世界地球日
Two separate groups formed to sponsor Earth Day events in 1990: The Earth Day 20 Foundation, assembled by Edward Furia (Project Director of Earth Week in 1970), and Earth Day 1990, assembled by Denis Hayes (National Coordinator for Earth Day 1970). Senator Gaylord Nelson, the original founder of Earth Day, was honorary chairman for both groups. The two did not combine forces over disagreements about leadership of combined organization and incompatible structures and strategies. Among the disagreements, key Earth Day 20 Foundation organizers were critical of Earth Day 1990 for including on their board Hewlett-Packard, a company that at the time was the second-biggest emitter of chlorofluorocarbons in Silicon Valley and refused to switch to alternative solvents. In terms of marketing, Earth Day 20 had a grassroots approach to organizing and relied largely on locally based groups like the National Toxics Campaign, a Boston-based coalition of 1,000 local groups concerned with industrial pollution. Earth Day 1990 employed strategies including focus group testing, direct mail fund raising, and email marketing.