  I examine the applicability of ecological concepts in discussing issues
related to space environmentalism. Terms such as "ecosystem"", "carrying
capacity"", and "tipping point" are either ambiguous or well defined but not
applicable to orbital space and its contents; using such terms uncritically may
cause more confusion than enlightenment. On the other hand, it may well be
fruitful to adopt the approach of the Planetary Boundaries Framework, defining
trackable metrics that capture the damage to the space environment. I argue
that the key metric is simply the number of Anthropogenic Space Objects (ASOs),
rather than for example their reflectivity, which is currently doubling every
1.7 years; we are heading towards degree scale separation. Overcrowding of the
sky is a problem astronomers and satellite operators have in common.
