Land-Based Plastic Leakage: Understanding The Devastating Impact

Plastic pollution is a pressing issue that affects all ecosystems, including land, freshwater, and marine environments. It is a significant contributor to biodiversity loss, ecosystem degradation, and climate change. While plastic pollution has multiple sources, it is estimated that 70% to 80% of plastic in the oceans comes from land-based sources, primarily transported by rivers. This plastic pollution is the result of a combination of factors, including increasing consumption, improper waste management, and the use of single-use plastic products. Rivers act as the main pathways for plastic to travel from land to sea, and the proximity of rivers to populations and coastlines increases the likelihood of plastic reaching the ocean. To address this issue, a global approach to reducing plastic waste and improving waste management is necessary, along with the implementation of legally binding commitments to tackle land-based sources of marine plastic pollution.

Rivers are the main pathway for plastic to reach the sea

A recent study estimates that more than a quarter of all plastic waste in the ocean could be coming from just 10 rivers, eight of them in Asia. These 10 rivers are the Yangtze, Yellow, Hai, Pearl, Amur, Mekong, Indus and Ganges Delta in Asia, and the Niger and Nile in Africa. The Yangtze alone dumps up to an estimated 1.5 million metric tons of plastic waste into the Yellow Sea.

The probability of plastic waste reaching the ocean via rivers is influenced by various factors, including the proximity of populations to the river, the distance to the ocean, the slope of the terrain, types of land use, and the river basin size. For example, smaller rivers in countries with poor waste management infrastructure, such as the Philippines, Malaysia, and Sri Lanka, are more likely to contribute to ocean plastic pollution.

To tackle plastic pollution, it is crucial to focus on these riverine sources and implement effective waste management practices. This includes improving data gathering and analysis on land and in rivers to better understand and address the problem. It is also important to consider the impact of hydro-meteorological changes, such as floods, on the transport of plastic into rivers and, subsequently, the ocean.

Furthermore, the impact of plastic pollution on estuaries and their ecosystems, such as mangroves, should not be overlooked. Microplastics, mesoplastics, and macroplastics can accumulate in these environments, with higher abundances observed during the high rainfall season.

Mismanaged waste is a key source of plastic leakage

The majority of marine litter is mismanaged plastic waste, with plastic packaging and small non-packaging plastic items (PPSI) being the most common. Tougher laws and regulations have led to improvements in plastic waste management, but these have not been enough to offset the increase in plastic waste generated by countries.

Wealthy, industrialised economies generate the highest amount of plastic waste per capita, with values as high as over 100 kilograms per year and per inhabitant. In populous countries, such as China and India, a lower use of plastic per capita coupled with a high population density can still result in large volumes of plastic waste. In these countries, high rates of plastic waste generation, combined with inappropriate waste management infrastructures, result in significant volumes of plastic waste leaking into the environment.

Currently, the global geography of mismanaged plastic waste generation is disproportionately higher in Asian and African continents. This is due to a combination of factors, including a lack of proper waste management systems and the unfair practice of waste trade between industrialised and developing economies. For example, in 2018, about 80 million metric tons of plastic waste were not managed to international standards, with much of this waste coming from Indonesia, the Philippines, Sri Lanka, and Vietnam. Asian countries, including China, India, Indonesia, Thailand, and Vietnam, account for about 85% of mismanaged plastic waste globally.

To stop plastic pollution, a global approach to reducing plastic waste and managing it appropriately is necessary. This includes investing in modern waste management systems, improving waste management infrastructures, and collection technologies, as well as increasing plastic circularity through new business models that span collection, sortation, and recycling capacity.

Rich countries produce more plastic waste per person

Most of the plastic in our oceans comes from land-based sources, with 70-80% of plastic transported from land to the sea via rivers or coastlines. The remaining 20-30% comes from marine sources such as fishing nets, lines, ropes, and abandoned vessels.

Rich countries produce much more plastic waste per person than poorer countries. Most produce 0.2 to 0.5 kilograms per person per day, compared to 0.01 kilograms in India or 0.07 kilograms in the Philippines. Even when accounting for population size, rich countries generate a lot of plastic waste. For example, the UK generates twice as much plastic waste as the Philippines.

In rich countries, plastic waste is typically managed through incineration, recycling, or well-managed landfills. However, incineration can lead to air pollution and an increase in greenhouse gas emissions. On the other hand, low-to-middle-income countries tend to have poorer waste management infrastructure, resulting in open landfills that can leak waste into the surrounding environment.

The plastic waste trade is another factor to consider. Rich countries, such as the United States, Canada, and the UK, export collected plastic waste to countries in Asia, where it may be recycled or disposed of improperly. This strains the waste management infrastructure in developing countries, leading to plastic waste ending up in dumps, landfills, or incineration, causing further environmental and health issues.

To address the issue of plastic pollution, a global approach is necessary to reduce plastic waste generation and improve waste management practices. While rivers are a significant pathway for plastic to enter the oceans, focusing on a few rivers will not be enough. Effective and legally binding commitments at the global level are rare due to the sensitive nature of territorial sovereignty.

The proximity of populations to rivers increases the risk of plastic reaching the ocean

Rivers are the primary pathways for plastic waste to reach the sea. It is estimated that between 1.15 and 12.7 million tonnes of plastic enter the ocean from rivers annually. The proximity of populations to rivers increases the risk of plastic reaching the ocean due to several factors. Firstly, the probability of plastic entering a river is higher when the river basin has a high population density. This is because populated areas generate more plastic waste, and this waste can easily flow into nearby rivers through paved urban surfaces and drainage systems.

Research has shown that the largest emitting rivers are often located near cities and coastlines. For example, the cities of Jakarta, Indonesia, and Manila, Philippines, are drained by relatively small rivers but contribute significantly to plastic emissions. These cities are also located in tropical regions, where rivers continuously disgorge plastic into the sea due to high precipitation rates. Additionally, the proximity of landfills and dumpsites to river banks increases the risk of plastic leakage into rivers. Landfills located within six miles (10 kilometers) of rivers are particularly likely to spill into them.

The impact of population proximity to rivers is further exacerbated by ineffective waste management practices. Low-to-middle-income countries, which often have higher population densities, tend to have poorer waste management infrastructure. This results in mismanaged plastic waste that can easily enter rivers and eventually the ocean. Improving waste management practices and reducing plastic waste generation are crucial to mitigating the risk of plastic pollution in rivers and oceans.

Furthermore, the distance between the river and the ocean plays a role in the probability of plastic reaching the ocean. Rivers closer to the coast have a higher likelihood of transporting plastic waste into the sea. Additionally, the slope of the terrain, land use patterns, and wind and precipitation patterns can influence the movement of plastic into waterways. All these factors interact with the proximity of populations to rivers, increasing the risk of plastic reaching the ocean.

To address the issue of plastic pollution effectively, a global approach is necessary. This includes improving waste management practices, reducing plastic waste generation, and implementing legally binding commitments to tackle land-based sources of marine pollution. By addressing these issues, we can reduce the risk of plastic leakage from rivers to oceans, even in highly populated areas.

Land-based plastic pollution requires a global approach

The majority of plastic pollution in the oceans originates from land-based sources. Rivers are the primary pathways for transporting plastic from land to the sea. However, the specific mechanisms and factors influencing this process are not yet fully understood. Recent higher-resolution data has revealed that factors such as proximity to populations, distance to the ocean, terrain slope, and land use play a more critical role than previously thought. This suggests that even smaller rivers significantly contribute to plastic emissions.

The impact of land-based plastic pollution is not limited to the environment. It also has economic repercussions, affecting sectors such as small and medium enterprises, tourism, fisheries, agriculture, and water safety. Additionally, plastic pollution poses risks to human health, as toxic chemicals can enter the food chain through marine biota. These far-reaching consequences underscore the urgency of addressing this issue on a global scale.

To effectively tackle land-based plastic pollution, a comprehensive strategy is necessary. This includes improving waste management practices, particularly in middle-income coastal cities, which are hotspots for plastic emissions. It also involves reducing plastic consumption, promoting recycling, and implementing policies that discourage the use of harmful chemicals in plastic production. Furthermore, addressing the legal complexities surrounding bilateral, regional, and multilateral agreements is crucial for establishing binding global standards to combat land-based plastic pollution.

In conclusion, land-based plastic pollution is a pressing global issue that requires a coordinated response. By improving data gathering and analysis, adopting environmentally sound waste management practices, and advocating for international cooperation, we can make significant strides in mitigating the environmental, economic, and health impacts of land-based plastic pollution.

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