zaterdag 14 februari 2015

Science on marine plastic debris

Science just published an excellent article on the problem of marine plastic debris. Its main conclusion is that
"275 million metric tons (MT) of plastic waste was generated in 192 coastal countries in 2010, with 4.8 to 12.7 million MT entering the ocean."
The authors break this number down by country, and show that four Asian countries (China, Indonesia, Philippines, Vietnam) contribute almost half the plastic waste going into the oceans. The US is 20th in rank, contributing 0.9%; the authors also explain that the EU would be 18th in rank if it were counted as one country, which implies that the EU also contributes about 1% to the total amount of plastic waste going into the oceans. A few more observations:
  • The list is dominated by middle-income countries. The only low-income countries are Bangladesh, Burma, and North Korea. Is this the environmental Kuznets at work?
  • There is a striking correlation between income and the quality of waste management. The countries with the highest percentage of mismanaged waste are low-income countries or lower-middle-income countries. Even upper-middle-income countries have rates between 50% and 80%.
  • Brazil and Turkey are intriguing exceptions: despite being upper-middle-income countries their mismanagement rates are 11% and 18%, respectively. What are these countries doing differently than the rest?
  • The US has a comparatively low mismanagement rate (2%), but compensates its effort by the sheer amount of plastics produced per capita: 2.58 kg, where most other countries range between 0.5 and 1.5 kg. EU figures are not given but I suspect the EU does worse on waste treatment than the US.
  • A notable exception to that observation is Sri Lanka with a whopping 5.1 kg plastic waste produced per capita. What do they need all that plastic for?
Overall I can't help but thinking that the energy invested by well-meaning westerners to reduce their use of plastics is but a drop in the ocean as long as the emerging world does not clean up its act.