Scientists at climate talks say major changes to the nitrogen cycle cannot be ignored

On a planetary scale, human activities, especially fertiliser application, have more than doubled the amount of reactive nitrogen in circulation on land. This massive alteration of the nitrogen cycle affects climate, food security, energy security, human health and ecosystem health. The long-term consequences of these changes are yet to be fully realised, but the human impact on the nitrogen cycle has so far been largely missed in international environmental assessments.

Nitrogen's role in climate change will be highlighted at an event on 7 December at the COP-15 United Nations Climate Change Conference in Copenhagen. Event organisers will be calling for a new assessment of nitrogen and climate, which will identify innovative nitrogen management strategies for global climate change mitigation and associated co-benefits to society.

Dr Cheryl Palm, the chair of the International Nitrogen Initiative (INI), which is organising the event, said "Nitrogen and climate interactions are not yet adequately included in the Intergovernmental Panel on Climate Change assessment process. There is an urgent need to assess the possibilities of nitrogen management for climate abatement and at the same time increase food security, while minimising environmental and human health impacts."

Dr Palm added, "We believe that in tackling nitrogen new opportunities for climate abatement will be created."

Professor Jan Willem Erisman from the Energy Research Centre of the Netherlands, who will speak at the event said: "An internationally-coordinated global nitrogen assessment is urgently required. A special report on nitrogen and climate is the natural first step."

Kilaparti Ramakrishna, Senior Advisor on Environmental Law and Conventions at UNEP who will give the opening address at the side event said, "The nitrogen cycle is changing faster than that of any other element. In addition, the effects of reactive nitrogen are not limited to a single medium. A single molecule of reactive nitrogen may transition through many forms -- ammonia, nitrogen oxide, nitric acid, nitrate and organic nitrogen -- and may successively lead to a number of environmental, health and social impacts, including contributing to higher levels of ozone in the lower atmosphere. Over the last decade a number of global, regional and national initiatives have identified and addressed the issue of nutrient enrichment to the coastal zone. However, programmes are dispersed and fragmented and there is no single place to go for an overview of available information tools and mechanisms."

Professor Sybil Seitzinger, Executive Director of the International Geosphere-Biosphere Programme said, "We have changed the complexity of the nitrogen cycle profoundly and are unaware of all the implications. In the meantime, policies that affect the nitrogen cycle are often made in isolation of the range of their impacts. This is in part because policies are made in departments/ministries with responsibility for only certain sectors (e.g., air, agriculture, etc.). Furthermore, the scientific community does not yet have an integrated understanding of the multiple impacts and feedbacks of changes in the nitorgen cycle, or the interconnections with other cycles, like carbon. An integrated global nitrogen assessment is needed as soon as possible. This will support the development of tools for policy makers to understand the multiple implications of their decision."

The INI team believes that it is essential to untangle the complexity of the nitrogen and carbon cycle, identify the advantages of nitrogen management for climate abatement and investigates the costs and barriers to be overcome. Such an assessment needs to distinguish between developed areas where there is already an excess of nitrogen and the developing parts of the world where nitrogen management can help increase food security. Improved Nitrogen management will help limit fertilizer use, increase its efficiency and increase carbon sequestration in soils, decrease N2O emissions, while limiting other environmental and human health impacts.

The side event "Options for Including Nitrogen Management in Climate Policy Development" will be held in the US centre (Hall C5) from 6pm local time. The event will be followed by a networking reception supported by the Centre for Ecology & Hydrology (CEH), United Kingdom The organisers of the side event are the INI, CEH, the Ministry of Housing and Spatial Planning and Environment (VROM) of The Netherlands, the United Nations Environment Programme -- Global Partnership on Nutrient Management (UNEP/GPNM), the David and Lucile Packard Foundation, SCOPE, the International Geosphere-Biosphere Programme, COST and the European Science Foundation Nitrogen in Europe Research Networking Programme (NinE-ESF).