▁succession ▁results ▁in ▁efficient ▁explo itation ▁of ▁available ▁resources . ▁However , ▁even ▁modern ized ▁cities ▁may ▁still ▁be ▁in ▁the ▁earliest ▁stages ▁of ▁a ▁succession ▁that ▁may ▁take ▁centuries ▁or ▁mill enn ia ▁to ▁complete ." ▁How ▁much ▁energy ▁is ▁used ▁in ▁rec y cling ▁also ▁depends ▁on ▁the ▁type ▁of ▁material ▁being ▁rec yc led ▁and ▁the ▁process ▁used ▁to ▁do ▁so . ▁Al umin ium ▁is ▁generally ▁agreed ▁to ▁use ▁far ▁less ▁energy ▁when ▁rec yc led ▁rather ▁than ▁being ▁produced ▁from ▁scratch . ▁The ▁E PA ▁states ▁that ▁" re cy cling ▁al umin um ▁can s , ▁for ▁example , ▁saves ▁ 9 5 ▁percent ▁of ▁the ▁energy ▁required ▁to ▁make ▁the ▁same ▁amount ▁of ▁al umin um ▁from ▁its ▁vir gin ▁source , ▁b aux ite ." ▁In ▁ 2 0 0 9 , ▁more ▁than ▁half ▁of ▁all ▁al umin ium ▁can s ▁produced ▁came ▁from ▁rec yc led ▁al umin ium . ▁Similarly , ▁it ▁has ▁been ▁estimated ▁that ▁new ▁steel ▁produced ▁with ▁rec yc led ▁can s ▁reduces ▁green house ▁gas ▁em issions ▁by ▁ 7 5 %. ▁ ▁Econom ist ▁Steven ▁Land s burg ▁has ▁suggested ▁that ▁the ▁sole ▁benefit ▁of ▁reducing ▁land fill ▁space ▁is ▁tr ump ed ▁by ▁the ▁energy ▁needed ▁and ▁resulting ▁poll ution ▁from ▁the ▁rec y cling ▁process . ▁O thers , ▁however , ▁have ▁calculated ▁through ▁life - cycle ▁assess ment ▁that ▁producing ▁rec yc led ▁paper ▁uses ▁less ▁energy ▁and ▁water ▁than ▁har vest ing ,