Microplastic Levels in Oceans Expected to Exceed 1 Billion Tons by 2026
Recent research indicates that the total amount of microplastics in the environment could increase dramatically, potentially reaching over 1 billion tons by 2060. This alarming scenario holds true even in the face of global efforts to combat waste management issues, according to scientists from France published in the journal Science Advances.
The study, led by researchers from the Géosciences Environnement research facility in Toulouse, modeled the development of global plastic cycles from 1950 to 2100. The findings suggest that by 2045, the annual plastic waste entering the oceans could peak at approximately 23 million tons. The concentration of microplastics is also expected to rise significantly, primarily due to the degradation of larger plastic items over time.
To conduct their analysis, the researchers built upon a 2022 study by the Organisation for Economic Co-operation and Development (OECD), which investigated plastic waste development under various scenarios, from maintaining the status quo to implementing ambitious global measures. The political strategies outlined in all four scenarios include taxing plastic products, enhancing recycling efforts, increasing product durability, expanding landfill capacities, enforcing greater producer responsibility, and providing financial aid to developing nations.
The team differentiated between three categories of plastic sizes for their calculations. Notably, their estimates are significantly higher than those presented in the OECD study. For instance, the OECD's 2019 report estimated that around 1.7 million tons of macroplastics were entering oceans annually, whereas the current study's authors estimate this figure to be as high as 6.1 million tons. When including both large and small microplastics, the total annual plastic influx into oceans is projected to reach 16 million tons.
The researchers attribute the discrepancies in these figures to their reliance on direct measurements and estimates of plastics in the oceans, contrasting with the OECD's use of demographic and economic data to derive their estimates.
According to the current study, the total plastic in the oceans is forecasted to increase from 263 million tons in 2015 to approximately 1.2 billion tons by 2060, even under scenarios that incorporate proactive political measures. In some less ambitious scenarios, these figures could be even higher.
The concentration of small microplastics in the upper layers of the ocean (up to 50 meters deep) is expected to rise from 6.2 nanograms per liter in 2015 to 19 nanograms in a best-case scenario, or even up to 27 nanograms in a worst-case scenario by 2060. Furthermore, the atmospheric concentration of these small microplastics is predicted to increase from 23 nanograms per cubic meter to between 74 and 100 nanograms within the same timeframe.
Even if no additional plastics enter the oceans after 2060 due to improved waste management, the amount of microplastics is anticipated to continue rising. This is due to the existing plastics in the marine environment undergoing further fragmentation at a rate of approximately 3% per year.
The future state of the oceans will largely depend on effective waste management practices, particularly regarding plastic disposal in coastal regions. Estimates indicate that there are around 100,000 landfills situated near coastlines in low-lying areas, many of which are poorly sealed and vulnerable to erosion. The study authors note that this situation contributes to the release of plastics into marine ecosystems. The recovery of these ecosystems will depend significantly on the effectiveness of such landfills in containing plastic and microplastic waste.