Context: The latest update to the International Union for Conservation of Nature (IUCN) Red List of Threatened Species shows that more and more species assessed are being threatened with extinction.

• The IUCN Red List assesses 1,05,732 species. The current update breaks the 1,00,000 species barrier, making it the largest such assessment of species.
• According to the new updated list, 28,338 species are threatened with extinction. 

Key findings:

1. Nature is declining globally at rates unprecedented in human history — and the rate of species extinction is accelerating, with grave impacts on people around the world now likely.
2. According to the global assessment, one million animal and plant species are under extinction. Moreover, thousands of these would extinct within decades.
3. The new list brings out an alarming rate of decline of freshwater and deep-sea species. For example, over 50 per cent of Japan’s endemic freshwater fishes are under extinction. The main drivers of this decline are the loss of free-flowing rivers and increasing agricultural and urban pollution.

About IUCN red list of threatened species:

• The IUCN Red List of Threatened Species is the world’s most comprehensive inventory of the global conservation status of plant and animal species.
• It uses a set of quantitative criteria to evaluate the extinction risk of thousands of species. These criteria are relevant to most species and all regions of the world. With its strong scientific base, The IUCN Red List is recognized as the most authoritative guide to the status of biological diversity.

The IUCN Red List Categories:

The IUCN Red List Categories define the extinction risk of species assessed. Nine categories extend from NE (Not Evaluated) to EX (Extinct).

Critically Endangered (CR), Endangered (EN) and Vulnerable (VU) species are considered to be threatened with extinction.

The IUCN system uses a set of five quantitative criteria to assess the extinction risk of a given species. In general, these criteria consider:

• The rate of population decline.
• The geographic range.
• Whether the species already possesses a small population size.
• Whether the species is very small or lives in a restricted area.
• Whether the results of a quantitative analysis indicate a high probability of extinction in the wild.

Significance:

The IUCN Red List brings into focus the ongoing decline of Earth’s biodiversity and the influence humans have on life on the planet. It provides a globally accepted standard with which to measure the conservation status of species over time.

Scientists can analyze the percentage of species in a given category and how these percentages change over time; they can also analyze the threats and conservation measures that underpin the observed trends.