(1) known catastrophic risks, whose probabilities can be assessed owing to their recurrence; (2) plausible catastrophic risks, which have never taken place and whose probabilities of occurrence are thus much more difficult to quantify satisfactorily; and (3) entirely speculative risks, which may or may not materialize.

health effects account for such a large part of these impacts and yet their monetization is notoriously difficult.

One of the most undesirable consequences of earlier melting of mountain snowpacks, of warmer and drier springs, rain-deficient summers, and reduced soil moisture will be a higher frequency and longer duration of wildfires.

Third, what follows afterwards is often equally unpredictable: a new long-lasting trend or a prolonged oscillation, a further intensification or an irreversible weakening?

Declining levels of soil organic matter, essential for the maintenance of soil fertility and structure, result from inadequate crop residue recycling, low or no manure applications, and no cultivation of green manures or leguminous cover crops.

number of potential catastrophes that could transform the world in a matter of months (extraordinarily virulent pandemics, a sequence of volcanic mega-eruptions) or even minutes (collision with a massive extraterrestrial object, accidental nuclear war), and a much longer array of worrisome trends (whose outcome can be a new world order or a histori

Total area strongly or partially imprinted by human activities is thus about 70 million km2, no less than 55% of nonglaciated land.

First, I address the most fundamental future shift in the global economy.

it offers the best way to power our imagination, to mobilize our creativity, and to deploy our considerable capacity for adapting to new, unforeseen and unforeseeable circumstances.