When carbon footprints hop

摘要

Despite having achieved legally binding commitments on emissions reductions, many countries have increased their appetite for carbon-intensive products, making up the difference through international trade. Anna Petherick reports on the sticky task ofregulating these invisible carbon flows.By convention, as well as through pragmatism, emissions of greenhouse gases have always been attributed to the location where the combustion reactions that produced them happened. International climate change negotiations abide by this convention and policymakers are accustomed to thinking of emissions in this way. Such an accounting system accommodates the idea that carbon physically travels across international borders. Indeed, it does with great frequency: 37% of the planet's emissions come from fossil fuels that are burnt in a country other than the one in which they were sourced.