Janet Street-Porter: A song by Madonna won't save the world

The egotism of pop stars never fails to amaze. As record sales plummet, they continue to search for ways to promote their wares, and the latest scam is a series of concerts designed to "raise our awareness" of climate change, called Live Earth scheduled to take place over 24 hours in seven locations on seven continents, on July the seventh this year.

Is there anyone in the civilised world who is not aware of global warming by now? You can't pick up a newspaper, turn on the television, or walk down the street without being bombarded with information about your carbon footprint, the urgent need to recycle and consume less. The only people not fully on message are our elected leaders, and it seems highly unlikely, given their past efforts, that a couple of tunes by Madonna and the Red Hot Chili Peppers will cause an immediate brainstorm and rush to action.

Using pop music as a tool of social change has limited results, and you could argue that the people who consume the most contemporary music are those most aware of the big issues facing the planet. The young and the poor are traditionally the people who contribute the biggest proportion of their time and money to good causes. And, by the way, there's not one recording artist in history who has not sold more records as a result of appearing in one of these charity shows beamed live to billions of people around the world. Beats a couple of blogs on Myspace, doesn't it!

Live Earth is controversial because it involves flying hundreds of musicians all over the place, even though the organisers claim that all this travel will be off-set, and that each venue will be designed to have a minimum environmental impact, using energy generated on-site.

This is pure piffle - 100,000 people in Wembley Stadium (having paid £55 a ticket) are going to generate a hell of a lot of waste paper, and what about the water used in the flushing toilets? Is fast food going to be handed out to those bringing their own cutlery and plates? Is the stage lighting running on wind power or are we going to be asked to hold up candles

The organisers say "it enables us to reach out to large numbers of people who will be encouraged to learn how they can reduce their carbon footprint". We can find that out without leaving the home, via the internet - and evidence suggests that ordinary members of the public are taking to recycling, changing the way they travel and doing their bit for the environment in all sorts of small ways already. Like the organic movement, green living is starting to really take off at grassroots level, and what we don't need is a patronising failed Presidential candidate and a load of pop stars having a party we have to pay to attend to ram a message home.

Many of the organisers were involved in Live 8, held immediately before the G8 summit at Gleneagles in July 2005. The most important aim of this event - to "make poverty history" - has been a conspicuous failure, in this country at least.

At the end of last month, new figures revealed that poverty (those living on less than 60 per cent of the average income) had increased in the UK for the first time in almost a decade, from 12.1 million in 2005 to 12.7 million in 2006. The number of children living in poverty in the UK now numbers 3.8 million.

Well done everyone! It really shows that when pop stars chant a mantra, politicians might tap along to the beat, but they aren't acting on the message.

The gym slip goes glamorous

Lily Cole, one of our most successful young models, has just taken her first acting role before starting a degree course at Cambridge University this autumn, reading English and Politics. Ms Cole has wisely decided not to opt for the cheeky suspenders and stockings of the other St Trinian schoolgirls in the new version of the classic comedy being made by Ealing Studios. Instead the Vogue cover girl cuts a demure figure as the school swot in granny glasses, knee-length skirt and mandatory iPod.

With Rupert Everett playing Alastair Sim's old role of the headmistress, Russell Brand as Flash Harry, Celia Imrie as Matron and Colin Thwaites as the local MP, the film's casting promises plenty of laughs. It's only a matter of time before fashion editors deciding that gym slips and blazers are the latest thing for this autumn, and we'll probably soon see Lily getting paid for wearing them on the pages of the glossies.

* The fine weather has meant that many of us have spent time relaxing in the back garden, but new research reveals that far from being tranquil retreats from the pressures of life, the garden can be a source of conflict with the neighbours. Top of the list are irritating wind chimes and smoke from barbecues. I can have a row over our garden any day - we've already practically come to blows over whether to lay paving, whether to plant a herb garden, where to site a bird table and whether to have a pond or not. And there's no neighbours involved, just the two residents of our house. At least we didn't have a fight in the public arena of the local garden centre - it took place in the devastated area that is our garden now the builders have left. And at this rate, it will still look the same in several months' time.

More from Janet Street-Porter