Abstract: A method and system for dividing and trading of emission reduction credits between linked websites and advertisers is provided. A general emission reduction credit inventory and Portfolios with emission reduction credits can be created in a Sustainable Ad Network platform. The emission reduction credits of the inventory or Portfolios can be divided into micro emission reduction credits. A website or advertiser can be linked to the Sustainable Ad Network platform and a unique emission reduction credit account can be created for each linked website, advertiser or person. A sustainable advertisement can be associated to each linked website, and the sustainable advertisement can be placed on each linked website. When a person clicks, views, or interacts with a sustainable advertisement, micro emission reduction credits can be subtracted from the general emission reduction credits inventory, and added or credited to the emission reduction credit account of the website, advertiser or person.