Another eco-crisis – and nobody takes notice
German car drivers have long noticed: the number of insects is decreasing. Compared to 20 years ago, the windshield is hardly smeared with the annoying creatures after racing on the autobahn. What may be pleasant for German car pilots has the potential to develop into a global ecological catastrophe. To some, this may sound alarmist, and that is exactly what it is supposed to sound like: one can easily assume that with a massive reduction or even the extinction of insects, life on this planet as we know it would no longer be possible. Our food, fresh water, hygiene and cleanliness are all threatened by the disappearance of insects. Because they are something like the multi-taskers of our ecosystem. They are used by crops and wild plants for pollination (according to the World Council for Biological Diversity (IPBES), five to eight percent of current food crop production depends directly on insect pollination. This corresponds to an annual market value of many hundreds of billions of euros), the degradation of garbage and our excrement takes place largely through insects, insects serve as food many animals, especially amphibians, birds and fish, i.e. without insects no frogs, larks, or trout. And without insects there is also no decomposition of cow dung or wild animals’ manure. Imagine that there is excrement everywhere. When cows were imported into Australia, this scenario became reality. Because the beetles that process it did not exist there. The native beetles were only specialized in kangaroo manure. The problem could only be solved by importing dung beetles from South Africa.
Experts in Germany already sounded the alarm 18 months ago. A study with data from countless volunteer insect counters came to the conclusion that the number of insects in Germany was falling dramatically. Has anyone noticed? Did the press report on it widely? Was Germany perhaps just an isolated case? The last question has now been answered by a scientific overview study under the leadership of the Australian ecologist Francisco Sánchez-Bayo of the Sydney Institute of Agriculture (Francisco Sánchez-Bayo, Kris, A. G. Wyckhuys, Worldwide decline of the entomofauna: A review of its drivers, Biological Conservation, Volume 232, April 2019, p.8). This is the first comprehensive scientific analysis of the decline in insect populations worldwide. The authors present an overview of 73 historical reports on the decline of insects, mainly from North America and Europe, and systematically evaluate its underlying drivers. Their report reads like a horror story. It shows the dramatic declines that could lead to the extinction of 40% of the world’s insect species in the coming decades. These include butterflies (over 50% decline), beetles (almost 50% decline) and hymenoptera, which include ants, wasps and bees (down 45%), as well as numerous aquatic insects. Nearly half of all species experience sinking numbers. Global insect mass shrinks by a total of 2.5 percent per year. If this development continues, most insects could have disappeared within a century, according to the authors. „If insect species losses cannot be halted, this will have catastrophic consequences for both the planet’s ecosystems and for the survival of mankind”, says Sánchez-Bayo.
The main causes of species decline are, (in order of importance): i) habitat loss through the conversion to monoculture agriculture (a single crop field is as valuable to most insects as a tarred parking lot), and through urbanization, such as the construction of roads and houses; ii) pollution and poisoning of insect habitats, mainly by synthetic pesticides and fertilizers (the authors believe new classes of insecticides introduced in the last 20 years, including neonicotinoids and fipronil, have been particularly damaging as they are used routinely and persist in the environment); iii) biological factors such as introduced alien species that threaten the diversity of native insects; and iv) climate change. The latter factor is particularly important in tropical regions, but affects only a minority of species within temperate zones in colder and mountainous areas.
Only rarely do scientists become so concrete in their statements and use such strong language as in this review. Neither do they combine their work with a call for tangible measures. “We wanted to really wake people up” and the reviewers and editor agreed, Sánchez-Bayo said. The report explicitly recommends a rethink of current agricultural practices in order to slow down or even halt current dramatic trends and preserve the ecological functions of insects that are so important. In particular, the authors mention the overcoming of monocultures and a significant reduction in the use of pesticides. In order to halt insect mortality, agriculture would therefore have to undergo a large-scale conversion. We need to create more structurally rich habitats, such as meadows, bush landscapes, etc. instead of just wheat fields and apple plantations. Fields would have to be made more insect-friendly, for example with flower strips and hedges at their edges. A more sparing use of pesticides and fertilizers must protect the insects‘ habitat.
Even experts were shocked by the extent to which insects have died. It is important to note that studies on insect numbers often involve a great deal of uncertainty. The insect population can vary greatly from year to year, depending on the weather (for example, cold winters with lots of snow can decimate the population). Important are therefore studies over long periods of time, albeit being very time-consuming and laborious. It is equally important to aggregate these many local studies in order to show a global trend. The Bayo study did the latter for the first time.
And as is so often the case, both the journalists‘ as well as the politicians‘ guilds have reacted very hesitantly. The report was hardly mentioned in the daily press, if only on the back pages (exceptions being the Guardianand theHuffington Post). As always, our news hardly mentions significant scientific developments, while the annual useless rendezvous of a self-declared world elite in Davos or a groundless two-page pamphlet by opponents of pollutant limits (as in Germany recently) are described in great detail. Politicians like the German Federal Minister of Agriculture, Julia Klöckner, only play down the issue by demanding further insights before concrete political initiatives can be started. It is always the same pattern: with the demand for more knowledge, necessary steps are delayed until it is too late. The former wine queen can hardly be expected to read such scientific studies herself. Where are those who inform her about the actual state of research?
But that we citizens can take things into our own hands in order to take decisive action against frightening developments, when politicians and governments are too slow, blind or controlled by powerful lobby groups, is shown by the example of the popular initiative for the protection of bees in Bavaria of January 2019. People queued up to sign this initiative, just as if Madonnawas giving out free tickets for her next concert. The initiators from the ecological-democratic party (ÖDP) have thereby put the CSU led Bavarian federal state government under some substantial under pressure. With this study they have now won a further strong scientific argumentation basis.