The Rio+20 gathering in Brazil last week was little more than a self-indulgent festival of environmental inaction. The idea of holding a summit to mark the 20 years since the world leaders last pledged to save the planet is like holding a lavish anniversary party to celebrate a failed marriage.

To recap, in 1992, at the United Nations Conference on Environment and Development (otherwise known as the Earth Summit), 172 nations and 108 heads of state met in Rio de Janeiro to plot a path to sustainability. From the summit came three non-binding declaratory statements (Rio Declaration on Environment and Development, Agenda 21 and the Forest Principles) and two legally binding treaties (the United Nations Framework Convention on Climate Change and the Convention on Biological Diversity). As their lofty titles suggest, these statements and agreements promised a better environment and a new way of doing business.

By and large, they failed. Greenhouse gas emissions have continued to climb and the condition of the world’s forests, fish stocks and water resources have steadily declined. Not all the news has been negative (of particular note has been the slowdown in the rate of deforestation since the mid-2000s) but the macro trends have been in one direction; backwards. Despite this, thousands of politicians, diplomats and environmentalists clocked up tens of millions of frequent flyer points to “celebrate” the achievements of the past two decades. Imagine what they would have done if we had made progress.

Of course, Rio wasn’t the first anniversary of global failure. In 2002, the great and good converged on Johannesburg to mark the 10th anniversary of the decision to “save the world”. At the time, Australian environmentalists were expressing concern at the apparent lack of action. Their theme was that, despite the promises, “we’ve gone in reverse”.

The more things change, the more things stay the same. Ten years later, the message is essentially the same: very little has been achieved. Things have got so bad that the head of one Australian environment group was quoted as saying that “we are looking for the conference to start a process of developing sustainable development goals”.

So 20 years after we agreed to act, the environment movements’ expectations are now so low that they merely hope to “start a process” to develop goals. The whole farce would be funny if the stakes weren’t so high.

Of course, it’s not just the environment that is on the receiving end of unfulfilled promises. What distinguishes environmental policy from other areas is the size of the gap between the rhetoric and action. Who will ever forget Kevin Rudd’s, “climate change is the greatest moral challenge of our time”? Rudd is not alone though. Ever since the original Earth Summit, governments have made an art form out of talking about sustainability while delivering little.

This is not to say that we should completely abandon multilateralism, or that Australia should walk away from the climate change or biodiversity conventions. What is needed is new ways of achieving change and a refusal to accept vacuous statements from governments as a substitute for action.

The first step in bringing this to fruition needs to come from researchers and environment groups. More resources need to be devoted to testing whether government promises are being fulfilled, and what policies work and don’t work. This is the uns-xy drudgery that many environmentalists steadfastly avoid. But without this information, there can be no momentum for change, no leaver to compel governments to fulfil their promises.

From there, the effort must be directed at ensuring we have policies that work rather than those that merely sound as if they might. The Environment Protection and Biodiversity Conservation Act sounds impressive on paper but does little in practice. Having a policy package called the Clean Energy Future is no good if it doesn’t deliver on its name.

For too long, governments have tamed environmental concerns through words alone. This should be of concern to all taxpayers, not only those who have strong environmental preferences. At present, millions (potentially billions) of dollars are expended annually in Australia on environmental programs that we know don’t do anything, or for which we have no evidence about their cost-effectiveness. If governments are going to expend resources on the environment, they owe it to the taxpayer to ensure they achieve something.

One of the bigger ironies of the Rio+20 debacle is that it included a compilation tally of all of the spending promises of the countries involved. If green groups would start to demand evidence of success rather than support promises to spend we might have got somewhere by now.

*Richard Denniss is executive director of the Australia Institute and Andrew Macintosh is the associate director of the ANU Centre for Climate Law & Policy