Unlike many other firms, however, telecoms operators find their carbon footprints quite easy to work out. That is because their footprints are dominated by one thing: running their networks.

然而，不同于许多其它的行业，电信运营商发现其碳排放的来源很容易确定——它们的碳排放主要来源只有一个：通信网络的运行。