J.R. McNeill
Georgetown University

In this article I have offered three generalisations about global environmental history in the two centuries since 1800. To review, the first was that the era since 1800 has been, and remains, first and foremost, the age of fossil fuels.

The huge expansion in energy availability and use served as the most important catalyst for environmental changes of many sorts.

The second generalisation was that these centuries were also characterised by unprecedented rates of population growth and urbanisation, which also had remarkable environmental effects. These two macro-trends reinforced one another: more energy use helped bring about more people, and more people meant more demand for energy.

The third generalisation was that within these two centuries, the period after about 1950 appears to have a grander scale and scope, a higher speed, than anything which went before. It has been, and remains, the most tumultuous time in the last 70,000 years of relations between humankind and the rest of the biosphere. 20

20I say 70,000 years because about 71,000 years ago a volcanic eruption (Toba in Sumatra) at least 40 times larger than anything in historical times apparently brought the human race to the brink of extinction – or so some scholars read the mitochondrial DNA evidence.