Swedish scientist first concluded Svante Arrhenius it was first mentioned by Svante Arrhenius in 1896 Swedish scientist the Greenhouse Effect is, in fact, a theory before global warming was more widely accepted was not entirely understood at the time way back in 1896 Swedish scientist Svante Arrhenius www.lenntech.com... Swedish scientist in the late 1800s by Arrhenius the Greenhouse Effect is, in fact, a theory Svante Arrhenius the Greenhouse Effect is, in fact, a theory Svante Arrhenius www.lenntech.com... Swedish scientist first proposed by Svante Arrhenius in 1896