Global Catastrophes and Trends: The Next Fifty Years

another category of discontinuities deserves at least a brief acknowledgment, that of epoch-making technical developments. Incremental engineering progress (improvements in efficiency and reliability, reduction of unit costs) and gradual diffusion of new techniques (usually following fairly predictable logistic curves) are very much in evidence, bu

(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.

(growing a kilogram of wheat needs about as much water as does the production of a kilogram of computer hardware, about 1.5 tons),

All affluent countries have seen a relative decline in manufacturing, but in the United States these losses have gone farther than in Europe or Japan. The sector employed about 30% of the labor force during World War II, but by 2005 the share was less than 12%, compared to 18% in Japan and 22% in Germany

Atlanta's acute asthma attacks and pediatric emergency admissions during the Olympic Games of 1996 (when measures that reduced traffic by some 30% were in effect) with the same periods during the previous and the following year (Friedman et al. 2001): asthma attacks fell by 40% and pediatric emergency admissions declined by 19%.

higher atmospheric CO2 concentrations result in lower evapotranspiration losses from vegetation,

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.

poleward range shifts averaging 6.1 km per decade and advancement of spring events surpassing two days per decade.

best all-day rates in 2005 were on the order of 30 W/m2). All other renewables have low (<10 W/m2), or very low (<1 W/m2) production power densities. Low extraction power densities would be the greatest challenge in producing liquid fuels from phytomass. Even the most productive fuel crops or tree plantations have gross yields of less than 1