We should also know that 'greed' is little related to the environmental crisis. The two main factors are population pressures, especially the pressures of large metropolitan populations, and the desire to bring a decent living with the lowest possible cost to the largest possible number of people. The environmental crisis is the result of success in cutting down the morality of infants ( which has given us the population explosion), success in increasing farm output sufficiently to prevent mass famine, success in getting people out of the tenements of the 19th century city and into the greenery anti privacy of single family home in the suburbs (which has given us urban sprawl and traffic jams). The environmental crisis, in other words, is the result of doing too much of the right sort of thing at large. To overcome the problems that success always creates, one mast build on it. But where to start? Cleaning up the environment requires determined, sustained effort with clear targets and deadlines it needed, above all, concentration of effort. Up to now we have tried to do a little bit of everything, what we ought to do first is to draft a list of priorities. This passage assumed the desirability of ______.