Cika wannan jumla: McAdams mai kare muhalli ne. Ta gudanar da shafin yanar gizo na rayuwar muhalli, GreenIsSexy.org, tare da abokanta biyu na tsawon shekaru biyar daga 2007 zuwa 2011. Gidan nata yana amfani da wutar lantarki mai sabuntawa ta Bullfrog. Tana tafiya a kusa da Toronto ta hanyar keke kuma ba ta da mota, amma tana tuki lokacin da ke Los Angeles saboda "birni ne mai wahalar hawa keke". Ta ba da gudummawa a Biloxi, Mississippi da Louisiana a cikin faɗuwar shekara ta 2005, a matsayin wani ɓangare na ƙoƙarin tsaftacewa bayan guguwar Katrina. McAdams ya zauna a kan TreeHugger / Live Earth alƙali a shekara ta 2007. Ta yi kira ga ba da gudummawa a lokacin Kanada don Haiti telethon a 2010. Ta shiga cikin Matter of Trust's "gashi boom" kokarin bin
2010 Gulf na Mexico mai zubar da man fetur. A cikin 2011, McAdams ya goyi bayan Foodstock, zanga-zangar adawa da wani babban dutsen dutsen da aka shirya a Melancthon, Ontario. A cikin 2013, ta yi bidiyo biyu na talla don Motsawar Abinci da Ruwa na Farko, da nufin adana filayen noma da tushen ruwa a Ontario, Kanada. A cikin 2014, ta ba da labarin fim ɗin "Take Me To The River", wanda ke bincika abin da ake yi don ƙoƙarin ceton koguna masu ban mamaki. A cikin 2021, ta shiga cikin bidiyon da Stand.earth ya samar yana kira ga gwamnatin British Columbia, Kanada da ta dakatar da yanke katako na karshe na tsohuwar gandun daji a fadin lardin.