Today I woke up and followed my usual routine. I caught the train from Rome to Monterotondo, albeit a bit earlier than usual. But my final goal was not to arrive at the lab – it was to make it to EMBL Heidelberg by hopping on a few more trains. As an EMBL PhD student, I have the chance to travel around the world to attend courses and present my research. But this great opportunity for my scientific and personal development comes with a price for the environment. Have you ever wondered how much carbon dioxide (CO2) you’re putting in the air every time you take a plane? Each one-way plane trip to Heidelberg emits approximately 152 kg of CO2 and 640 g of nitrogen oxides. Flights produce greenhouse gases – mainly CO2 – from burning fuel. These contribute to global warming when released into the atmosphere. Planes release 2% of global CO2 emissions, according to the International Air Transport Association (IATA). By choosing to travel by train rather than plane today, I am emitting 74% less CO2 to the environment.