To limit global warming below 2°C, a drastic overall reduction from current CO2 emissions is needed. We argue that scientists should also participate in this effort in their professional activity and especially Earth scientists, on the grounds of maintaining credibility and leading by example. The strategies and measures to reach a low-carbon scientific activity require detailed estimates of the current footprint of laboratories. Here, we present the footprint of six laboratories in Earth, environmental and space sciences, representative of the AGU community, with a comprehensive scope also including international research infrastructures. We propose a novel method to attribute the footprint of any research infrastructure to any given research laboratory. Our results highlight that most laboratories have annual footprints reaching 10-20 tonnes CO2 equivalent per person (tCO2e.p-1), dominated by infrastructures and specifically satellites in three cases (with footprints up to 11 tCO2e.p-1 or 60%), while air-travels and purchases remain within the top three sources in all cases (2-4 tCO2e p-1 or 10-30% each). Consequently, footprints related to commuting and laboratory functioning, about 2 tCO2e.p-1 (20%) or less, are relatively modest compared to infrastructures, purchases and air-travels. Thus, reduction measures ignoring infrastructures may not be able to achieve reductions larger than 20 to 35% even with flight quotas and a substantial reduction of purchases. Finally, we also discuss how a deeper transformation of scientific practices, away from a fast science ideal, could make Earth and environmental sciences more sustainable and at the forefront of a rapid and drastic social bifurcation.