The measure of value called emergy is used to evaluate the flows of energy
and resources that sustain the biosphere including the economy of humans. A
donor system of value based on solar emergy required to produce things is
suggested as the only means of reversing the logic trap inherent in economi
c valuation, which suggests that value stems only from utilization by human
s. The stocks of natural capital and flows of environmental resources are e
valuated in emergy and related to Global World Product, Several emergy indi
ces are introduced as a means of evaluating sustainability of economies and
processes. The total emergy flux of the biosphere is composed of 32% renew
able flows of sunlight, tidal momentum and deep heat (it was 68% in 1950),
and 68% slowly-renewable and nonrenewable flows. An index of environmental
loading on the biosphere is shown to have increased about 4 times since 195
0, while an index of global sustainability suggests that overall, sustainab
ility of the global economy has precipitously declined.