This is the UN's secret plan to save the world

In just the latest example of popular support for science, tens of thousands of people around the world recently marched to advocate for a worldview based on facts, not fiction. They understand that science could actually save the world, because it can help us solve our greatest health and development problems.

Those problems are at the heart of the United Nations Sustainable Development Goals, which the international community agreed to in 2015, with the aim of creating a more prosperous, equitable, and healthy planet by 2030. The 17 SDGs, which include 169 individual targets, constitute an ambitious agenda to address everything from gender equity to sustainable cities and climate change. All told, they provide an inclusive vision of sustainable development for the twenty-first century.

But comprehensiveness can come at the expense of effective action. Few people can actually name all of the SDGs, much less explain how every country can achieve them over the next 13 years. Experts around the world – including all of those who have gathered in New York this week for the UN Ocean Conference – are wrestling with individual targets or goals. And yet integrating these efforts remains a formidable challenge. If our leaders are ever to realize the world envisioned in the SDGs, they will need a roadmap for navigating the complex policymaking terrain.

Scientists are well positioned to provide this roadmap, because they know how to ask the right questions, design experiments, draw evidenced-based conclusions, and apply new information to existing knowledge. Better still, scientists enjoy sharing their findings with others.

The International Council for Science (ICSU) recently brought together 22 scientists from various fields – including oceanography, epidemiology, agronomy, and energy economics – to come up with SDG-specific insights for world leaders to follow. By studying how different goals and targets relate to one another, we developed an independent analytical framework to help leaders prioritize policies within their own countries.

Some SDGs have reinforcing relationships, whereby achieving one will make it easier to achieve others. At the same time, some SDGs may be in conflict, if progress in one area comes at the expense of others. While we have long known that the SDGs interact with one another, the ICSU study is the first time that these interactions have been systematically quantified.

For example, we selected the four SDGs relating to hunger, health, energy, and oceans, and then identified every possible interaction between them and the other goals and targets. We then developed a seven-point scale, ranging from +3 when a given goal or target strongly reinforces another, to -3 when achieving one goal makes it essentially impossible to reach another.

By applying this scale to different SDG relationships, we were able to answer some important questions. For example, we could determine if protecting the oceans will stifle economic growth and urban development in a particular country or region. And we could determine if increasing agricultural production would make it harder to manage natural resources; or if expanding renewable-energy sources would deplete the water supply in already-arid regions.

One exciting discovery we’ve made is that most SDG targets actually do reinforce one another. For example, helping the world’s poorest people shift away from traditional fuels such as firewood, charcoal, and animal dung would go a long way toward reducing deaths and illnesses from air pollution, especially among women and children.

And in cases where different goals do not align, policymakers can make adjustments as needed. For example, we found that increased agricultural production can damage the oceans if it adds to nutrient run-off and other forms of pollution; and this, in turn, could undermine health and long-term food security.

Moreover, our approach had benefits beyond the immediate quantitative findings, because it united scientists from different disciplines around a shared goal. This was no easy task: scientists are critical consumers of information, and they do not always agree with one another. But, owing to the sheer scale of the SDGs, the participants had to hash out their differences, and develop a common language to devise the best way forward. Breaking down disciplinary silos and bringing together different voices is a significant achievement in itself. It can serve as an example for leaders in government, business, and civil society to follow.

So, where do we go from here? Our analytical framework can help countries figure out which SDGs benefit others, and which do not. With it, policymakers can prioritize goals and investments; map existing resources and identify budget gaps; and establish mechanisms for sharing data and information across sectors.

More generally, each country will need to monitor its progress toward each SDG, and revise its approach as needed. This will require diligence from all policymakers. But the potential return on investment, not least a better planet for generations to come, is enormous.

Whether science really will save the world remains to be seen. But one thing we know is that scientists can point us in the right direction.