1. School student Carla Ruiz lives in a hot country and has become very aware of the need to save water. 'Spring and autumn used to be quite wet, but these days it hardly rains at all,' she says. 'Nearly all the rivers have dried up, destroying all the wildlife in and around them, and no matter what we do they'll never be the same again. At least, though, we can use water more sensibly. That's why at home I recently decided to do simple things like making sure there are no dripping taps, or taps left on while I'm brushing my teeth or washing food. Within a few days I was regularly doing these things without even thinking, I know they made a difference because the water bills went down quite a bit. My parents noticed that so they started doing the same.'

2. Trainee manager, Vincent Owen, is doing his bit to save the planet by using less electricity around the home. 'I was talking to this guy at work and he told me that we waste a huge amount of energy every year by leaving things like the TV, DVD and computer on standby all the time, so nowadays I try to remember  — not always successfullyto switch them off at night. Incidentally, I've now got solar panels on the roof so that all the hot water is powered by the sun. That was a big investment, and it ended up well over budget, but I'm sure it'll pay for itself in the end.'

3. While Lin Chen is on a gap year, she is travelling round Europe with friends. 'We had intended to fly everywhere, she says, 'but when we worked out just how much extra pollution that would cause, we decided to do it by train instead. It was cheaper, too.' They began their tour in Greece: 'We all felt the obvious place to start was where European civilization began, so our first rail journey began in Athens. We travelled to Patras on the west coast, taking the ferry across to Bari in southern Italy. From there we took the overnight train to Paris, and a few days later we went on the Eurostar to London. We saw far more of the countryside than we would have done by plane.'

4. Tanya Petrova works in a restaurant with an extensive menu, but at home she will only eat local or seasonal food: 'I strongly believe that transporting food thousands of kilometers, or storing it under refrigeration for months on end, ultimately has a highly negative impact on the environment. I always try to buy food that is produced locally, and I have a special calendar to show me which kinds of food are in season so that I know what I'm buying is really fresh. Apart from the environmental considerations, I'm convinced the food I eat, which has far fewer chemicals in it, helps me avoid the kind of illnesses that seem to be so common these days.'