Driving and flying are known climate sins. Previously unknown: the dark secret of e-mail. BRISANT explains why it can also be bad for the environment under certain circumstances. In 2022, approximately 666 million tons of carbon dioxide (CO2) were emitted in Germany. Road and other transport represents 147 million tons of this. Frequent flying and long driving times are harmful to the climate. Few people dispute this fact. However, the focus on the digital space is much less common in the climate debate. Yes, even the Internet can generate a huge amount of CO2, for example when streaming. And good old email could also turn out to be a climate sin.