▁the ▁media , ▁and ▁highly ▁popular ▁accounts ". ▁ ▁Content ▁ ▁Cl imate ▁spir als ▁use ▁changing ▁distance ▁from ▁a ▁center ▁point ▁to ▁represent ▁change ▁of ▁a ▁dependent ▁variable ▁( arch et yp ically , ▁global ▁average ▁temperature ). ▁The ▁independent ▁variable , ▁time , ▁is ▁broken ▁down ▁into ▁months ▁( re present ed ▁by ▁constantly ▁changing ▁rot ational ▁angle ▁about ▁the ▁center ▁point ) ▁and ▁years ▁( line ▁colour ▁that ▁evol ves ▁as ▁years ▁pass ). ▁ ▁Haw kins ▁explained ▁that ▁in ▁his ▁implementation , ▁colours ▁represent ▁time : ▁pur ple ▁for ▁early ▁years , ▁through ▁blue , ▁green ▁to ▁yellow ▁for ▁most ▁recent ▁years . ▁He ▁made ▁the ▁graphics ▁in ▁M AT LAB ▁and ▁used ▁the ▁" vir id is " ▁colour ▁scale , ▁conscious ▁of ▁choosing ▁a ▁colour ▁scale ▁that ▁makes ▁the ▁graphics ▁leg ible ▁to ▁colour ▁blind ▁view ers . ▁ ▁As ▁the ▁graph ic ▁includes ▁red ▁concent ric ▁circles ▁den oting ▁temperature ▁changes ▁of ▁ 1 . 5 ° C ▁and ▁ 2 . 0 ° C , ▁Haw kins ▁explained ▁that ▁" the ▁relationship ▁between ▁current ▁global ▁temper atures ▁and ▁the ▁intern ation ally ▁discussed ▁target ▁limits ▁is ▁also ▁clear ▁without ▁much ▁complex ▁interpretation ▁needed ". ▁R ia ▁Mis ra ▁wrote ▁in ▁G iz mod o ▁that ▁the ▁graph ic ▁" lets ▁the ▁noise ▁of ▁tiny ▁variations ▁fade ▁into ▁the ▁background ▁while ▁still ▁show c asing , ▁very ▁simply , ▁the ▁und eni able ▁tr end ". ▁ ▁Descri bing ▁how ▁global ▁war ming ▁" app ears