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Support farmers who avoid chemical pesticides and can deliver produce to market without significant fuel consumption (and pollution).  Every bit of pollution prevention helps endangered species, and you will help make organic farming the socially and financially sensible choice for growers. If your municipality has a recycling program, make full use of it. If there isn't a program, work to create one.  Keep as much of your waste out of landfills as possible.   Landfills take up valuable space and some waste (like plastic bags and bottles) inevitably seems to make its way into wild habitats or the huge swirls of trash found out at sea, with negative consequences to animal life. Buy products and food without packaging whenever possible. Take your own bags to the store. This will reduce the amount of garbage and waste you produce, not to mention the pollution resulting from the creation and distribution of this packaging.  Whales and tigers will thank you. Start an initiative to share specialty tools and seldom-used household items among neighbors. There are good examples of people working with their local libraries to have a tool lending section. Donate used toys, books, games, clothing, etc., to hospitals, shelters, daycares, or charities. Before throwing something out, consider creative ways of reusing it.  A toilet bowl flower pot may not be your style, but that old, beat-up kitchen table might make a nice little workbench. Walk or ride a bicycle to work or the market.  It's good for your body and produces zero emissions that negatively impact earth's delicate climate balance.  Take public transportation when available.  When you do use the car, drive more slowly.  Animal-vehicle collisions are on the rise as human and animal habitats increasingly overlap, and this is a particular threat to certain endangered species. Unplug televisions, computers, and other items that still draw electricity even when turned off. This will stop the "vampire" energy drain of these devices.  You will cut pollution that damages the habitats of endangered species while also saving money.  Not a bad deal.  Make it a habit in your own life and share it with others.  Tell them you can save them a buck and help the polar bears. Turn off the tap while you brush your teeth and use water-saving devices on your toilet, taps and shower head.  Fix leaky pipes and faucets promptly.  Even a small drip can waste large amounts of water over time.   Use drip irrigation or other water saving devices in the garden. If legal in your area, consider installing a "grey water" system that uses water from showers and sinks in the garden. If you are hardcore, install a composting toilet. Growing human demand for water leads to changes in freshwater ecosystems, beyond just reducing water levels.  For instance, the building of dams to make reservoirs can prevent salmon from reaching their spawning grounds.
Shop for locally-grown organic produce. Reduce, reuse, and recycle. Consider alternatives to driving. Save energy by turning off lights and electrical appliances when not in use. Don't waste water.