Waste Microplastics in the environment could multiply by 2060
The total amount of microplastics in the environment could multiply by 2060. This scenario even applies if the global mismanagement of waste management is actively combated, French researchers reported.
17.04.2025, 05:45
SDA
In the study published in the journal "Science Advances", the group led by Jeroen Sonke from the research institute Géosciences Environnement in Toulouse simulated the development of global plastic cycles between 1950 and 2100.
According to the study, the maximum amount of plastic entering the sea each year could be reached by 2045: a total of 23 million tons. The concentrations of microplastics are also likely to increase significantly - mainly because the larger plastics decompose over time.
Study distinguishes between three size categories of plastics
The starting point for the researchers' calculations was a study on plastics published by the Organization for Economic Cooperation and Development (OECD) in 2022. In it, the OECD team examined the development of plastic waste for various scenarios - from "business as usual" to "ambitious global measures".
"The policy instruments of all four scenarios are based on the taxation of plastic products, increased recycling and durability, the expansion of landfills, greater producer responsibility and financial support for developing countries," write Sonke and colleagues.
For their new calculations, they differentiated between three size categories of plastics:
Macroplastics (larger than 5 millimeters) Large Microplastics (0.3 to 5 millimeters) and Small Microplastics (smaller than 0.3 millimeters).
Calculations based on measurements and estimates
Some of the values determined by Sonke's team are considerably higher than in the OECD study. For example, the OECD study estimates that 1.7 million tons of macroplastics entered the sea each year in 2019. Sonke and colleagues even come up with 6.1 million tons. Including large and small microplastics, the figure is as high as 16 million tons of plastic currently entering the sea every year.
The researchers explain the difference to the OECD data by the fact that they are based on measurements and estimates of the quantities of plastic in the oceans. The OECD, on the other hand, derived its values from population density, gross domestic product per capita and country-specific statistics on municipal waste generation.
According to the current study, the total amount of plastics in the oceans will increase from 263 million tons in 2015 to 1,200 million tons in 2060. According to the study, this amount applies to the scenario with ambitious political countermeasures. The values for the other scenarios are even higher.
Plastic present in the oceans is gradually decomposing
The amount of small microplastics in the uppermost water layer of the oceans - down to a depth of 50 meters - will therefore increase from 6.2 nanograms - i.e. millionths of a milligram - to 19 nanograms per liter in the best-case scenario from 2015 to 2060, and even to 27 nanograms in the worst-case scenario. In the atmosphere, the proportion of these small microplastics per cubic meter of air will increase from 23 nanograms to between 74 and 100 nanograms over this period.
Even if no more plastic enters the sea from 2060 as a result of waste mismanagement, the amount of microplastics will still continue to increase, the research group emphasizes. This is because the plastic present in the oceans will continue to break down - at a rate of around three percent per year.
According to the team, how the situation in the oceans will develop depends not least on the storage of plastic waste - particularly in coastal regions. "It is estimated that there are 100,000 landfills near the coast in low-lying areas worldwide, which are often not sealed and are exposed to the risk of erosion," write the authors of the study. As a result, plastics end up in the marine environment. The recovery of ecosystems also depends on the efficiency of such landfills in retaining plastic and microplastic waste.
