字幕列表 影片播放 列印英文字幕 Plastic is incredible. It helps send fresh food around the world, keeps us warm (or cool), and dry, and enables medicines like vaccines to be delivered safely at scale to billions of people. But it's also increasingly in our soil, our oceans and the stomachs of birds, mammals and fish. In fact, the amount of plastic on our planet now outweighs all the land and sea creatures currently alive. So, how can we sort out our problem with plastic? These are sights we're all too familiar with - plastic floating in the oceans or piled up in bursting landfills. And whilst our instinct might be to demonise the material itself, arguably the main problem is how we use it. But first, it's worth remembering what a versatile and useful material plastic is, making everything from car parts to bulletproof vests and wind turbines. It was first created in the 1860s, with a noble intention to replace elephant ivory used in billiard balls. Plastic became popular with the military during the Second World War, but it only grew at scale commercially in the 1960s. Since then, it's been produced in many different forms, including polystyrene, acrylic, nylon, polyester and vinyl, and has been incorporated into almost every aspect of our lives. Plastic is so cheap and easy to make, our use of it has grown at a phenomenal rate, and this has unintended consequences. It's been found in the guts of creatures living deep in the ocean and even in human placentas. And because most plastic is based on oil, its use contributes to climate change, accounting for around 3.5% of the world's greenhouse gas emissions. Some plastic can be recycled, but globally only about 9% is. While decent recycling exists in some countries, in others there's just no real recycling infrastructure. And when most plastic is recycled, its quality deteriorates. And no matter how many ocean or river clean-ups we arrange, our environment simply cannot cope with our love of single-use plastic. In the UK alone, we throw away over 2.5 billion disposable coffee cups a year. Conventional plastic can take anywhere from 20 to 500 years to decompose, with the average supermarket bag needing around 20 years and a plastic bottle around 450 years. Biodegradable plastic - made from plants rather than petrochemicals or fossil fuels - isn't the simple answer either. Bacteria degrades bioplastic much more rapidly than conventional plastic, but that releases both methane and carbon dioxide - greenhouse gases that contribute to global warming. It also breaks down into microplastics, meaning it gets into our food systems via the soil and fish. One way to address these problems is to take a circular approach to plastic, designing it to stay in use for as long as possible. In the current model, we take raw materials, make them into plastic products, likely only use them once and then throw them away. In the circular model, plastic would never become waste or pollution. We could eliminate its unnecessary use, such as excessive food packaging, and ensure that all plastic products can be upcycled. A coffee cup can be turned into a coat. A toothbrush could help make a suitcase. Improving the quality and design of plastic so that we pull its polymers - the long chains of molecules that make it up - apart and put them back together in an endless loop would mean that plastic would be made once and then reused multiple times. It could then be cleaned, processed and remoulded to make different types of plastic or a new product of the same quality. This approach, which would help reduce both pollution and greenhouse gas emissions, requires commitment and innovation. But it is achievable. A temple in Thailand turns plastic bottles into new robes for monks, helping to process ten tonnes of plastic waste every month. Returnable packaging schemes, where consumers return reusable packaging in a shop or a drop-off point, help to eliminate waste from deliveries. A fleece jacket typically contains 95% recycled polyester fibre. Let's face it, we're not going to completely get rid of plastic from our lives, nor would we want to. But with the equivalent of 2,000 rubbish trucks full of plastic dumped into the world's oceans and rivers every single day, we also can't leave future generations to clean up our mess. Our attitude to plastics has to change. We need to make better plastic, treat plastic items as indispensable and stop thinking that it can be used once and then thrown away - because, let's be honest, the "away" in this scenario doesn't really exist.
B1 中級 美國腔 How to solve the world's plastic problem | BBC Ideas 97 0 林宜悉 發佈於 2024 年 04 月 28 日 更多分享 分享 收藏 回報 影片單字