Writing about the discussions with top industrialists that were held by the US president Herbert Hoover during the Great Crash of 1929, J K Galbraith observed that such meetings were called "not because there is business to be done, but because it is necessary to create the impression that business is being done". I can think of no better description for the G8 summit, the annual gathering of leaders of the wealthiest industrialised nations.

This year's summit, from 8-10 June, will be held on Sea Island, off the coast of Georgia in the US. It was supposedly picked because of its "reputation for gracious hospitality and its beautiful natural setting". In reality, it was selected so that the world's leaders can be kept away from protesters. Patrols will monitor every road, river, beach and airstrip. Three airports will be closed to general aviation and (you can find these details on www.secretservice.gov) people will be barred from "all waters of the Atlantic Ocean from the baseline of Sea Island and Jekyll islands extending seaward to a distance of three nautical miles, as well as waters on the Hampton River, Jones Creek, Lanier Island, St Simons Sound".

Behind all this security, will the G8 be doing humanity in general any good? Its past record suggests not, unless you count filling media archives with photographs of men in suits as beneficial.

No doubt terrorism will be on this year's agenda. Terrorism is a regular tick-box at G8 meetings. The frequency with which it gets in the way of anything good being done is remarkable. In 1996 Jacques Chirac, hosting the summit in Lyons, promised that it would mark a fundamental realignment between the world's rich and poor. Third-world debt was just coming into view again. Then a bomb went off in one of America's several backyards. Someone found an old 50-point plan to tackle terrorism and that was all they talked about - apart from the bag of freebies (in this case including wine and a Philippe Starck radio) that the host countries always give to delegates. At least the freebies were taken home. The anti-terror and anti-poverty plans were forgotten.

So how does the G8 measure up on other issues?

Aid A target for countries to give 0.7 per cent of their gross national product in aid has been pledged repeatedly since 1970 (before the G8 there was a G7). As the Organisation for Economic Co-operation and Development (OECD) observed in 2000, if this had been met, "the mass poverty and humanitarian emergencies which persist in many parts of the developing world might have been largely avoided". In fact, the US gives 0.14 per cent of GNP, Italy 0.16 per cent, Japan 0.2 per cent, the UK 0.34 per cent. "With an extra $50bn of aid urgently needed to save lives and reduce global poverty, donors managed a paltry $2.3bn extra last year," says Romilly Greenhill of the development agency ActionAid.

Debt Summits have repeatedly promised a "lasting exit" from unpayable debt; in Cologne five years ago, the G8 pledged $100bn worth of relief for 41 countries. Since then, 13 countries have had $18.2bn of debt cancellation. According to Jubilee Research, a continuation of the Jubilee 2000 debt campaign, all these countries retain an unsustainable debt burden even after relief. Comparing it to a losing game of snakes and ladders, Jubilee Research concludes: "It appears that creditors have done their best to ensure that as few countries as possible trickle through the net of debt cancellation."

Trade Much the same promise is made every year: in 2003, for example, the G8 pledged "to provide fairer, less distorted, more transparent and more predictable conditions for world trade". In fact, the US, Canada and Britain, big hitters in all world trade negotiations, support a distorted free-trade model that aims to open the markets of poor countries to foreign goods while retaining protectionist trade barriers for developed countries. Though it is said we need more unregulated international trade to tackle poverty, increased trade liberalisation has, in fact, failed the poorest. In the developing world, only a narrow elite benefits.

The UN trade agency Unctad predicts that the numbers living in extreme poverty (on less than $1 per day) will rise from 334 million now to 471 million in 2015. Which is supposed to be the target year for exactly the opposite - halving the number of people in poverty.

At this summit, as at previous ones, the G8 will ignore the chronic long-term depression in prices of commodities that poor countries depend on, such as cotton, tea and sugar. Falls of 25-40 per cent in the space of five years suggest that the best thing the G8 could do would be to resurrect international initiatives to stabilise prices. But that would undermine the dogma at the heart of economic globalisation.

Environment Apart from a few civil servants who act as "sherpas" for the G8, the annual summit lacks a permanent secretariat. So the heads of state can promise anything they like every year, safe in the knowledge that no mechanism will hold them to account. So when the G8 set up a task force on renewable energy in 2001 it looked like a rare positive act. Currently only between 1 and 3 per cent of energy investment in developing countries goes to renewables. The G8 offered a double win: a contribution to preventing climate change and help for the world's 1.6 billion people who have no access to electricity. Energy is the forgotten human development issue, given that it is needed for everything from health and education to drinking water and cooking.

The task force recommended phasing out subsidies to fossil fuels - on which the OECD countries spend more than $70bn per year, about 50 per cent more than they give in overseas aid - and getting renewable energy to two billion people by 2010. This commitment was overdue, unavoidable even, because if developing countries were ever to approach G8 levels of per capita carbon emissions, uncontrollable global warming would become a certainty.

But nothing significant has happened since 2001. When the G8 chair summarised action in 2003 at a summit in Evian, France, the reference to getting renewable energy to two billion people had disappeared.

This last example is a perfect illustration of Galbraith's point: "Such meetings are more than a substitute for action. They are widely regarded as action." Like many others, I have wasted time on following G8, hanging on every word of its annual communiques. It deserves no such deference.

The members of the G8 - the United States, Canada, Britain, Japan, Germany, Italy, France and Russia - present themselves as benevolent international creditors. But their disproportionately high use of fossil fuels makes them global ecological debtors, stealing the environmental capital of poor countries to support their own development. They are parasites.

By choosing isolated summit venues that are hard for protesters to reach (the meeting in Canada two years ago was up a mountain), they can continue to pretend to each other that they are being useful. Perhaps the rest of the world should set up a new summit. Pull together the eight countries most affected by global warming, places such as Bangladesh and Tuvalu, and call them the GW8. Then give them the levers to run the global economy. They couldn't do it worse.

Andrew Simms is policy director of nef, the New Economics Foundation, whose report Price of Power: poverty and climate change and the renewable revolution will be published on 21 June