Based on a study released today, Canada has one of the best records in the world for protecting the environment and human health. Canada performs well on a comprehensive index of environmental performance, ranking 10th out of 33 high-income OECD countries with a score of 68.5—well above the OECD average (62.9). Despite Canada’s overall strong performance, it’s important to critically analyze areas where Canada isn’t performing as well.

Based on the methodology used in the study, countries are spread-out in the relative rankings, even when there was little absolute difference between the scores of countries that place five or 10 steps apart in the rankings.

For example, Canada ranks 29th out of 33 countries based on its sulphur (SOx) emissions intensity, which measures SOx emissions generated per unit of activity, but received a relatively high score of 84.5. This means that most examined countries do very well on this measure and there’s little difference between Canada and the top performers.

Moreover, consider this. In terms of reducing sulphur emission intensity, which assesses each country’s progress on lowering emissions per unit of economic activity over a decade, Canada ranks 17th with a score of 82. But 7th place Italy is not much higher, with a score of 92. In other words, if Canada ranks in the middle of the pack, it’s still performing well due to the tight rankings.

There are some areas where Canada’s ranking is even lower, which can be misunderstood. For example, on measures related to greenhouse gases, Canada ranks 31st out of 33 on carbon intensity, which measures CO2 emissions relative to the size of the economy. However, given Canada’s cold climate, large natural resource sector and long transportation distances, this result should not be surprising. Most of the other OECD countries have milder climates and higher population densities, which results in lower daily energy needs.

Clearly, the size of a country’s land mass drives some of its need for energy and subsequent greenhouse gas emissions. But what if other countries had to contend with typical Canadian distances? If one adjusts for land mass, Canada’s ranking would rise from 31st to 2nd place on the carbon intensity measure.

Overall, as shown in the study, Canadians enjoy high levels of environmental quality relative to other high-income countries. And in areas where Canada’s ranking is low, it’s sometimes unavoidable due to our geography and/or cold climate. While in other cases it reflects the tight rankings—where countries are often separated by mere fractions. Readers should carefully consider indicator rankings, scores and external factors when analyzing Canada’s environmental performance.