A third of all household rubbish can be rotted into compost instead of lying on landfill sites, so why not build a compost bin of your own? All you need is a wooden or plastic bin, and lots of fruit and vegetable scraps, leaves, weeds and grass.

Put it all in the bin, mix it around, add some water unless it's already wet (and newspaper if it's mostly kitchen waste) and cover, to keep everything dark and protected from the weather. Then just wait six months to a year (it will work faster if you keep opening it and mixing it around) and it will have transformed into a rich dark earth - compost! - which helps plants and crops grow. Remove the compost from the bottom and add more waste to the top, and it will continue to transform as long as you have rubbish to throw away…

and see environmental concerns aren't the hot topic of the city, why not create a nature reserve in your back garden? Wherever you live, you can attract all kinds of animals by providing them with the right plants as a source of food and shelter. Building a water source like a pond will attract birds and even frogs and toads, wild flowers attract butterflies, and planting shrubs, which produce berries and nuts, might bring small mammals like mice and voles. If you haven't got space for a nature reserve behind your house, build one on top! City dwellers the world over are building gardens on their roofs.

On 24 August 2000, a Bryde's whale died on the coast of Australia, in Trinity Bay, near central Cairns. An autopsy found that the whale's stomach was tightly packed with plastic, including supermarket bags, food packages, bait bags, three large sheets of plastic and fragments of rubbish bags, but no food. More than 100,000 whales, seals, turtles and birds die from plastic packaging every year and there are so many plastic bags caught in the trees in South Africa, the people have ironically crowned them their national flower.

Ireland has levied a small charge on each plastic bag to stop shoppers using them every time they go to the supermarket. Use of the stores' plastic bags has dropped dramatically as people bring their own. Between us we are using between 500 billion and a trillion every year. Does your country need to introduce laws to convince you? Just bring your own reusable bags along to the shops and protect our world from the plastic menace.

ART BY DEIA SCHLOSBERG/PCI