2018/09/16: How bad is the situation with plastic pollution? Rather bad, by all means. Citing from a recent paper by Geyer et al., more than 8 billion tons of plastic have been produced since the 1950s. Of this mass, 9% percent was recycled, 12% was incinerated, the rest is still around. It is this mass of plastics, billions of tons, which generates the pollution we see today. It is almost one ton of plastic waste for every human being living today. Imagine if it were magically to appear in your living room: one ton for every member of your family.
Still following Geyer et al., we learn that in 2015 the world produced 380 million tons of plastics from fossil hydrocarbons. To get some idea of how polluting this mass is, we can compare it to the total carbon emissions produced by hydrocarbon combustion, which today can be estimated to be around 9 billion tons per year. As an order of magnitude comparison, we can say that about 4% of the fossil hydrocarbons we extract become plastics.
4% doesn't seem to be a large amount, but it is not negligible, either. Apart from the horrible state of some beaches, the islands of plastics in the oceans, it is a lot of carbon pumped into the ecosystems and its effects are scarcely known, especially on humans: we are all eating microplastic particles, today. What will that do to our health, nobody knows -- we are all guinea pigs in a great experiment. The long-run problem is that all this plastic is made from fossil hydrocarbons, it is going to be gradually oxidized and turned into gaseous CO2. Then, it will contribute to global warming.
is bioplastic the solution to the problem? As it often happens, quantification makes short work of ideas that seemed to be good in theory. Today, bioplastics are made mainly from cereals (corn) or directly from sugar. According to the data from Statista, the world's production of sugar was about 170 million tons in 2017, less than half the amount needed to make the currently produced amounts of plastics even in the wildly optimistic assumption of a 100% efficient process. About grain, the data tell us that in crop year 2016/2017, a total of approximately 2.62 billion metric tons of grain were produced worldwide. Again in the wildly optimistic assumption of a 100% efficient production process, it means we should set aside about 15% of the world's grain production - more realistically about 20%-25%. Then, of course, efficiency can be improved and we may find ways to make plastic out of plants not used as food. But, at present, it is the way things stand.
There is just so much that agriculture can do: it can't feed more than 7 billion people and, at the same time, provide fiber, chemicals, and fuel for everybody.
it would be perfectly possible to develop and implement international agreements that would curb the use of plastics made from fossil fuels and eventually ban it completely. That implies changing something in our everyday life: the "overpackaged" products that today are so common in supermarket aisles would have to disappear. But packaging is not evil: it is a way to store food more efficiently. We need to learn how to be much more efficient with it.