The human
economy exchanges matter and energy with the larger
system of the earth, whereas the earth does not
exchange matter with the surrounding universe
(except for a few meteors). The earth receives solar
energy from outside and emits heat, and this energy
flow keeps up the processes of the system. Based on
this vision it makes sense to say that the human
economy can take up more or less dspaceT in the geobiosphere,
or, in other words, that it can appropriate
more or less of the biosphere; this dsizeT of the human
economy is what Daly refers to as the scale of the
economy