At least 28% of all species on Earth face the possibility of extinction. That’s according to assessments by the International Union for Conservation of Nature (IUCN). IUCN’s Red List of Threatened Species breaks down the risk by taxa.
These percentages are only of assessed species, of which there are more than 142,000. That’s a drop in the ocean when you realize there are an estimated 8.7 million species on Earth. We don’t actually know how many species are at risk.
Humans pose the biggest threat to biodiversity, but we are also the only species that can help address widescale mass extinction. It’s not enough to talk about this crisis. We must focus on solutions. Through innovative conservation strategies, we can reverse the risk and save species.
Cycads have been around since before the dinosaurs. They are the oldest living seed plants. Yet despite surviving multiple global extinction events, 63% of these plants are now at risk of being wiped out. Cycads represent the most threatened plant species on Earth. In addition to serving as host plants for numerous invertebrates, such as beetles, humans also use the plants for food and cultural events.
41% of amphibian species are on the brink of extinction. The Amphibian Specialist Group says they are the most threatened vertebrate class on Earth. Threats to frogs, toads, salamanders and caecilians include habitat loss and degradation, pollution, disease, invasive species, use and trade, and climate change.
More than a third (37.5%) of all sharks, rays and chimaeras are threatened with extinction. A 2021 publication lists overfishing as the primary threat facing chondrichthyan fishes. Other threats include habitat degradation, pollution and climate change.
Of the 615 known conifer species, 211 are at risk of extinction. The IUCN Conifer Specialist Group says the main threats to conifers include agriculture and forestry, climate change and logging.
IUCN says one-third of reef corals face the threat of extinction. These reefs provide homes for 25% of marine life, but climate change, destructive fishing practices, pollution and habitat degradation pose a serious threat to this biodiversity.
28% of selected crustaceans are at risk of extinction. This group includes lobsters, freshwater crabs, freshwater crayfishes and freshwater shrimps. The main threats include pollution, harvesting and habitat loss.
Of 5,883 assessed species of mammals, 26% are at risk of extinction. Primates and rodents make up the bulk of the Critically Endangered mammalian species.
21% of the world’s reptiles are at risk of extinction. This class of animals includes turtles, snakes, lizards, crocodilians and tuatara. The biggest threats facing reptiles are harvesting, agriculture, habitat destruction and invasive species.
The current mass extinction event isn’t the first in Earth’s history. We’re living in the 6th mass extinction. But unlike previous events, humans are responsible for this one. Yet hope remains. “If working apart we’re a force powerful enough to destabilize our planet, surely, working together, we are powerful enough to save it,” said Sir David Attenborough.
IUCN Red List Assessors – including some staff members at the Global Center for Species Survival – look at a variety of direct threats when determining extinction risk. Threats include:
Residential and commercial development threats include housing developments, urban areas, commercial areas, industrial areas, tourism and recreation areas.
Agriculture threats include annual and perennial non-timber crops, wood and pulp plantations, and livestock farming and ranching. Aquaculture threats include marine and freshwater aquaculture.
Energy production and mining threats include oil and gas drilling, mining and quarrying, and renewable energy.
Transportation and service corridor threats include roads, railroads, utility and service lines, shipping lanes and flight paths.
Biological resource use threats include hunting and trapping animals, gathering plants, logging, fishing and harvesting aquatic resources.
Human intrusions and disturbance threats include recreational activities, war, civil unrest and military exercises.
Natural system modification threats include fire and fire suppression, dams and water management/use, and other ecosystem modifications.
Invasive species threats include problematic non-native and native species, introduced genetic material, and disease threats from native and introduced diseases and viruses.
Pollution threats include wastewater, industrial and military effluents, agriculture and forestry effluents, garbage and solid waste, air-borne pollutants and excess energy.
Geologic event threats include volcanic eruptions, earthquakes, tsunamis, avalanches and landslides.
Climate change threats include habitat shifting and alteration, droughts, temperature extremes, storms and flooding.
Learn how conservation works to reduce threats to species and reverse extinction trends.