The earth is sick and the present work explains how
it gets ill and how serious the decease is. It is shown that the illness
originates in over dense population since present population is 7.6 billion
while 1.3 billion is the breakeven point of the earth for CO2 metabolism and 6.7 billion is the upper limit to maintain a quasi-equilibrium
state for the metabolism. More and more greenhouse gases emit into atmosphere
from underground and undersea, and warming up process is accelerated. Utilization of clean energy cannot save the earth, but to pray a
little ice age coming soon. What humanity can and should do is to use
zero-emitted coal power and change the fertility rate to negative.