Humanity has dangerously overstepped three of the planet’s nine key natural thresholds, and are on track to cross the remaining six in coming decades, according to a new warning from an international team of scientists.
Taken together, the potential threats make it “too late to be a pessimist,” according to one of the researchers.
The three areas in which people have passed the limits of safe operating space are climate change, biodiversity loss and the nitrogen portion of the nitrogen/phosphorus inputs to the biosphere and ocean. The world is also approaching the safety limits for land system change, ocean acidification, global freshwater use and the phosphorus portion of the nitrogen/phosphorus inputs to the biosphere and ocean.
Two other thresholds — chemical pollution and atmospheric aerosol loading — have yet to be quantified by the research team.
“Until now, the scientific community has not attempted to determine the limits of the Earth system’s stability in so many dimensions and make a proposal such as this,” said Sander van der Leeuw, director of the School of Human Evolution and Social Change at Arizona State University and a co-author of the study published this week in the journal Nature. “On a finite planet, at some point, we will tip the vital resources we rely upon into irreversible decline if our consumption is not balanced with regenerative and sustainable activity.”
The groundbreaking study, undertaken by 29 European, Australian and US, not only identifies the critical tipping points for nine vital planetary systems but examines how stresses in one system affect other systems as well. The research aims to answer the question: ‘How much pressure can the Earth system take before it begins to crash?”
Scientists have dubbed our current era the Anthropocene, the first in which the actions of 6-plus billion humans have become the main driver of global environmental change.
In their Nature article, “A safe operating space for humanity,” the international research team proposes a limit for each boundary that would maintain the conditions for a livable world. For biodiversity, for example, the limit is less than 10 extinctions per million species per year. The extinction rate today is 100 species per million per year, compared to the pre-industrial value of 0.1 to 1 species.
While that approach doesn’t offer a complete roadmap for sustainable development, it does provide an important element by identifying critical planetary boundaries, the researchers say.
“We expect the debate on global warming to shift as a result, because it is not only greenhouse gas emissions that threaten our planet’s equilibrium,” said van der Leeuw. “There are many other systems and they all interact, so that crossing one boundary may make others even more destabilized.”
The team represents the threats to each natural system using an illustration of a polygon made up of nine wedges (one for each vital system); the green inner core of the polygon indicates the safe operating space for each system, while overlaying red wedges show how far humanity has pushed each system.
“We must make these complicated ideas clear in such a way that they can be widely applied,” said van der Leeuw. “The threats are so enormous that it is too late to be a pessimist.”
“Human pressure on the Earth system has reached a scale where abrupt global environmental change can no longer be excluded,” said lead author Johan Rockström, director of the Stockholm Resilience Centre at Stockholm University. “To continue to live and operate safely, humanity has to stay away from critical ‘hard-wired’ thresholds in Earth’s environment, and respect the nature of the planet’s climatic, geophysical, atmospheric and ecological processes. Transgressing planetary boundaries may be devastating for humanity, but if we respect them we have a bright future for centuries ahead.”
Co-author Diana Liverman, a professor of geography and development at the University of Arizona, added, “Our attempt to identify planetary boundaries that, if crossed, could have serious environmental and social consequences has a special resonance in the southwest where pressures on biodiversity, land use, and water are likely to intersect with climate change to create tremendous challenges for landscapes and livelihoods.”
Liverman is currently attending an international climate conference at Oxford, where participants are discussing the implications for humans and Earth ecosystems of a 4-degree Centigrade global temperature rise.
In addition to Liverman, Rockström and van der Leeuw, the group of authors includes Hans Joachim Schellnhuber, Will Steffen, Katherine Richardson, Jonathan Foley and Nobel laureate Paul Crutzen.
2 Comments
Pierre Champagne
It seems to increasingly become the consensus that the planet is reaching its limits. Most metals will be in short supply in the coming decades based on the latest USGS statistics.
Perhaps the only way to avert disaster is the aggressive environmental strategy involving green growth, degrowth, and depopulation proposed in the book The Depletion Wall. It would deliver a greening of the economy, degrowth in consumption, and could maintain or increase per capita incomes.
Nihal Sinnadurai
Energy must grow, Environmental pollution must decrease – Electronics has solutions
Today the proliferation of electronics products, their manufacture and disposal, may be viewed in two ways: – as posing additional threats to the fragile balance of the Earth’s eco systems – and beneficially as providing solutions to many of our current and future environmental and energy related problems.
The environmental threats from electronics can be reduced significantly or eliminated through the conscious environmentally-responsible choice of materials, technologies, design, manufacture, distribution, usage, and end-of-life disposal – which is exactly what the responsible electronics technology community is doing today. In a similar way, the application of electrical and electronics technologies and devices for power generation, electric and hybrid automobiles and solid-state lighting can significantly contribute in a positive way to reducing mankind’s carbon footprint and improve our environment. Thus, consciously and demonstrably, electronics technologies, devices and applications are making major contributions through
• the removal of toxins and pollutants
• innovative materials enabling reduction in use of polluting materials
• new electronics energy sources destined to become the long-term major sustainable sources
• solid state lighting which is decreasing the consumption of energy whilst providing improved illumination
• nano-electronics products which increasingly enable more efficient use of energy in many walks of life
If our populace and political leaders have the vision to adopt the policy that we are custodians of this earth – for the future of life on earth, rather than being avaricious consumers who regard it as someone else’s problem – then we may take steps to reverse the negative environmental impacts. Regrettably, the so-called green campaign groups, who, whilst they acknowledge the environmental hazards and global warming, have their heads in the clouds when proposing solutions. They appear to have no comprehension of human behaviour nor do they comprehend the needs of innovation and progress and continuing exploration. Getting that balance right, and doing it now, will enable mankind to continue to be the adventurous spirit that has made us explorers and innovators without boundaries. We must have growth in energy (all varieties of sustainable, including nuclear), we must enable innovation, we must enable travel (not to have cheap drunken binges, but to explore, learn and wonder at this marvellous blue yet fragile planet in which we live, and also to sustain the ability to go beyond its boundaries).
Electronics technologies and products provide major opportunities for present and future long-term sustainable provision and use of energy. A mixed bag of sustainable energy sources is forecast to grow through to 2030, the hole in provision being met predominantly by nuclear up to that time. Then, wind is expected to reach the same level of provision as nuclear and both will maintain those levels through to 2100 (during which time the long held promise of even cleaner fusion may emerge, but is not considered in the forecast). Meanwhile energy provision by Photo-Voltaics (PV) will progressively improve through second and third generation technologies to high efficiency and low cost and are forecast eventually to dominate energy provision by 2040. Electronics and electrical contribution to efficient and reduced consumption is provided both directly and by improving the efficiency of products. Already, we have seen a major city such as San Jose committing to clean lighting using LEDs, anticipating a whole-life cost benefit. In Europe the EC has invested in R&D to develop smart power trains for automotives. And the hybrid and electric cars have become generally available.
In sustaining human endeavour, the haves in the so-called developed world must not pull away the ladder from the have-nots of the developing world. The innovators of each world are the clever minority, whilst the majority, who are the market for the innovators, are also the consumers of products and energy. Creativity will come increasingly from the developing world and must be encouraged and sustained. This is already happening – exemplified by the innovations such as Building Integrated Photo-Voltaics (BIPV) to enable energy sources to be deployed in cities. In Hong Kong, the headquarters of the Electrical and Mechanical Services Department has 2,300 of PV modules on the roof top which covers an area of 7,900m2. The PV modules are made up of high efficiency mono-crystalline silicon cells, which face south and are tilted to maximize the received solar radiation. This is a major benefit compared with some 25,000 m2 of farm land in Arizona required to generate the same power output. China is also leading the way in building electric cars (the “Coda”) and hybrids (F3DM), using its late-starter advantage in not having to unlearn more than one hundred years of internal combustion engines. The challenge for electric vehicles that remains is to develop lightweight high energy battery technologies.
It is evident that electronics products are leading the “green” wave (no lead, less power, non-brominated flame retardants, increased recycling) and have introduced responsible end-to-end product design (full life cycle). Photovoltaics, which are most effective in the areas of high solar insulation, hold significant promise for clean, safe energy. Solid state lighting will have major impact on home and business lighting within five years. Overall improved electronics, either by their energy savings and environmental friendliness or by clean, efficient power and light generation, are paving the way for a better future. Thus, consciously and demonstrably, electronics technologies, devices and applications are making major contributions through the removal of toxins and pollutants, the reductions in energy consumption, the new lighting systems and the increasing tapping into solar energy and thereby delivering power to the community.
Nihal Sinnadurai
Fellow Inst. Physics,
IEEE Fellow & Distinguished Lecturer
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