In addition to studying the ozone layer and climate change, he popularized the term Anthropocene to describe a proposed new epoch in the Quaternary period when human actions have a drastic effect on the Earth.

[9] After completing military service, in 1958 he married Terttu Soininen, a Finnish university student whom he had met a few years earlier and moved with her to Gävle, a tiny city 200 km north of Stockholm where he took a job at a construction bureau.

[9] His thesis was well-received and led to a post-doctoral fellowship at the Clarendon Laboratory of the University of Oxford, on behalf of the European Space Research Organisation (ESRO), the precursor of ESA.

In the following year, Crutzen and (independently) Harold Johnston suggested that NO emissions from the fleet of, then proposed, supersonic transport (SST) airliners (a few hundred Boeing 2707s), which would fly in the lower stratosphere, could also deplete the ozone layer; however more recent analysis has disputed this as a large concern.

[17] In 1974 Crutzen received a prepublication draft of a scientific paper by Frank S. Rowland, professor of Chemistry at University of California, Irvine, and Mario J. Molina, a postdoctoral fellow from Mexico.

[27] On his death, the president of the Max Planck Society, Martin Stratmann, said that Crutzen's work led to the ban on ozone-depleting chemicals, which was an unprecedented example of Nobel Prize basic research directly leading to a global political decision.

[31]Steve Connor, Science Editor of The Independent, wrote that Crutzen believes that political attempts to limit man-made greenhouse gases are so pitiful that a radical contingency plan is needed.

In a polemical scientific essay that was published in the August 2006 issue of the journal Climatic Change, he says that an "escape route" is needed if global warming begins to run out of control.

If this artificial cooling method actually were to work, it would reduce some of the effects of the accumulation of green house gas emissions caused by human activity, potentially extending the planet's integrity and livability.

[33] In January 2008, Crutzen published findings that the release of nitrous oxide (N2O) emissions in the production of biofuels means that they contribute more to global warming than the fossil fuels they replace.

[35] They theorized the potential climatic effects of the large amounts of sooty smoke from fires in the forests and in urban and industrial centers and oil storage facilities, which would reach the middle and higher troposphere.

They concluded that absorption of sunlight by the black smoke could lead to darkness and strong cooling at the earth's surface, and a heating of the atmosphere at higher elevations, thus creating atypical meteorological and climatic conditions which would jeopardize agricultural production for a large part of the human population.