Hōʻike ka hōʻike noiʻi me ka emi ʻana o ka ulu ʻana o ka heluna kanaka a me ka ulu ʻana o nā ʻoihana hoʻokele waiwai, hiki ke lohi ka ulu ʻana o ka noi aggregate honua no nā mea kūʻai aku a piʻi aʻe ke koi no kekahi mau waiwai.Eia kekahi, hiki ke paʻakikī ka hoʻololi ʻana i ka ikehu maʻemaʻe.ʻO ke kūkulu ʻana i ka ʻenehana ikehu hou a me ka hana ʻana o nā kaʻa uila e koi i nā ʻano metala kūikawā, a ke piʻi nei ka koi no kēia mau metala i nā makahiki e hiki mai ana, e hoʻonui ana i nā kumukūʻai a lawe mai i nā pōmaikaʻi nui i nā ʻāina e lawe aku ana.ʻOiai ua lilo ka ikehu hou i ka ikehu haʻahaʻa haʻahaʻa loa ma nā ʻāina he nui, e mau ka nani o nā wahie mōʻalihaʻi, ʻoi aku hoʻi ma nā ʻāina me ka nui o nā mālama.I ka wā pōkole, ma muli o ka lawa ʻole o ka hoʻopukapuka ʻana i nā ʻenehana haʻahaʻa-carbon, ʻoi aku ka nui o ka pilina hoʻolako-koi o nā huahana ikehu ma mua o ka lako, no laila e hoʻomau ke kumukūʻai kiʻekiʻe.