Planet Ark Environmental Foundation is an Australian non-profit environmental organization founded in 1992. Planet Ark works with partners in the public and private sectors to help find the simple ways in which their partners can reduce their impact on the planet. They focus on the environmental impacts of human consumption in the home, the workplace, and the community. It is best known for its high-profile recycling campaigns including 'Cartridges 4 Planet Ark', Australia's 'National Recycling Week', and the country's biggest annual community tree planting event, National Tree Day. The organisation is operated from its office in Sydney.