In a recent study on trade and the environment, the Yale Center for Environmental Law & Policy conducted a pilot time trend analysis, painting a clearer picture of the complex relationship between country-level CO₂emissions and trade intensity. The analysis examines changes in trade intensity (as seen through trade as a percent of GDP) alongside two measures of CO₂ emissions—CO₂ per capita and CO₂ per GDP. The former CO₂ measure indicates emissions intensity per person, while the latter indicates the emissions intensity of the economy.

Time trends show that the most common phenomenon is a decline in emissions per GDP with increasing trade intensity, an indication that economies become more carbon efficient as trade becomes a greater portion of GDP. However, the data also reveal a troubling trend among countries: emissions per capita most commonly increase with increasing trade, an indication that trade might be harmful in terms of emissions. MORE