We have a new estimate of the annual worth of the Biosphere's essential goods and services, such as climate regulation, flood control, oxygen production, soil formation, and water supply. That value, thirty-three trillion U.S. dollars, is twice the cultural world's annual economic output, and fourteen percent of it is the work of forests. When asked to comment, one ecologist said, "I don't see much hope for a civilization so stupid that it demands a quantitative estimate of the value of is own umbilical cord." I disagree, for I've found that people learn best in familiar terms and might appreciate natural values translated into money.

Nevertheless, I'd add at least three additional calculations for a realistic evaluation. First, the Biosphere's annual negative value to culture requires counting losses from floods, tornadoes, and other natural catastrophes. Second, we must assess the negative value of human folly that triggers and exaggerates catastrophes, for instance building houses in floodplains and cutting trees on slopes. Third, culture's adverse impacts on nature's positive life support must be accountable. Perhaps a net value compared to the gross will be sufficiently scary to awaken humanity before its real nightmares begin.