level, and conserving local populations is the only way to ensure genetic diversity critical for a species' long-term survival.

How  many species? 
To date, about 1.5 million species have been formally described in the scientific literature, most of them insects. Proportionally, bacteria comprise less than 1% of all described species.

Scientists generally agree that many more species exist than are formally described, but they disagree about how many there really are. Some studies have estimated 2 million or fewer, whereas others suggest as many as 12 million (one recent study even suggested the planet could be home to a trillion species).

In a new paper published in The Quarterly Review of Biology, researchers from the University of Arizona have estimated that there are roughly 2 billion living species on Earth, over a thousand times more than the current number of described species.

What is happening to life on earth? What are the pressures affecting biological diversity globally, and what can be done to stop its decline?

First published 20 years ago, for two decades the Living Planet Index has tracked the state of biodiversity by measuring the population abundance of thousands of vertebrate species around the world. The latest index shows an overall decline of 60% in population sizes between 1970 and 2014. 

Current rates of species extinction are 100 to 1,000 times higher than the background rate, also known as the standard rate of extinction in Earth’s history before human pressure became a prominent factor. Species population declines are especially pronounced in the tropics, with South and Central America suffering the most dramatic decline, an 89% loss compared to 1970. 

Freshwater species numbers have also declined with a focused Freshwater Index showing an 83% decline since 1970. To put these trends in a broader context, this chapter also explores three other indicators measuring changes in species distribution, extinction risk and community composition. All these results paint the same picture – that of continuing biodiversity loss.

Why biodiversity matters
Everything that has built modern human society, with its benefits and luxuries, is provided by nature – and we will continue to need these natural resources to survive and thrive. Increasingly, research demonstrates nature’s incalculable importance to our health, wealth, food and security. What future benefits might we discover in the millions of species yet to be described, let alone studied? As we better understand our reliance on natural systems it’s clear that nature is not just a ‘nice to have’. 

Our planet’s diverse, thriving ecosystems may seem like permanent fixtures, but they’re actually vulnerable to collapse. Jungles can become deserts, and reefs can become lifeless rocks. What makes one ecosystem strong and another weak in the face of change? Kim Preshoff details why the answer, to a large extent, is biodiversity.

What's clear is that many thousands of species are at risk of disappearing forever in the coming decades.

Amphibians
No group of animals has a higher rate of endangerment than amphibians. Scientists estimate that a third or more of all the roughly 6,300 known species of amphibians are at risk of extinction. The current amphibian extinction rate may range from 25,039 to 45,474 times the background extinction rate.

Frogs, toads, and salamanders are disappearing because of habitat loss, water and air pollution, climate change, ultraviolet light exposure, introduced exotic species, and disease. Because of their sensitivity to environmental changes, vanishing amphibians should be viewed as the canary in the global coal mine, signaling subtle yet radical ecosystem changes that could ultimately claim many other species, including humans.

Invertebrates  
Invertebrates, from butterflies to mollusks to earthworms to corals, are vastly diverse — and though no one knows just how many invertebrate species exist, they're estimated to account for about 97 percent of the total species of animals on Earth. Of the 1.3 million known invertebrate species, the IUCN has evaluated about 9,526 species, with about 30 percent of the species evaluated at risk of extinction. Freshwater invertebrates are severely threatened by water pollution, groundwater withdrawal, and water projects, while a large number of invertebrates of notable scientific significance have become either endangered or extinct due to deforestation, especially because of the rapid destruction of tropical rainforests. In the ocean, reef-building corals are declining at an alarming rate: 2008's first-ever comprehensive global assessment of these animals revealed that a third of reef-building corals are threatened

Plants
Through photosynthesis, plants provide the oxygen we breathe and the food we eat and are thus the foundation of most life on Earth. They're also the source of a majority of medicines in use today. Of the more than 300,000 known species of plants, the IUCN has evaluated only 12,914 species, finding that about 68 percent of evaluated plant species are threatened with extinction.

Unlike animals, plants can't readily move as their habitat is destroyed, making them particularly vulnerable to extinction. Indeed, one study found that habitat destruction leads to an “extinction debt,” whereby plants that appear dominant will disappear over time because they aren't able to disperse to new habitat patches. Global warming is likely to substantially exacerbate this problem. Already, scientists say, warming temperatures are causing quick and dramatic changes in the range and distribution of plants around the world. With plants making up the backbone of ecosystems and the base of the food chain, that's very bad news for all species, which depend on plants for food, shelter, and survival.

Dr. Elizabeth Hadly of Stanford University reveals how human activities have caused the extinctions of many species in the past and the present. Human population growth is driving habitat destruction and climate change, both direct threats to biodiversity.

Reptiles 
Globally, 21 percent of the total evaluated reptiles in the world are deemed endangered or vulnerable to extinction by the IUCN — 594 species — while in the United States, 32 reptile species are at risk, about 9 percent of the total. Island reptile species have been dealt the hardest blow, with at least 28 island reptiles having died out since 1600. But scientists say that island-style extinctions are creeping onto the mainlands because human activities fragment continental habitats, creating “virtual islands” as they isolate species from one another, preventing interbreeding and hindering populations' health. The main threats to reptiles are habitat destruction and the invasion of nonnative species, which prey on reptiles and compete with them for habitat and food.

Agriculture
More than 90 percent of crop varieties have disappeared from farmers’ fields; half of the breeds of many domestic animals have been lost. In fisheries, all the world’s 17 main fishing grounds are now being fished at or above their sustainable limits, with many fish populations effectively becoming extinct. Loss of forest cover, coastal wetlands, other ‘wild’ uncultivated areas, and the destruction of the aquatic environment exacerbate the genetic erosion of agrobiodiversity.

Of some 6,000 plant species cultivated for food, fewer than 200 contribute substantially to global food output, and only nine account for 66 percent of total crop production.

The world’s livestock production is based on about 40 animal species, with only a handful providing the vast majority of meat, milk and eggs. Of the 7,745 local (occurring in one country) breeds of livestock reported globally, 26 percent are at risk of extinction.

Nearly a third of fish stocks are overfished, more than half have reached their sustainable limit.

Information from the 91 reporting countries reveals that wild food species and many species that contribute to ecosystem services that are vital to food and agriculture, including pollinators, soil organisms and natural enemies of pests, are rapidly disappearing.

For example, countries report that 24 percent of nearly 4,000 wild food species – mainly plants, fish and mammals - are decreasing in abundance. But the proportion of wild foods in decline is likely to be even greater as the state of more than half of the reported wild food species is unknown.

From desert to Grasslands 
A fifth of the land on our planet is covered by desert. The driest of all is the Atacama in South America. There are places there where rain has never been recorded. Deserts may to appear to be barren and empty, but they are of crucial importance to life. For those that can overcome their challenges, they provide a vital refuge. 

Species that live there, the Socotran Cormorants, currently 50.000 of them, which have decreased 25% of their total population - can breed safely in the desert.

Deserts cannot support large numbers of animals the year round, and even those specially adapted to these conditions can only survive in small numbers. But on very special occasions, deserts are transformed. Once in a decade there may be a cloudburst. A single one can turn the desert green. 

In Southern California the change is visible from space. Hundreds of square kilometers suddenly bloom. If such transformations become regular, a new habitat may develop. Grasslands. One of our planet’s most productive landscapes. 

They support the greatest aggregations of large animals on Earth. The Serengeti sustains herds of over a million wildebeest. They follow the rains to crop the newly sprung grass. These vast herds attract predators, like the cheetah. The regulation of wildebeest by the cheetah can continue because the Serengeti is protected, and has been for over 65 years. But the Serengeti is an exception.

Across the planet, space for grasslands has been steadily disappearing. 

A hundred and eighty years ago, herds of bison, millions strong, grazed the Great Plains of North America. They roamed across a prairie a hundred times larger than the Serengeti. This was the true wild west. Today, most of the prairie is silent. Humans slaughtered the great herds. Less than 30.000 wild bison remain, and 90 percent of the prairie has been lost, most of it to agriculture.

What we eat, and how we produce it, will determine the future of our planet’s grasslands.

Forests 
The tropical forest/rain forest is the richest habitat on earth. Exactly how many species rain forests contain is unknown, but it runs into millions. And new ones are discovered every week. Although they cover just seven percent of the world’s land area, jungles play a vital role in the health of the planet.  

Main drivers of species loss 

There are a number of issues threatening our planet's biodiversity, from climate change to invasive species. Below, we discuss some of the biggest threats facing biodiversity today, as well as what the world can do (and is doing) to keep them in check.

How do humans negatively affect biodiversity? Our actions in a given environment cause problems directly and indirectly.

1. Climate change
Changes in climate throughout our planet's history have, of course, altered life on Earth in the long run — ecosystems have come and gone and species routinely go extinct.

But rapid, manmade climate change speeds up the process, without affording ecosystems and species the time to adapt. For example, rising ocean temperatures and diminishing Arctic sea ice affects marine biodiversity and can shift vegetation zones, having global implications.

Overall, climate is a major factor in the distribution of species across the globe; climate change forces them to adjust. But many are not able to cope, causing them to die out.

2. Deforestation and habitat loss
Deforestation is a direct cause of extinction and loss of biodiversity. An estimated 18 million acres of forest are lost each year, due in part to logging and other human practices, destroying the ecosystems on which many species depend.

Tropical rainforests in particular, such as the Amazon, hold a high percentage of the world's known species, yet the regions themselves are in decline due to humans.

3. Overexploitation
Overhunting, overfishing and over-harvesting contribute greatly to the loss of biodiversity, killing off numerous species over the past several hundred years. Poaching and other forms of hunting for profit increase the risk of extinction; the extinction of an apex predator — or, a predator at the top of a food chain — can result in catastrophic consequences for ecosystems.

4. Invasive species
The introduction of non-native species into an ecosystem can threaten endemic wildlife (either as predators or competing for resources), affect human health and upset economies.

5. Pollution
From the burning of fossil fuels (releasing dangerous chemicals into the atmosphere and, in some cases, depleting ozone levels) to dumping 19 billion pounds of plastic into the ocean every year, pollution completely disrupts the Earth's ecosystems. While it may not necessarily cause extinction, pollutants do have the potential to influence species' habits.

For example, acid rain, which is typically caused by the burning of fossil fuels, can acidify smaller bodies of water and soil, negatively affecting the species that live there by changing breeding and feeding habits.

Ecosystems rely on all parts from the smallest bacteria to the largest vertebrate. Everything is interconnected. Some produce oxygen that others breathe. Some provide food for bigger species which in turn become prey for still bigger species. Every living organism has a role to play in maintaining the balance. When you remove one element you change the balance and can ultimately lose far more than that one species.

Although humanity tends to think of itself as being the top of the food chain, it too is dependent on the other elements of the chain. If the lower parts of the chain disappear, the effects will be felt all the way to the top.

The loss of genetic diversity within our global food system has huge implications for its future sustainability. Out of the millions of species and varieties that have been described and recorded by humans, only 30 crops provide 95% of human food energy  needs, and just four of them – rice, wheat, maize and potatoes – provide more than 60%.

This homogenisation of agricultural production has resulted in significant genetic erosion as farmers worldwide have replaced multiple local varieties and landraces with genetically uniform, high-yielding varieties.

Any loss, degradation or relocation of biodiversity can have an impact on human wellbeing, but it can have a particular impact on the wellbeing of poor and marginalised people who are a) often more directly dependent on natural resources and the services nature provides to meet immediate livelihood needs, and b) often unable to afford substitutes in the absence of freely available natural resources and services. There is a lot we don’t know about the impacts of biodiversity loss but the evidence we do have suggests that biodiversity loss will present challenges to the achievement of many development priorities – from health to food security to disaster risk reduction. 

Solutions

Conservationists are desperate for a biodiversity accord that will carry the same weight as the Paris climate agreement. But so far, this subject has received miserably little attention even though many scientists say it poses at least an equal threat to humanity.

The last two major biodiversity agreements – in 2002 and 2010 – have failed to stem the worst loss of life on Earth since the demise of the dinosaurs.

Eight years ago, under the Aichi Biodiversity Targets, nations promised to at least halve the loss of natural habitats, ensure sustainable fishing in all waters, and expand nature reserves from 10% to 17% of the world’s land by 2020. But many nations have fallen behind, and those that have created more protected areas have done little to police them. “Paper reserves” can now be found from Brazil to China.

The issue is also low on the political agenda. Compared to climate summits, few heads of state attend biodiversity talks. Even before Donald Trump, the US refused to ratify the treaty and only sends an observer. Along with the Vatican, it is the only UN state not to participate.

One cause for hope was a convergence of scientific concerns and growing interest from the business community. Last month, the UN’s top climate and biodiversity institutions and scientists held their first joint meeting. They found that nature-based solutions – such as forest protection, tree planting, land restoration and soil management – could provide up to a third of the carbon absorption needed to keep global warming within the Paris agreement parameters. In future the two UN arms of climate and biodiversity should issue joint assessments.

With a few simple habit changes and pro-active actions, you can reduce your adverse impact on the environment and encourage local biodiversity.

1. Help Native Pollinators. Pollinators, are the key to reproduction for most flowering plants which are foundational to the survival of many species on our planet. This is why the criteria of Biodiversity Hotspots gives so much weight to the number of plants in an area. Give pollinators an extra boost in your backyard by: reducing or eliminating the use of pesticides, providing nectar sources by planting a variety of wildflowers and native plants that will bloom throughout the season, leaving logs and rocks in your yard or build bee boxes for native bees to make their home, encouraging your City to stop weed-whacking median strips and sidewalk edges and let native wildflowers grow to create pollinator corridors. Visit the Xerces Society for Invertebrate Conservation to learn more.

2. Reduce or eliminate pesticides and fertilizer. Consider getting rid of your lawn, especially if you live in an arid region. Instead, plant native plants that are well adapted to your area. This will reduce the need to use pesticides and fertilizers. Don’t buy plants from nurseries that use systemic pesticides such as neonictinoids. When applied, they persist in all parts of the plant from the seed to the stem to the blossom and reek havoc on already stressed pollinators. Use organic compost and soil additives instead. Soil health is the best prevention for pest infestations, but if you do get visited by unwanted guests, learn how to care for your plants with organic pest control.

3. Restore habitat in your yard. If you have a yard, consider turning it into a mini-wildlife sanctuary. National Wildlife Federation has a program to help you attract wildlife whether you have a balcony or a 20-acre farm. In a world where habitat loss is the number one cause of biodiversity loss, providing wildlife with water, food, cover, and a place to raise their young can go a long way.

4. Restore habitat in your community. If you don’t have a yard, consider volunteering on an ecological restoration project in your area. Good places to look for volunteer opportunities are land trusts, wildlife foundations, Native Plant Societies, government agencies (e.g. Forest Service, Fish & Wildlife), and environmental organizations. You’ll spend time outdoors and learn about the native plants and animals.

5. Reduce your consumption. This is arguably the action that will have the biggest positive impact on the environment. The more we reduce our demand for new resources, the less habitat will be destroyed to get those resources or the energy to make those products, and the less waste goes into the landfill. Become a minimalist. Most “minimalists” choose to live a simple life to free up their time to do the things they love rather than spending time shopping and repairing stuff. The idea is “Own Less, Live More.” But it’s undeniable that the minimalist lifestyle also greatly benefits the environment.

6. Reuse and recycle. Composting is key here. It reduces the amount of waste going into landfills and the space needed to hold that waste. Look into ways you can use those purchases intended for single-use. Keep up with what is recyclable in your area. As new markets for recycled products open up, even small towns like mine can increase the numbers of items that they are able to collect.

7. Reduce your energy demand. Burning fossil fuels is the number one driver of climate change which is exponentially quickening biodiversity loss by presenting unparalleled challenges to the world’s plants and animals. Start by conserving energy in your home. A Home Energy Audit can help raise your awareness about where you can reduce energy use in your home. Then incorporate renewable energy. Solar,

8. Buy local foods. Buying from your local farmer at a farmer’s market or through a farm stand gives you the ability to find out how your food was grown and make requests for different practices such as no pesticides, or a greater diversity of produce. It’s easier to ask someone you have a relationship with to change their practices than a big corporation.

9. Buy organic foods. While organic certification doesn’t guarantee that your food is 100% free of pesticides, organic growers are held to criteria of minimal pesticide use.

10. Donate to conservation efforts. Species extinction is happening at an unprecedented rate and there never seems to be enough money to save everything. Prioritize your charitable giving to support conservation efforts in the world’s biodiversity hotspots. As James Borrell, a PhD student in Conservation Genetics stated in his article on The Conversation, “We’re likely to get far greater “biodiversity for our buck” on every pound spent abroad, especially if we focus on the world’s poorest developing countries, many of which are in global biodiversity hotspots.” The Unfolding Earth (this website) will soon be listing reputable, vetted organizations that are doing the work needed to protect wildlands, save biodiversity, and support sustainable development in Biodiversity Hotspots.

A video showing how to address biodiversity through Education for Sustainable Development and mobilise teachers, students, researchers and decision-makers to reflect on biodiversity issues and their interdependence with global sustainable development issues.

11. Advocate for Biodiversity.

Educate yourself about the importance of biodiversity and be able to answer the questions, “Why does it matter so much?” and “Why should we make sacrifices to protect it?”

Genetically modified crops pose multiple serious threats to biodiversity. Support the International Union of Concerned Scientists recommendations on GM crops.

Make connections. Get to know wildlife and conservation biologists as well as political activists and community leaders in your area. Use social media to connect with experts and campaigns.

Lobby your government. Sign or create petitions. Support politicians who support measures to protect biodiversity.

Share your message. Talk to your friends in person. Use social media. Start a blog. Speak at local events.

What do you do to maintain biodiversity? By tagging us with #theconsciouschallenge you can share your ideas!

Want to contribute to our Ecological Footprint Bible? Submit us your scientific articles! Mail us at info@theconsciouschallenge.org

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