A group of scientists have warned that human activity is destabilising the Earth system that we depend on, with four of the nine planetary boundaries now being crossed, potentially leading to serious risks and dangers.
The researchers explain that the planetary boundaries concept, first published in 2009, identifies nine global priorities relating to human-induced changes to the environment. These nine processes and systems regulate the stability and resilience of the Earth system – the complex interaction of land, ocean, atmosphere and life – that humans depend on.
In a new study, published in the journal Science, the international team of 18 researchers find that four of these boundaries have now been crossed – climate change, loss of biosphere integrity, land system change and altered biogeochemical cycles. They warn that crossing such boundaries could have serious consequences, both now and in the future, across the world.
Lead author, Professor Will Steffen, from the Stockholm Resilience Centre at Stockholm University and the Australian National University, 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.”
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He added, “We are starting to destabilise our own planetary life support system.”
The study explains that exceeding the planet’s limits is a major cause for concern. For example, eutrophication, when the environment becomes enriched with nutrients, such as from agriculture chemicals, and the continued loss of biodiversity is likely to undermine ecosystem services that human societies depend on.
Continuing to cross the planetary boundaries, which also include stratospheric ozone depletion, ocean acidification, freshwater use, atmospheric aerosol loading, and the introduction of novel entities, could push the Earth system into a new state, the researchers warn.
“In the last four years we have worked closely with policymakers, industry and organisations to explore how the planetary boundaries approach can be used as a framework for sectors of societies to reduce risk while developing sustainably,” said Johan Rockström, co-author of the study and director of the Stockholm Resilience Centre.
“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 and it is hoped a universal climate change agreement can be reached late this year.
Rockström added, “With the right ambition, this could create the conditions for long-term human prosperity within planetary boundaries.”
Photo: NASA Goddard Space Flight Center via Flickr