Four of nine planetary boundaries now crossed
Four of nine planetary boundaries have now been crossed as a result of human activity, says an international team of 18 researchers, also from University of Copenhagen. The four are: climate change, loss of biosphere integrity, land-system change, altered biogeochemical cycles (phosphorus and nitrogen).
The scientists say that two of these, climate change and biosphere integrity, are “core boundaries”. Significantly altering either of these “core boundaries” would “drive the Earth System into a new state”.
The study is published in Science and the team will present their findings in seven seminars at the World Economic Forum in Davos (21-24 January).
Lead author, Professor Will Steffen from the Stockholm Resilience Centre, at Stockholm University and the Australian National University, Canberra, said: “Transgressing a boundary increases the risk that human activities could inadvertently drive the Earth System into a much less hospitable state, damaging efforts to reduce poverty and leading to a deterioration of human wellbeing in many parts of the world, including wealthy countries. In this new analysis we have improved our quantification of where these risks lie.”
The planetary boundaries concept, first published in 2009, identifies nine global priorities relating to human-induced changes to the environment. The science shows that these nine processes and systems regulate the stability and resilience of the Earth System – the interactions of land, ocean, atmosphere and life that together provide conditions upon which our societies depend.
Managing these priorities at safe global levels will enable world development within a safe operating space on Earth, say the researchers. The new research builds on a large number of scientific publications critically assessing and improving the planetary boundaries research since its original publication. It confirms the original set of boundaries and provides updated analysis and quantification for several of them, including phosphorus and nitrogen cycles, land-system change, freshwater use and biosphere integrity. Biosphere integrity relates to the scale and impact of humans on ecosystems.
As human activity pushes the Earth System beyond planetary boundaries and into zones of increasing risk, marine ecosystems may change dramatically as a result of ocean acidification and eutrophication, or temperatures may rise so high as to pose significant threats to agricultural production, infrastructure and human health. The paper reports that continuing degradation of biosphere integrity will likely further erode the provision of ecosystem services on which human societies depend.
“Past a certain threshold, curbing greenhouse gas emissions, biodiversity loss, or land-use change, for example, may not reverse or even slow the trends of Earth System degradation, with potentially catastrophic consequences,” said Professor Steffen.
“Planetary Boundaries do not dictate how human societies should develop but they can aid decision-makers by defining a safe operating space for humanity,” says co-author Katherine Richardson from the Center for Macroecology, Evolution and Climate, University of Copenhagen.
This week, co-author Professor Johan Rockström, director of the Stockholm Resilience Centre, will present the new findings at the World Economic Forum. “In the last four years we have worked closely with policymakers, industry and organisations like WWF to explore how the planetary boundaries approach can be used as a framework for sectors of societies to reduce risk while developing sustainably.”
“It is obvious that different societies over time have contributed very differently to the current state of the earth. The world has a tremendous opportunity this year to address global risks, and do it more equitably. In September, nations will agree the UN’s Sustainable Development Goals. With the right ambition, this could create the conditions for long-term human prosperity within planetary boundaries,” he said.
Eight of the nine planetary boundaries have been quantified (see table at end). With climate change, for example, the team argue that carbon dioxide levels should not cross 350 parts per million (ppm) in the atmosphere. “This boundary is consistent with a stabilisation of global temperatures at about 1.5 degrees Celsius above pre-industrial levels,” said Professor Rockström.
Atmospheric concentrations of carbon dioxide are currently about 399ppm (December 2014) and growing at about 3ppm per year.
In December 2015, nations will meet in Paris to negotiate an international emissions agreement to attempt to stabilise temperatures at 2 degrees Celsius above pre-industrial levels.
“Our analysis suggests that, even if successful, reaching this target contains significant risks for societies everywhere. Two degrees must therefore be seen not only as a necessary but also a minimum global climate target,” said Professor Rockström.
The planetary boundaries research coincides with a second analysis, also led by Professor Will Steffen, that charts “The Great Acceleration” in human activity since 1950. The paper, “The trajectory of the Anthropocene: the Great Acceleration”, focuses on a planetary “dashboard” of 24 social, economic and environmental indicators. The assessment concludes that the global economic system is the prime driver of change of key components of the Earth System, supporting the need for a precautionary approach to transgressing planetary boundaries.
Professor Katherine Richardson
Center for Macroecology, Evolution and Climate
and Sustainability Science Center
University of Copenhagen
Phone: +45 28754285
Communications Officer Elisabeth Wulffeld
University of Copenhagen
Phone: +45 21179140
Stockholm Resilience Centre, Stockholm University, Sweden
Fenner School of Environment and Society, The Australian National University, Canberra, Australia
Center for Macroecology, Evolution and Climate, Natural History Museum, University of Copenhagen, Denmark
McGill University, Ste. Anne de Bellevue, Québec, Canada
Centre for Studies in Complexity, Stellenbosch University, South Africa
University of Wisconsin, Madison WI USA
Wageningen University Alterra, Wageningen, The Netherlands
Stockholm University, Sweden
Beijer Institute of Ecological Economics, Stockholm, Sweden
Potsdam Institute of Climate Impact Research (PIK), Potsdam, Germany
University College, London, UK
Stockholm Environment Institute, Stockholm, Sweden
Scripps Institution of Oceanography, La Jolla CA USA
Council for Scientific and Industrial Research (CSIR), Stellenbosch, South Africa
Royal Institute of Technology (KTH), Stockholm, Sweden
Nine planetary boundaries
- Climate change
- Change in biosphere integrity (biodiversity loss and species extinction)
- Stratospheric ozone depletion
- Ocean acidification
- Biogeochemical flows (phosphorus and nitrogen cycles)
- Land-system change (for example deforestation)
- Freshwater use
- Atmospheric aerosol loading (microscopic particles in the atmosphere that affect climate and living organisms)
- Introduction of novel entities (e.g. organic pollutants, radioactive materials, nanomaterials, and micro-plastics).
- The concept of planetary boundaries has been updated with new assessments and quantifications.
- Climate change and biosphere integrity identified as core planetary boundaries.
- Four boundaries are assessed to have been crossed, placing humanity in a danger zone: climate change, loss of biosphere integrity, land-system change, altered biogeochemical cycles (fertiliser use - phosphorus and nitrogen).
- Crossing boundaries raises the risks to current and future societies of destabilising the Earth System – the complex interactions of land, ocean, atmosphere, ice sheets, life and people.
- Internationally agreed upper climate limit of 2 degrees lies beyond the climate change boundary: which makes 2 degrees a risky target for humanity, and therefore an absolute minimum target for the global climate negotiations.