références en Anglais

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

Planetary Boundaries - summary and implications for policymakers 05.12.2022 Respecting planetary boundaries is essential to preserve the stability of ecosystems and human societies, including in Switzerland. Incorporating this principle into our legal system is consistent with the pursuit of our ...

First complete ‘scientific health check’ shows most global systems beyond stable range in which modern civilisation emerged

For the first time, an international team of scientists is able to provide a detailed outline of planetary resilience by mapping out all nine boundary processes that define a safe operating space for humanity.

This planetary boundaries framework update finds that six of the nine boundaries are transgressed, suggesting that Earth is now well outside of the safe operating space for humanity. Ocean acidification is close to being breached, while aerosol loading regionally exceeds the boundary. Stratospheric ozone levels have slightly recovered. The transgression level has increased for all boundaries earlier identified as overstepped. As primary production drives Earth system biosphere functions, human appropriation of net primary production is proposed as a control variable for functional biosphere integrity. This boundary is also transgressed. Earth system modeling of different levels of the transgression of the climate and land system change boundaries illustrates that these anthropogenic impacts on Earth system must be considered in a systemic context.

Current climate policies will leave more than a fifth of humanity exposed to dangerously hot temperatures by 2100, new research suggests. The paper, published in the journal Nature Sustainability, is entitled "Quantifying the Human Cost of Global Warming."

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Microplastic pollution reduces energy production in a microscopic creature found in freshwater worldwide, new research shows. Paramecium bursaria contain algae that live inside their cells and provide energy by photosynthesis. The results of a NEW STUDY showed a 50% decline in net photosynthesis—a major impact on the algae's ability to produce energy and release oxygen

Freshwater availability is changing worldwide. Here we quantify 34 trends in terrestrial water storage observed by the Gravity Recovery and Climate Experiment (GRACE) satellites during 2002–2016 and categorize their drivers as natural interannual variability, unsustainable groundwater consumption, climate change or combinations thereof. Several of these trends had been lacking thorough investigation and attribution, including massive changes in northwestern China and the Okavango Delta. Others are consistent with climate model predictions. This observation-based assessment of how the world’s water landscape is responding to human impacts and climate variations provides a blueprint for evaluating and predicting emerging threats to water and food security. Analysis of 2002–2016 GRACE satellite observations of terrestrial water storage reveals substantial changes in freshwater resources globally, which are driven by natural and anthropogenic climate variability and human activities.

The deployment of low-tech requires taking into account the human factor and changing design practices.

Recent news articles about a breakthrough in nuclear fusion research heralded the potential for “limitless” energy. Whenever I read that word limitless I wince, because I’ve learned to view it as a subtle instruction to readers to “please stop thinking now.” After decades of false promises to delive

In Europe, a large-scale war could cause the Baltic Sea to freeze over and severely compromise food security – potentially for decades and even centuries to come. An ever-growing body of work has shown that even a local nuclear conflict could usher in a climate catastrophe. As marine scientists, we have considered what this could specifically mean for the world’s oceans. In 1982, a group of scientists including Carl Sagan began to raise the alarm on a climate apocalypse that could follow nuclear war. Using simple computer simulations and historic volcanic eruptions as natural analogues, they showed how smoke that lofted into the stratosphere from urban firestorms could block out the sun for years.