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I always say that models are not predictions; they are qualitative illustrations of what the future could be. But as the future gets closer to the present, models can start being seen as predictive tools. It is the weather/climate dichotomy, so aptly exploited to confuse matters by politically minded people in the discussion about climate. Right now, we are getting close to the point that we could forecast a collapse in the same way as we can forecast the trajectory of a tropical storm. So, you remember how “The Limits to Growth” generated a long term forecast in 1972. Here it is
The planet is nearing dangerous limits. Yet progress on clean energy shows what’s possible. With political will, cooperation can still avert the worst of the climate crisis
Recent simulations using the Community Earth System Model (CESM) indicate that a tipping event of the Atlantic Meridional Overturning Circulation (AMOC) would cause Europe to cool by several degrees. This AMOC tipping event was found under constant pre-industrial greenhouse gas forcing, while global warming likely limits this AMOC-induced cooling response. Here, we quantify the European temperature responses under different AMOC regimes and climate change scenarios. A strongly reduced AMOC state and intermediate global warming (C, Representative Concentration Pathway 4.5) has a profound cooling effect on Northwestern Europe with more intense cold extremes. The largest temperature responses are found during the winter months and these responses are strongly influenced by the North Atlantic sea-ice extent. Enhanced North Atlantic storm track activity under an AMOC collapse results in substantially larger day-to-day temperature fluctuations. We conclude that the (far) future European temperatures are dependent o
Millions of Americans rely on drinking water systems that have detected these forever chemicals at levels above the now-abandoned limits.
For hundreds of millions of people living in India and Pakistan the early arrival of summer heatwaves has become a terrifying reality that’s testing survivability limits and putting enormous strain on energy supplies, vital crops and livelihoods. Both countries experience heatwaves during the summer months of May and June, but this year’s heatwave season has arrived sooner than usual and is predicted to last longer too. Temperatures are expected to climb to dangerous levels in both countries this week.
Recent projections suggest that large geographical areas will soon experience heat and humidity exceeding limits for human thermoregulation. The survivability limits modeled in that research were based on laboratory studies suggesting that humans cannot effectively thermoregulate in wet bulb temperatures (Twb) above 26 to 31 °C, values considerably lower than the widely publicized theoretical threshold of 35 °C. The newly proposed empirical limits were derived from the Twb corresponding to the core temperature inflection point in participants exposed to stepped increases in air temperature or relative humidity in a climate-controlled chamber. Despite the increasing use of these thermal-step protocols, their validity has not been established. We used a humidity-step protocol to estimate the Twb threshold for core temperature inflection in 12 volunteers.
Published 1972 – The message of this book still holds today: The earth’s interlocking resources – the global system of nature in which we all live – probably cannot support present rates of economic and population growth much beyond the year 2100, if that long, even with advanced technology. In the summer of 1970, an international team of researchers at the Massachusetts Institute of Technology (MIT) began a study of the implications of continued worldwide growth. They examined the five basic factors that determine and, in their interactions, ultimately limit growth on this planet-population increase, agricultural production, nonrenewable resource depletion, industrial output, and pollution generation. The MIT team fed data on these five factors into a global computer model and then tested the behaviour of the model under several sets of assumptions to determine alternative patterns for humankind’s future. The Limits to Growth is the nontechnical report of their findings. The book contains a message of hope a
Donald Trump’s administration is to reconsider the official finding that greenhouse gases are harmful to public health, a move that threatens to rip apart the foundation of the US’s climate laws, amid a stunning barrage of actions to weaken or repeal a host of pollution limits upon power plants, cars and waterways.
💡 Is our obsession with economic growth leading us to collapse? Economist and research Gaya Herrington joins us to discuss why GDP is a flawed metric, how degrowth can lead to a thriving well-being economy, and why businesses must prioritize resilience over efficiency. Tune in for a critical conversation on reshaping our economic future.
There are increasing concerns that continued economic growth in high-income countries might not be environmentally sustainable, socially beneficial, or economically achievable. In this Review, we explore the rapidly advancing field of post-growth research, which has evolved in response to these concerns. The central idea of post-growth is to replace the goal of increasing GDP with the goal of improving human wellbeing within planetary boundaries. Key advances discussed in this Review include: the development of ecological macroeconomic models that test policies for managing without growth; understanding and reducing the growth dependencies that tie social welfare to increasing GDP in the current economy; and characterising the policies and provisioning systems that would allow resource use to be reduced while improving human wellbeing. Despite recent advances in post-growth research, important questions remain, such as the politics of transition, and transformations in the relationship between the Global Nort
The abrupt loss of many species from a system is generally attributed to a breakdown in ecological functioning. As species are sequentially knocked out, the whole community becomes unstable, and it all comes crashing down. Another mechanism that may be at play. My colleagues and I argue that despite the fact life on Earth displays such great variety, many species that live together appear to share remarkably similar thermal limits. That is to say, individuals of different species can tolerate temperatures up to similar points.
This special report on land comes at a time when the scientific evidence is unambiguous: the way we manage our land will directly determine the future of life on Earth. The planetary boundaries framework, highlighted in this report, is a critical scientific tool to understand the complex interdependencies between land, climate, biodiversity and water, among other Earth system components, offering policymakers a focused lens through which to view the potential risks and rewards of different land-use decisions.
The new study, led by researchers at the Global Systems Institute, University of Exeter, associated with the Earth Commission, and Nanjing University, assessed what this would mean for the number of people living outside the “climate niche” in which our species has thrived. It says about 60 million people are already exposed to dangerous heat (average temperature of 29°C or higher). And two billion – 22% of the projected end-of-century population – would be exposed to this at 2.7°C of global warming.
Added complexity allows an economy to grow, even as resource limits are reached. But at some point, the complexity itself becomes a problem.
Human pressures have pushed the Earth system deep into the Anthropocene, threatening its stability, resilience and functioning. The Planetary Boundaries (PB) framework emerged against these threats, setting safe levels to the biophysical systems and processes that, with high likelihood, ensure life-supporting Holocene-like conditions. In this Review, we synthesize PB advancements, detailing its emergence and mainstreaming across scientific disciplines and society. The nine PBs capture the key functions regulating the Earth system. The safe operating space has been transgressed for six of these. PB science is essential to prevent further Earth system risks and has sparked new research on the precision of safe boundaries. Human development within planetary boundaries defines sustainable development, informing advances in social sciences. Each PB translates to a finite budget that the world must operate within, requiring strengthened global governance. The PB framework has been adopted by businesses and informed
Under current emission trajectories, temporarily overshooting the Paris global warming limit of 1.5 °C is a distinct possibility. Permanently exceeding this limit would substantially increase the probability of triggering climate tipping elements. Here, we investigate the tipping risks associated with several policy-relevant future emission scenarios, using a stylised Earth system model of four interconnected climate tipping elements.
Carbon Brief provides an updated analysis of when the world will likely exceed the Paris 1.5C limit
Over the past 50 years, humans have extracted the Earth’s groundwater stocks at a steep rate, largely to fuel global agro-economic development. Given society’s growing reliance on groundwater, we explore ‘peak water limits’ to investigate whether, when and where humanity might reach peak groundwater extraction. Using an integrated global model of the coupled human–Earth system, we simulate groundwater withdrawals across 235 water basins under 900 future scenarios of global change over the twenty-first century. Here we find that global non-renewable groundwater withdrawals exhibit a distinct peak-and-decline signature, comparable to historical observations of other depletable resources (for example, minerals), in nearly all (98%) scenarios, peaking on average at 625 km3 yr−1 around mid-century, followed by a decline through 2100. The peak and decline occur in about one-third (82) of basins, including 21 that may have already peaked, exposing about half (44%) of the global population to groundwater stress. Most
The planetary boundaries concept presents a set of nine planetary boundaries within which humanity can continue to develop and thrive for generations to come
Human activities are threatening to push the Earth system beyond its planetary boundaries, risking catastrophic and irreversible global environmental change. Action is urgently needed, yet well-intentioned policies designed to reduce pressure on a single boundary can lead, through economic linkages, to aggravation of other pressures. In particular, the potential policy spillovers from an increase in the global carbon price onto other critical Earth system processes has received little attention to date. To this end, we explore the global environmental effects of pricing carbon, beyond its effect on carbon emissions. We find that the case for carbon pricing globally becomes even stronger in a multi-boundary world, since it can ameliorate many other planetary pressures. It does however exacerbate certain planetary pressures, largely by stimulating additional biofuel production. When carbon pricing is allied with a biofuel policy, however, it can alleviate all planetary pressures. In the light of nine Earth Syst
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