This question was asked to the public in Sweden, Norway, Finland, Denmark and the UK in the Sustainable Development Misconception Study 2020
In December 2020 Gapminder launches a brand new service for upgrading your worldview, where you will be able to take this (and many other) tests and become certified gapm.io/upgrader
Biologists have evaluated the status of more than 120,000 plants and animals. How many are endangered or threatened?
a) Around 30%
b) Around 60%
b) Around 90%
Around 30% of all evaluated species are threatened or endangered.
Most of nature is not threatened (yet)
If you believed most of nature was threatened already, we think it’s useful for you to realize that two thirds of all animals and plants are NOT threatened, yet. One third is terribly high, but it’s still possible to reverse the trend towards mass extinction. A lot of conservation work is successful and more is needed.
Every year, biologists across the world study the situation of plants and animals and they publish their findings on the RedList where you can track the status of more than 120,000 species! That’s a lot, but it’s actually just 6% of all known species in the world, and nobody knows what share of all existing species are known. New assessments of more species are added every year and when they are, roughly the same proportion is listed as threatened or endangered – around 27%.
We have no intention of trivializing the fact that one third of nature is at risk already. But most people thought the situation was even worse, and we believe that may cause resignation, as people lose their hope. There’s still a lot we can and should do to reverse the trend towards mass extinction.
Of the total estimated species, only 6% have been evaluated by the Red List, meaning we can’t know for sure what the number would be if all known species were evaluated, and we absolutely don’t know what the number is for all the species that are not yet discovered. But we can clearly see that the public are wrong about the rate of threatened species among those that are evaluated.
As of October 2020, the International Union for Conservation of Nature’s Red List  had assessed the threatened status of 120,372 species, and of those 32,441 were classed as threatened (critically endangered, endangered or vulnerable), a percentage of 27%. Those numbers also include fungi and protists, which are neither plants nor animals.
The Red List uses a variety of criteria to assess the threatened state of an animal, and focuses on the worst-case scenario, potentially overestimating the level of threat. The criteria are somewhat subjective and the decisions are secretive and in some cases there are political motivations to listing a species as more or less threatened than it is. Also, we humans tend to focus on where the problems are, so potentially when evaluating species for the Red List, those that are most endangered are being evaluated first, which would lead to that 27% might be an overestimation, but nobody knows for sure.
Even if different experts would assess the status of the same species differently, the 120,000 is such a large number that the disagreements would probably go in both directions. And even if 27% is probably an overestimation, it is definitely “more right” than the other options of this question, which was confirmed by four independent biologists who we asked for feedback.
Source 1 – IUCN Red List, Table 1a