Paul Leadley, who works at Paris-Sud University on the consequences of climate change for plants, is one of the lead authors of the report. Read on for his preview of the main points.
What is the mission of the IPBES?
Paul Leadley: The IPBES is the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services—that is, services provided to humans by ecosystems. It helps governments make decisions by providing them with independent expertise on biodiversity on a global scale, like the IPCC [Intergovernmental Panel on Climate Change] does for the climate.
It was created in 2012 to compensate for the lack of interaction between scientists and political decision makers on the issue of biodiversity, and it now has more than 130 member states.
The IPBES is currently finalizing an important report evaluating global biodiversity. What is it about?
We have already evaluated biodiversity continent by continent and prepared reports on soil degradation and restoration and on pollinators. This report is a global inventory of biodiversity. It discusses changes to biodiversity, and the services it provides us, from the mid 20th century to today, with forecasts extending to 2050. We have also attempted to understand the causes of the observed declines and to deliver a panel of solutions.
The study is based on the work of more than 150 international specialists over three years. The aim was to produce an assessment that would be easily accessible to decision makers. This is of particular importance, since it will serve as the basis for the decisions to be made at the Conference of the Parties to the Convention on Biological Diversity, to be held in China in 2020.
What overall observation does the report make?
Studies have been saying it for years, and our evaluation confirms it: there has been a sharp decrease in the size of the populations studied. To put it another way, many species are experiencing a rapid decline.
In its latest Living Planet report, the WWF spoke of an overall decrease of 60% in the size of monitored populations. In 2018, a study by CNRS and the Muséum National d’Histoire Naturelle reported that one third of birds have disappeared from French countrysides in the span of 15 years. Another study revealed that insect biomass has decreased on the order of 80% in Germany over 30 years.
Agriculture is one of the primary causes of this loss of biodiversity, via the habitat destruction it causes. We still have a major problem with deforestation in South America—although it has slowed substantially in recent years—and in countries such as Indonesia, where palm oil production is eating away at the tropical forests. There is a great deal of concern regarding Madagascar, where many endemic species [that cannot be found anywhere else] are impacted by pollution and changing land uses.
There is a heated debate over the prohibition of glyphosate... to what extent do pesticides affect biodiversity?
The role pesticides play in the loss of biodiversity is quite controversial. Neonicotinoids, a new class of pesticides toxic to insects, have been implicated in the relatively large decline of pollinators in Europe and North America.
But what the IPBES notes in its evaluation is that there are multiple causes. The decline of bees is due to the arrival of diseases from other regions, the introduction of invasive species, pesticides, and the lack of flowers to gather pollen from. On that note, agriculture and other human activities have a very strong impact on the availability of flowers.
At this point, it is very difficult to state with certainty that pesticides are the primary cause of the collapse of certain populations.
Has climate change already had an impact?
Yes, it can be seen above all in changes to the geographical ranges of biodiversity. Many species are in the process of migrating, expanding, or losing their territory. The pine processionary caterpillar is one example: 30 years ago, the northern limit of its territory was in the Loire, but it can now be found in the greater Paris region, because milder winters allow the larvae to survive further and further north.
The main concern is loss of territory that has become too hot for certain species. My unit, for example, is studying multiple species of rare plants in the La Brenne regional natural park in the Indre department. We have observed that climate change may quickly erase them from the region.
What about the services we receive from ecosystems? How much have they been affected?
It is important to distinguish between different types of services: those related to supplies (of food, wood, etc.) from ecosystem functions (carbon storage, water treatment, etc.) and everything related to culture (beauty, wellness, etc.).
Still, we observe that in many places, resources are being removed in greater quantities to the detriment of carbon storage, water quality, or wellness services.
What will the experts and governments discuss in Paris starting on April 29?
The bulk of our work will be to produce a summary for decision makers. This summary, which includes the most important messages, results, and options, will be presented to the public at UNESCO headquarters in Paris on Monday, May 6.
The document is negotiated between scientists and government representatives. The mechanism is the same one used by the IPCC: countries may comment on the document and then, if the scientists do not object, certain passages may be modified. We hope that the document will be adopted by governments, because they will need to use it as a foundation for their decisions.
Is it difficult to get so many governments to agree on a single text?
The content of this evaluation is not particularly controversial. The overall observation is relatively known and generally shared by the scientists and governments. The real challenge is the need to raise levels of awareness about the biodiversity crisis we are facing. It is essential for it to be recognized as a key issue, alongside the climate.
How do you explain the fact that preserving biodiversity is struggling to emerge as a crucial issue?
One reason could be the lack of scientific studies on the topic, as well as the absence, until 2012, of a structure like the IPBES. While the information is not new, a clear link between science and policy was lacking. The IPCC has existed for much longer than the IPBES.
It may also be because biodiversity is more difficult to grasp, because there are no simple measurements. With the climate, we can talk about increasing temperatures, rising ocean levels... But what do we talk about for biodiversity? Species extinction? Declining populations? Changing ranges? The issue cannot be summed up in a single indicator. And that complicates the task of communicating with decision makers and the public about the issue.
The IPBES’s work will also serve as a foundation for the discussions in Kunming, China in 2020, at what has already been hailed as the equivalent to the COP21 for biodiversity.
It is clearly the next big step for biodiversity! We hope that ambitious objectives for preservation will be brought up and widely recognized. The goal is to arrive at an equivalent of the Paris Agreement, but for biodiversity.