Severe flooding, and now a brown cloud of pollution over Asia. The Earth Summit, which begins later this month in Johannesburg, has never been more important, says STEPHEN LEWIS. But is anyone listening?

IF WE still had any lingering doubts about our ability to damage the planet we live on, the Asian brown cloud must surely have dispelled them. The three-kilometre deep blanket of sooty pollution stretching across southern Asia threatens to inflict untold economic damage on the region and put hundreds of thousands of people at risk, scientists have warned.

The toxic cloud is a mass of ash, acids, chemical droplets and other particles.

It is already disrupting weather systems, triggering droughts in some areas and floods in others. And it is entirely man's work.

Klaus Toepfer, executive director of the United Nations Environment Programme, told a news conference in London: "The haze is the result of forest fires, the burning of agricultural wastes, dramatic increases in the burning of fossil fuels in vehicles, industries and power stations, and emissions from millions of inefficient cookers burning wood, cow dung, and other bio-fuels."

Mr Toepfer warns the cloud has global implications. "A pollution parcel like this, which stretches three kilometres high, can travel half way round the globe in a week," he said.

It's no use simply blaming the developing countries of Asia for the brown cloud, either. Much of the illegal deforestation of these countries - a slash-and-burn process which is contributing to the cloud - is being done on behalf of multi-national companies, many with bases in the UK, points out Friends Of The Earth's Mike Childs. And it is being done to produce paper that our wasteful, throw-away society simply chucks out after is has been used once, rather than recycling it.

So we all share responsibility for this latest environmental disaster. Long before we had heard about the cloud, we had all been worrying about global warming, and yet developed countries such as Britain and the USA - known as the biggest greenhouse polluter on the planet - hardly distinguished themselves by their efforts to 'clean up' their act.

The relationship between man's economic and industrial activity and the pollution of the environment we live in has always been a complex one. If anything, the brown cloud has further muddied scientists' attempts to understand that relationship.

It is now clear it is not just greenhouse gases which represent a long-term threat, but the cocktail of soot, pollutants and other particles that result from our activities, too.

"We used to think the human impact on climate was just global warming," said Professor V Ramanathan of the US Scripps institution of oceanography in a recent interview.

"Now we know it is more complex. The brown cloud shows man's activities are making climate change more unpredictable everywhere. Greenhouse gases such as carbon dioxide are distributed uniformly, but the particulates in the cloud add to unpredictability worldwide."

Scientists are reluctant to attribute individual weather phenomena - such as, for example, the recent floods in Scarborough and Filey or the torrential flooding in Russia and continental Europe - to the brown cloud, saying more research is needed. But they do believe there are many interconnections between the haze cloud and global warming.

"Some places will see more drying, others more rainfall. Greenhouse gases and aerosols may be acting in the same direction or may be opposing each-other," said Professor Ramanathan.

If there were ever a time to clean up our act on a global scale, it is now. The good news about the brown cloud is that it is man made, so it can be eliminated, said Mr Toepfer. But it won't be easy. It will need better burning technologies, cleaner traffic and more sustainable energy.

No better place at which to get to grips with those issues than the 2002 Earth Summit, which begins on August 26 in Johannesburg. The summit, says Mike Childs - Friends Of The Earth's Earth Summit co-ordinator - represents a once-in-a-decade chance to tackle the issues on a global level.

Which only makes the apparent lack of ambition of many of the world leaders who will be there - Tony Blair among them - all the more disappointing.

The problem appears to be a simple lack of political will or courage, and a fixation with short-term economic gain.

The US does not to want to risk upsetting the 'fossil fuel companies' while, according to Mark Hill, York and Yorkshire co-ordinator of the Green Party, Tony Blair spends more time listening to big business than he does his own environment minister, Michael Meacher. It is hard to believe that is not true. Mr Meacher was dropped from the UK delegation, before being hurriedly reinstated. And included as part of the UK team in Johannesburg will be business leaders with dubious green credentials, leading to fears of the summit being 'hi-jacked' by big- money interests.

Mark Hill believes Mr Blair's government lacks the 'political courage and conviction' to do anything about environmental degradation. "Instead, they are focusing on what they think will deliver short-term economic gain," he says. "They are not thinking about the long-term interests of its people."

Mr Meacher agrees. At the weekend he said he was like a "lone voice in the wilderness" over the environment.

"I make no bones about it. I don't think the Government as a whole is yet ready to take the magnitude of decisions I think are necessary," he said.

For that, we must all take some responsibility. Tackling global warming will hurt. It will mean cutting the amount of fuel we use in our homes and cars: it will probably mean more expensive power if we are to invest in 'clean' sources of power such as wind and waves; it will mean us waking up to the need to recycle our rubbish and funding impoverished nations so they can begin to clean up.

If we're not prepared to accept such measures you can hardly blame a government which relies on our vote for shying away from them.

Yet something must be done. It is too early yet, says Mike Childs, to write the summit off. "We need leadership, and I'm hoping Tony Blair will provide some of that," he says. "But if we miss this chance, does that mean we have to wait another ten years?"

Mark Hill has a grim warning about what will happen if we don't wake up.

"Global warming is not going to be a problem for us anything like as much as for our children and our children's children," he says.

"The writing is on the wall. The Government should have the vision to think about the people who are going to inherit the consequences of its decisions."

For our children's sake, let's hope Tony Blair is listening.

Updated: 10:37 Tuesday, August 13, 2002