What is
biodiversity?

Biodiversity means biological diversity in a multi-layered sense: it refers to the diversity of all habitats (such as coniferous forests, tropical rainforests, moors, rivers, etc.), the diversity of species (whether animal, plant, fungus or unicellular organism) and genetic diversity.

Life can be found even in the most inhospitable corners of the eleven major habitats on Earth (box below). After all, life has had billions of years to become creative.

Thanks to specialization, symbioses and other evolutionary tricks, there are now over 8 million species. Of which around 1.7 million have been documented and described.

If we delve one level deeper into diversity - into genetic diversity - our imagination is challenged even more.

This is about the genetic material of every single individual on this planet. If you multiply the human genome alone, with around 23,000 genes, by the world's population, you have an initial idea of how gigantic the genetic diversity of the Earth is as a whole.

What about biodiversity?

It is part of evolution that new species constantly emerge and other species die out. However, the so-called "extinction rate" is currently many times higher than ever before in human history. Scientists have come to the conclusion that we are at the beginning of a mass extinction. It would be the sixth mass extinction in Earth's history. So far, the Earth has experienced 5 mass extinctions, in which over 75 percent of species died out, for example due to volcanic eruptions or, as in the case of the last mass extinction 66 million years ago, due to meteorite impacts. Humans alone would be responsible for the sixth mass extinction.

The widely acclaimed report by the World Biodiversity Council (IPBES 2019) provides an insight into the state of biodiversity worldwide. The report came to the sad conclusion that 1 million plant and animal species are threatened with extinction. Many could disappear in the next few decades.

Since 1900, there have already been a fifth fewer land animals. 40 percent of amphibian species (frogs, salamanders...), a third of reef-building corals, and more than a third of all marine mammals (whales, seals...) are threatened with extinction.

But diversity is also at risk in agriculture. Since 2016, 9 percent of old livestock breeds have become extinct and 1,000 more are under threat. Globally, the diversity of cultivated plants is decreasing and many of their wild relatives are not sufficiently protected from extinction (IPBES 2019).

This may not sound so bad, as they are breeds and varieties bred by humans. But species-poor systems are less resilient. Old, robust breeds and varieties, on the other hand, often react less sensitively to the increasingly frequent climate changes and extreme events.

What are the biggest threats to biodiversity?

The World Biodiversity Council report cites the following as the main reasons for the threat to biodiversity:

1. Change in land use and marine use

More than a third of the country's surface area and three quarters of its freshwater resources are used for agriculture. Urban areas have more than doubled in size since 1992. Around 50 percent of all natural ecosystems worldwide have disappeared.

2. overexploitation of resources

Every year, 60 billion tons of renewable and non-renewable resources are consumed worldwide. That is almost twice as much as in 1980.

3. climate change

Greenhouse gas emissions have doubled since 1980. Rising temperatures and other negative effects of climate change go hand in hand with the extinction of species.

4. soiling

Plastic pollution has increased tenfold since 1980. 300-400 million tons of heavy metals, solvents, toxic sludge and other industrial waste are released into water bodies every year. Fertilizers washed into coastal ecosystems have resulted in 400 "dead marine areas". Pesticides, such as neonicotinoids, contribute significantly to species extinction.

5. introduced species

Introduced species spread explosively and often displace native species. In countries where the development of these species has been documented, they have increased by 70% since 1970.