Given the current ecological crisis, all professionals handling ecologically hazardous chemicals should have a proper understanding of the physicochemical effects on our ecosystem in order to rationally justify professional choices. Although CO2 is the most important greenhouse gas, other volatile molecules, such as volatile anesthetics, have a much stronger effect per gram.

An understanding of the scientific background enables anesthesiologists to responsibly select hypnotics in order to reconcile optimal anesthesia with ecological responsibility. Emissions of greenhouse gases by an individual anesthesiologist who disregards these insights can be higher than the total annual greenhouse gas emissions of more than 100 average Chinese or European residents (8.000 kg CO2 /year).

In a universe with a background temperature of -270°C, the earth orbits the sun with a surface temperature of 6000°C. The stable temperature on earth, necessary for our ecosystem results from a delicate interaction of electromagnetic radiation with molecules in the atmosphere. A minimal disturbance of this fragile effect of incoming and outgoing energy results in a massive net flux of energy. The current disturbance of this equilibrium generates a net energy flux of more than 300,000 Gigawatts, or the equivalent of 5 Hiroshima-level nuclear explosions per second. This heat accumulation is largely harnessed to heat up oceans and melt ice caps.

The degree to which gases produce a greenhouse effect is expressed in global warming potential. The extent to which a particular volatile anaesthesic contributes to global warming is determined by its degree of absorption within certain windows of the electromagnetic spectrum, the atmospheric half-life, and the clinically used dose.

A clear understanding of the underlying physics and chemistry shows that respecting three simple rules of thumb allows reducing the greenhouse effect of anesthesia by more than 99%: avoid desflurane, avoid N2O, and use minimal fresh gas flow.