Canada's Impact on the Global-Scale and Urban-Scale Carbon Cycle

碳循环描述了二氧化碳（一种温室气体）在大气、海洋和陆地之间的流动，是地球维持生命的关键机制之一。众所周知，向大气层排放二氧化碳和其他温室气体会使全球气温升高，并对地球的地球化学产生不利影响。全球约70%的温室气体排放来自城市地区，排放到大气中的温室气体约有一半留在那里：其余的被陆地和海洋吸收。对碳循环相关气体进行长期、频繁、高质量的大气测量是进一步科学理解碳循环的关键。

The carbon cycle describes the flow of carbon dioxide, a greenhouse gas, between the atmosphere, oceans and land, and is one of the key mechanisms by which the Earth sustains life. It is well understood that the emission of carbon dioxide and other greenhouse gases into the atmosphere raises global temperatures and adversely impacts the biogeochemistry of the planet. About 70% of the global greenhouse gas emissions originate from urban regions, and about half of what is emitted into the atmosphere remains there: the rest is removed by the land and the oceans. Long-term, frequent, high-quality atmospheric measurements of carbon cycle-relevant gases are the key to further our scientific understanding the carbon cycle.