(Micro)plastic crisis: Un-ignorable contribution to global greenhouse gas emissions and climate change

Abstract

The rapid development of plastic industrials has created a variety of plastic products, causing revolutionary progress in chemistry, physics, biology, and medicine. Large-scale production and applications of plastics increase their possibility of entering the environment. Previous environmental impact studies typically focused on the toxicity, behavior and fate; limited attention was paid on greenhouse gas emissions and climate change. With the increase of plastic waste, the threat of plastic pollution to the earth’s climate has been gradually taken seriously. Evidence showed that greenhouse gas emissions occur at every stage of the plastic life cycle, including extraction and transportation of plastic raw materials, plastic manufacturing, waste treatment and entering the environment. The oil and gas industries used to make plastics are the main sources of greenhouse gas emissions (from the extraction of raw materials to the manufacture of plastics). Emissions of greenhouse gases during manufacture are mainly controlled by the production facilities themselves, usually depending on the efficiency, configuration and service life of equipment. Additionally, there are some unintended impacts, including transport requirements, pipeline leakage, land use, as well as impeding forests as natural carbons sinks. Recycling of plastic waste energy seems to be a good way to deal with waste plastics, but this process will release a lot of greenhouse gases. With this energy conversion occurring, the incineration of plastic packing waste will become one of the main sources of greenhouse gas emissions. Furthermore, plastics released into the environment also slowly release greenhouse gases, and the presence of (micro)plastics in the ocean will seriously interfere with the carbon fixation capacity of the ocean. In its current form, greenhouse gas emissions from cradle to grave of plastics will reach 1.34 gigatons per year by 2030 and 2.8 gigatons per year by 2050. This will seriously consume the global remaining carbon budgets, thereby threatening the ability of the global community to keep global temperatures rising by below 1.5 °C even 2 °C by 2100. In order to achieve this goal, the total global greenhouse gas emissions must be kept within the remaining carbon budget of 420–570 gigatons. The accumulative greenhouse gas emissions from cradle to grave of plastics may exceed 56 gigatons by 2050 (approximately accounting for 10%–13% of the total remaining carbon budget). As the plastic industry plans to expand production on a large scale, the problem will worsen further. The World Economic Forum forecasted that by 2030, the production and use of plastics will grow at an annual rate of 3.8%, and this growth rate will fall to 3.5% per year from 2030 to 2050. However, there are significant challenges and uncertainties in this estimation, and challenge and uncertainty factors come from all aspects. Recently, several organizations and researchers have started to discern the relationship between greenhouse gas emissions and plastic industrials, but relevant research on these impacts is still in its infancy. Consequently, the contribution of plastic pollution to greenhouse gas emissions and climate change should be given immediate attention and it needs to further explore the impact of plastic pollution on greenhouse gas emission and climate change. The implementation of measures to solve or alleviate the (micro)plastic crisis was critical necessary and proposed: (1) production control of global plastics; (2) improving the treatment and disposal of plastic waste; and (3) assessment of the impact of global environmental (micro)plastics on climate.