The "health" of life on Earth: the numbers of population decline according to WWF
In November, WWF and Zoological Society of London - ZSL released a report, Living Planet Report 2022, has sounded a wake-up call that is impossible to ignore for the health of life on earth. Among the many data points, one of the most impactful is Living Planet Index, which shows the average change in the abundance of vertebrate populations.
From 1970 to the present, the numbers are mostly in decline: in fact, we are talking about -69%. We are not talking about extinct species, nor about the quantity of animals in absolute terms, but only in the number of populations of certain species surveyed.
All together, these figures give us a situation that is heading towards no return. There is still much to be done to maintain and safeguard our world: these numbers should not frighten us, but serve as a warning to make us work even harder for the good of our planet.
The "health" of life on Earth: the numbers of the population decline according to WWF
In November, WWF and the Zoological Society of London - ZSL released a report, the Living Planet Report 2022, sounding a wake-up call that cannot be ignored for the health of life on Earth. Among the many figures, one of the most impactful is the Living Planet Index, which shows the average change in the abundance of vertebrate populations. From 1970 to the present, the numbers are mostly down: in fact, we are talking about -69%. We are not talking about extinct species, nor about the quantity of animals in absolute terms, but only in the number of populations of certain species surveyed. All together, these data give us a situation that is heading towards no return. There is still much to be done to maintain and safeguard our world: these numbers should not frighten us, but serve as a warning to make us work even harder for the good of our planet.
The Living Planet Index
Specifically, it is an indicator of the state of biodiversity on the planet. It is based on vertebrate populations, i.e. mammals, birds, fish, reptiles and amphibians. The total species considered are 5230, for 31,821 populations. The global decline in November 2022 was 69% compared to 1970 estimates. This as variety and quantity within individual populations, is not the decline in the number of total animals on the planet. We will try to be more specific and give some general examples. The numbers, as they say, speak for themselves.
Examples with gorilla and pink dolphin
To give a few quick examples, in order to make the numbers better understood, here are two declining populations: the eastern lowland gorilla, in the Kahuzi-Biega National Park (Rep. Dem. of Congo) dropped by 80% between 1994 and 2019. Changing animal, the population of the pink dolphin, a cetacean of the Amazon rivers, in the Sustainable Development Reserve in Brazil, plummeted by 65% between 1994 and 2016.
The decline across continents
Let us consider the world as a whole, and note how the decline is not uniform across the various continents of the globe. The decline in populations in Latin America and the Caribbean was a dramatic 94%, in Africa 66%, in Asia and the Pacific 55%, in North America 20% and in Europe and Central Asia 18%. It should be noted, however, that in Europe and North America a dramatic decline had already taken place before 1970, and is therefore not reflected in the index we are considering.
Living Planet Index for sharks
Let us now consider this large predator. The collapse of oceanic shark and ray populations is 71% (these figures also vary for different shark species). This is according to a study led by Nathan Pacoureau of Simon Fraser University and published in Nature. The reasons can be traced back to an increase in fishing of 18 times the pre-1970 values. 76 species of sharks and rays are critically endangered, 112 are endangered and as many as 167 are beginning to be vulnerable.
Freshwater is the source of life
Freshwater covers about 1% of the earth's surface, but 50% of the world's population lives less than 3 km from its source. In fact, freshwater vertebrates are the group that has suffered the most dramatic decline. Since 1980, 24 of the 31 monitored species are endangered. Fishing, new natural obstacles and pollution are undermining the balance of these waters.
The impact on rivers and migratory fish
Only 37% of rivers longer than 1000 km still remain completely free. For migratory fish this is a considerable problem. Of the 247 species of migratory fish that live partly or wholly in fresh waters, a decrease in their population of 76% has been calculated.
Insects in the crosshairs
Many insect species are threatened by climate change and the destruction of their natural habitat. The reduction in insect populations in areas where agriculture is practiced (subject to climate change) is around 49 percent compared to areas that have not experienced this change, according to a study by the University College in London.
The history of bees
Compared to 1990, a 25 percent reduction in bee species was seen between 2006 and 2015. This was the result of an Argentine study of more than 2,000 pollinator bee species. This does not mean that these species have gone extinct, but that they may become so rare that it is difficult to observe them.
Forests are an indispensable habitat
According to the latest estimates, we have already lost 20% of the Amazon rainforest. Another 6% would already be heavily degraded. For many species of animals, the different land use is the worst threat of all. In fact, as much as 7.6 gigatonnes of Co2 are absorbed by these habitats.
Global warming again
In the event of a further increase of 1.5°C, 6% of insects (out of 31,000 observed species) will lose their natural habitat. In addition, for example, 99% of the world's corals will be destroyed.