Why do we care about phosphorus? Phosphorus is an essential element for both plant and animal growth and is not replaceable by other elements. In the last 50 years phosphate fertilisers have enhanced crop yields, providing food for billions of people and livestock. World food security is dependent on sufficient access to phosphorus fertilisers for farmers. However, the main source of phosphorus for fertilisers is mining of rocks found only in a few countries, mainly located in politically unstable regions of the world. Many countries, including the UK, rely on imports of phosphate rock for food production. With increasing human population growth and changes in, the worldwide demand for rock phosphate reserves has increased significantly and is projected to continue in the future. Consequently, rock reserves of phosphate are becoming increasingly scarce and the reserves that remain are of poorer quality, often being contaminated with the potentially toxic elements, uranium and cadmium. These concerns have driven fluctuations of fertiliser price and potential political instability. Currently a sixth of the world's farmers cannot afford P fertilisers. At the same time, the mobilisation of phosphorus into the environment has increased fourfold due to greater use of phosphorus fertilisers and uptake and excretion of phosphorus-containing food by the growing human population. The resulting increased phosphorus concentrations in rivers, lakes and coastal waters is causing widespread eutrophication, characterised by toxic algal blooms, oxygen "dead zones" and fish kills. Eutrophication is considered the greatest cause of damage to freshwater ecosystems on the planet. What is needed? Phosphorus security is critical for realising many goals of global society. These include food security and provision of clean water, integrity of ecosystems and fertile soils, maintaining livelihoods, human health and geopolitical security. However, there is little global joined-up thinking about how we can deliver a secure phosphorus future. While the underlying science is key to understanding the nature of the problem and devising technical solutions, our understanding of phosphorus science and technology is only one part of the solution. There is a lack of policy at regional or global scales relating to phosphorus, with phosphorus remaining chronically under-represented within the public consciousness. The United Nations Environment Programme has acknowledged a critical need to identify how we manage phosphorus. What this project delivers. Recognising these global challenges, the 'Our Phosphorus Future' project aims to provide scientific consensus from the global scientific phosphorus community on how to best deliver phosphorus security. The global relevance of this project is demonstrated by the financial support from partners and commitment of UK and worldwide scientists secured already. UK-based scientists will lead an international network of leading phosphorus scientists and stakeholders to co-produce the `Our Phosphorus Future' synthesis report. The report will contain an authoritative and agreed evidence base on phosphorus flows at regional and global scales, examine opportunities for new technologies to enable more sustainable phosphorus use, and evaluate the influence of human behaviour and health on the phosphorus cycle. The report is targeted at scientists and stakeholders, such as national and local governments, water and sewage managers, agricultural advisors, environmental regulators and international policy makers. It will be launched at high profile events and will also be freely-available online. The report will act as a catalyst for interaction between scientists and policy makers to develop global phosphorus management beyond the 2-year timescale of the project. To raise public awareness of phosphorus issues, a global media campaign will accompany the launch of the report.

Humans have massively altered flows of nitrogen on our planet, leading to both benefits for food production and multiple threats to the environment. There are few places on Earth more affected than South Asia, with levels of nitrogen pollution rapidly increasing. The result is a web of interlinked problems, as nitrogen losses from agriculture and from fossil fuel combustion cause air and water pollution. This damages human health, threatens biodiversity of forests and rivers, and leads to coastal and marine pollution that exacerbates the effects of climate change, such as by predisposing reefs to coral bleaching. Altogether, it is clear that nitrogen pollution is something we should be taking very seriously. The amazing thing is that so few people have heard of the problem. Everyone knows about climate change and carbon footprints, but how many people are aware that nitrogen pollution is just as significant? One reason for this is that scientists and policy makers have traditionally specialised. Different experts have focused on different parts of the nitrogen story, and few have the expertise to see how all the issues fit together. This challenge is taken up by a major new research hub established under the UK Global Challenge Research Fund. The "GCRF South Asian Nitrogen Hub" is a partnership that brings together 32 leading research organisations with project engagement partners from the UK and South Asia. All eight countries of the South Asia Co-operative Environment Programme (SACEP) are included. The hub includes research on how to improve nitrogen management in agriculture, saving money on fertilizers and making better use of manure, urine and natural nitrogen fixation processes. It highlights options for more profitable and cleaner farming for India, Pakistan, Bangladesh, Nepal, Afghanistan, Sri Lanka, Bhutan and the Maldives. At the same time, the hub considers how nitrogen pollution could be turned back to fertilizer, for example by capturing nitrogen oxide gas from factories and converting it into nitrate. The fact that all the SACEP countries are included is really important. It means that lessons can be shared on good experiences as well as on whether there are cultural, economic and environmental differences that prevent better management practices from being adopted. It is also important from the perspective of international diplomacy, and provides an example to demonstrate how working together on a common problem is in everyone's interest. It puts the focus on future cooperation for a healthier planet, rather than on the past. The South Asian case provides for some exciting scientific, social, cultural and economic research challenges. The first is simply to get all the researchers talking together and understanding each other. There are dozens of languages in South Asia, matching the challenge met when different research disciplines come together. This is where developing a shared language around nitrogen can really help. There are lots of nitrogen forms ranging from unreactive atmospheric nitrogen (N2), to the air pollutants ammonia (NH3) and nitrogen dioxide (NO2), to nitrate (NO3-) which contaminates watercourses, and nitrous oxide (N2O) which is a greenhouse gas. The impacts of each of these are being studied to provide a better understanding of how they all fit together. The result is an approach that aims to give a much more coherent picture of the nitrogen cycle in South Asia: What is stopping us from taking action, and what can be done about it. One of the big expectations is that the economic value of nitrogen will help. India alone spends around £6 billion per year subsidising fertilizer supply. It means that South Asian governments are strongly motivated to use nitrogen better. At which point research from the South Asian hub can provide guidance on where they might start.

Humans have massively altered flows of nitrogen on our planet, leading to both benefits for food production and multiple threats to the environment. There are few places on Earth more affected than South Asia, with levels of nitrogen pollution rapidly increasing. The result is a web of interlinked problems, as nitrogen losses from agriculture and from fossil fuel combustion cause air and water pollution. This damages human health, threatens biodiversity of forests and rivers, and leads to coastal and marine pollution that exacerbates the effects of climate change, such as by predisposing reefs to coral bleaching. Altogether, it is clear that nitrogen pollution is something we should be taking very seriously. The amazing thing is that so few people have heard of the problem. Everyone knows about climate change and carbon footprints, but how many people are aware that nitrogen pollution is just as significant? One reason for this is that scientists and policy makers have traditionally specialised. Different experts have focused on different parts of the nitrogen story, and few have the expertise to see how all the issues fit together. This challenge is taken up by a major new research hub established under the UK Global Challenge Research Fund. The "GCRF South Asian Nitrogen Hub" is a partnership that brings together 32 leading research organisations with project engagement partners from the UK and South Asia. All eight countries of the South Asia Co-operative Environment Programme (SACEP) are included. The hub includes research on how to improve nitrogen management in agriculture, saving money on fertilizers and making better use of manure, urine and natural nitrogen fixation processes. It highlights options for more profitable and cleaner farming for India, Pakistan, Bangladesh, Nepal, Afghanistan, Sri Lanka, Bhutan and the Maldives. At the same time, the hub considers how nitrogen pollution could be turned back to fertilizer, for example by capturing nitrogen oxide gas from factories and converting it into nitrate. The fact that all the SACEP countries are included is really important. It means that lessons can be shared on good experiences as well as on whether there are cultural, economic and environmental differences that prevent better management practices from being adopted. It is also important from the perspective of international diplomacy, and provides an example to demonstrate how working together on a common problem is in everyone's interest. It puts the focus on future cooperation for a healthier planet, rather than on the past. The South Asian case provides for some exciting scientific, social, cultural and economic research challenges. The first is simply to get all the researchers talking together and understanding each other. There are dozens of languages in South Asia, matching the challenge met when different research disciplines come together. This is where developing a shared language around nitrogen can really help. There are lots of nitrogen forms ranging from unreactive atmospheric nitrogen (N2), to the air pollutants ammonia (NH3) and nitrogen dioxide (NO2), to nitrate (NO3-) which contaminates watercourses, and nitrous oxide (N2O) which is a greenhouse gas. The impacts of each of these are being studied to provide a better understanding of how they all fit together. The result is an approach that aims to give a much more coherent picture of the nitrogen cycle in South Asia: What is stopping us from taking action, and what can be done about it. One of the big expectations is that the economic value of nitrogen will help. India alone spends around £6 billion per year subsidising fertilizer supply. It means that South Asian governments are strongly motivated to use nitrogen better. At which point research from the South Asian hub can provide guidance on where they might start.