A meeting in London this week will show whether science can not only diagnose our environmental crisis but also provide effective solutions.
One of the most significant achievements of science over the past few decades has been to provide convincing evidence that human activity has had a growing and potentially unsustainable impact on virtually every aspect of our planet.
The scientific community now needs to help society find a way out of this situation and on to a sustainable course of social and economic development that is compatible with the planet's natural systems and finite resources.
An opportunity to showcase how this could be done arises next week in the United Kingdom, at the major international conference Planet Under Pressure (PUP), held in London on 2629 March 2012.
The meeting takes place in the run-up to the UN Conference on Sustainable Development (Rio+20) in Rio de Janeiro, Brazil, in June 2012, two decades after Brazil hosted a landmark meeting where treaties were signed on climate, biodiversity and desertification.
The organisers of the London meeting face the challenge of ensuring its recommendations are both concrete and viable if they are to have any lasting impact, not only at Rio+20 but beyond.
The conference must not merely project a litany of warnings of impending catastrophe, voice complaints about the lack of progress in achieving the goals of earlier treaties, or propose new research initiatives without a clear indication of how their results will be used.
Politicians need evidence
The warnings of catastrophe are, of course, still essential, particularly at a time when the minds of most politicians and their electorates in Western nations are focussed on financial issues of more immediate concern.
As economists in these countries struggle to handle vast deficits, they need reminding that the easy credit which, in part, led to the debt crisis, has fuelled a rapacious consumerism that has exacerbated the environmental crisis.
It is no longer sufficient for economic solutions and the political actions they require to be based on fiscal arguments alone.
It is also essential to consider the viability of the natural systems on which all social activity depends as an integral part of any path out of the financial crisis.
The more evidence that scientists can gather to support this, and the better they outline the likely consequences of failure to change current trends, the higher the chances that politicians will adopt policies that are sustainable both economically and environmentally .
But demonstrating the scale and urgency of the problem is not sufficient. It is equally important to ensure that scientists become directly engaged in efforts to draw up and implement solutions at all levels of society.
This means, for example, that the scientific community needs to reorganise itself so it can interact more directly and effectively with policymakers, rather than lecturing them from a distance.
One way that this can be achieved is by ensuring that research priorities are determined by the problems that society needs solving, rather than issues researchers find intellectually stimulating. Increasing the amount of interdisciplinary work required to solve the kinds of complex problems at hand is another option.
Better engagement also means strengthening science advisory mechanisms and local governance. This will ensure that policymakers are adequately informed about the implications of their decisions, for example on steps to mitigate the effects of climate change, and that decisions are guided by scientific evidence. This is already on the agenda for Rio+20.
Finally, it means scientists must link their problem-solving to practical mechanisms that can put solutions into effect for example, by establishing effective technology transfer mechanisms to get novel solutions to the marketplace where they can be disseminated, and by taking measures to fill the gap if the market fails.
Science for society
There is plenty of evidence that, in planning next week's Planet Under Pressure meeting, the organisers have accepted the need for greater engagement of scientists working to meet social needs and priorities. Indeed, they have designed the meeting with this in mind, which some of the organisers describe as unique.
For example, it will involve an unprecedented mix of disciplines debating issues such as the creation of sustainable development goals, and the viability of 'planetary boundaries' as a key concept in tackling sustainability problems.
Also, many of the sessions will focus directly on how best to get science into policy.
Both features of the meeting have already generated a high level of excitement among participating scientists at the prospect of an event that is unique both in its multidisciplinary approach and its commitment to science as the proposer and assessor of solutions to planetary problems.
This enthusiasm seems likely to be reflected in a final declaration that emphasises how science can serve society more effectively, as humanity faces the crisis ahead.
But the proof of the pudding will be in the eating: discussions, detailed analysis and bold declarations of intent alone are not enough. They require commitment and follow-through.
Urgent action is needed to steer the planet towards a more sustainable future. Scientists can draw up the charts of where to go, and the lists of what society must do to get there.
But they also need to help directly, and in practical ways, to ensure that it does. The stakes are too high to fail.