In October, the United Nations Environment Programme (UNEP) released the latest assessment report from pollution to solution: a global assessment of marine litter and plastic pollution. The report shows that there are still about 75 million to 199 million tons of plastic waste in the ocean, accounting for 85% of the total weight of marine waste. Without effective intervention, it is estimated that by 2040, the amount of plastic waste entering the aquatic ecosystem will nearly triple to 23-37 million tons per year.
For a long time, plastic waste has been polluting the environment on which we live, including the ocean. This situation is largely caused by unsustainable production and consumption patterns and imperfect waste disposal methods.
Influenced by COVID-19, a large amount of plastic waste produced by protective equipment and its additional packaging has been discarded directly into the environment, which aggravates the pollution situation. If the life cycle analysis of plastics is carried out, the global greenhouse gas released by plastics in 2015 is 1.7 billion tons of carbon dioxide equivalent. This figure is expected to increase to about 6.5 billion tons of carbon dioxide equivalent by 2050, accounting for 15% of the global carbon budget.
In order to draw people's attention to marine plastic pollution, the United Nations Environment Programme (UNEP) issued the assessment report. According to reports, the purpose of this assessment is to let decision makers and the general public know that marine garbage (especially plastic and micro plastic garbage) can have far-reaching effects and serious consequences. The United Nations calls on the world to take cooperative intervention measures to prevent the further intensification of marine plastic pollution, endangering human security and ecological balance.
Marine garbage and pollutants mainly come from land. The report shows that about 9.2 billion tons of plastic products were produced worldwide from 1950 to 2017, of which about 7 billion tons became plastic waste. The recycling rate of these plastic wastes is very low, less than 10%. Millions of tons of plastic waste are discarded into the natural environment, or transported thousands of kilometers away for incineration or dumping.
The report warns that self proclaimed "biodegradable" plastics are also a big problem. They may take years to degrade in the ocean. Moreover, these "biodegradable" plastics may not cause less harm to individuals, biodiversity and ecosystem functions than ordinary plastic waste.
In addition, the decomposition of plastic products, leachate from landfills, sludge from wastewater treatment systems, particulate matter in the air (such as wear and tear caused by tires and other items containing plastic), agricultural runoff, hull damage and accidental falling of goods into the sea may all make micro plastics enter the sea. Extreme weather events such as floods, storms and tsunamis may also involve a large amount of plastic waste in coastal areas and river inlets into the sea.
The report points out that garbage and waste plastics in the sea will have a significant negative impact on the natural environment and all aspects of human society:
From the biological level, garbage and plastics in the ocean will pose a serious threat to all marine life. Plastic is the largest, most harmful and longest living type of marine garbage, accounting for at least 85% of the total amount of marine garbage. Plastic waste can cause fatal injuries to whales, seals, turtles, birds and fish, as well as invertebrates such as bivalves, plankton, worms and corals, including suffocation by winding the body, tearing internal tissues, depriving it of oxygen and light, leading to physiological stress and poisoning.
At the ecological level, the impact of plastics on plankton and marine, freshwater and terrestrial systems will also indirectly change the global carbon cycle. Marine ecosystems, especially mangroves, seagrasses, corals and salt marshes, play an important role in carbon storage. The greater the harm caused by human beings to the ocean and coastal areas, the more difficult it is for marine ecosystems to absorb carbon emissions and resist climate change. When plastics decompose in the marine environment, the micro plastics, micro fibers, toxic chemicals, metals and organic micro pollutants will be transferred to the water and sediments, and finally enter the marine food chain. These substances will affect the reproductive success rate and viability of marine organisms, and damage the ability of "ecological engineers" corals and worms in aquatic ecosystems to build coral reefs and change sediments through biological disturbance.
From the perspective of human health, marine garbage and plastic waste will also threaten mankind itself. Plastic garbage burned in the open air, seafood polluted by plastic, pathogenic bacteria on the plastic surface, and toxic and carcinogenic substances precipitated from coastal waters will have a serious impact on human health. Microplastics can enter the human body through respiration and skin absorption and accumulate in human organs. Humans may also absorb a large amount of microplastics through seafood, which may pose a serious threat to coastal and indigenous communities whose main food source is seafood. In addition, plastic waste in the ocean also has a certain impact on human mental health. People may lose the desire to play on the beach, and their psychology may be hurt by the cognition that marine animals are in danger.
At the economic level, marine garbage and plastic pollutants pose a serious threat to the income sources of coastal communities and shipping and port operations. It is estimated that the annual economic losses and clean-up costs caused by marine plastic pollution to tourism, fisheries and aquaculture are at least US $6-19 billion, and the annual loss of marine natural capital is as high as US $500-250 billion if converted into monetary value. If the government requires enterprises to pay waste management fees according to the expected amount of waste generated and recycling capacity, it is expected that plastic waste in the ocean may cause financial losses of US $100 billion a year by 2040.
At present, the national and regional organizations have taken a series of measures to deal with the problems of marine waste, especially the marine waste.
There are many international conventions and organizations around the world committed to addressing marine litter and pollution, including the Basel Convention, Rotterdam Convention and Stockholm Convention, the international maritime organization, the 1972 London Convention and its conference of the parties, and the FAO Committee on fisheries. WTO member states are also taking actions to support the international community to reduce and eliminate plastic products, promote ministerial dialogue and adjust trade policies, so as to reduce plastic pollution.
In addition, a series of legislative means, soft legal measures and management regulations are also showing results. The ban on plastic products, consumption tax on plastic products, improvement of waste treatment technology, economic incentives, extended producer responsibility system, regional conventions, marine waste removal plans, educational initiatives and public awareness campaigns are being implemented on a large scale. The change of public attitude and the improvement of public attention, awareness and action level on recycling or plastic substitutes also provide impetus for the implementation of this series of plans.
The plastics industry is advocating the use of innovative technologies beneficial to the environment, such as using blockchain technology to improve the marking and tracking links in the supply chain of plastic products. Many enterprises have initiated joint industry initiatives, focusing on the recycling of plastics, the development of bioplastics and alternative materials, and the application of ecological design. At the same time, some multinational companies have also made plans to restructure their supply chains to align them with national policies and shift the focus of production from fossil fuel based plastics to recycled materials.
The experts who participated in the assessment report also put forward some important research areas that need urgent attention, including quantitative analysis of plastic debris from several major sources and its movement and decomposition in different marine ecological environments; Quantitatively analyze the damage and economic loss caused by marine garbage to marine industry, ecosystem and human health; Improve plastic recycling technology and standards; Further develop the recycling and ecological design of plastic products; Improve the risk assessment framework; Deeply understand the impact of marine garbage and plastic waste on social norms, people's attitudes and behaviors.
Although relevant persons and departments have put forward corresponding solutions, the deployment of these solutions is uneven and scattered. Therefore, it is particularly important to combine the actions of government, enterprises and citizens at all levels. A single solution cannot really reduce the amount of plastic waste entering the ocean. We need to take coordinated and systematic intervention measures in the upstream and downstream links of plastic production and use in order to truly curb the further intensification of marine pollution.