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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. We show that following current policies this century would commit to a 45% tipping risk by 2300 (median, 10–90% range: 23–71%), even if temperatures are brought back to below 1.5 °C. We find that tipping risk by 2300 increases with every additional 0.1 °C of overshoot above 1.5 °C and strongly accelerates for peak warming above 2.0 °C. Achieving and maintaining at least net zero greenhouse gas emissions by 2100 is paramount to minimise tipping risk in the long term. Our results underscore that stringent emission reductions in the current decade are critical for planetary stabili
An international research team has established a link between aquatic deoxygenation and the general stability of terrestrial systems, which should lead to the inclusion of deoxygenation as the tenth planetary boundary. This study also proposes to improve tools for monitoring and predicting aquatic systems, and oxygen in particular, by developing numerical models of improved accuracy and setting up a global database of the highest quality.
Anthropogenic emissions drive global-scale warming yet the temperature increase relative to pre-industrial levels is uncertain. Using 300 years of ocean mixed-layer temperature records preserved in sclerosponge carbonate skeletons, we demonstrate that industrial-era warming began in the mid-1860s, more than 80 years earlier than instrumental sea surface temperature records. The Sr/Ca palaeothermometer was calibrated against ‘modern’ (post-1963) highly correlated (R2 = 0.91) instrumental records of global sea surface temperatures, with the pre-industrial defined by nearly constant (<±0.1 °C) temperatures from 1700 to the early 1860s. Increasing ocean and land-air temperatures overlap until the late twentieth century, when the land began warming at nearly twice the rate of the surface oceans. Hotter land temperatures, together with the earlier onset of industrial-era warming, indicate that global warming was already 1.7 ± 0.1 °C above pre-industrial levels by 2020. Our result is 0.5 °C higher than IPCC estim
Existing production destroys more value than it creates due to medical and environmental costs, researchers say
When Rishi Sunak granted 27 new North Sea licences this week, he wasn’t thinking about the survival of the living world, says Guardian columnist George Monbiot
Climate breakdown and crop losses threaten our survival, but the ultra-rich find ever more creative ways to maintain the status quo, says Guardian columnist George Monbiot
Simultaneous harvest failures across major crop-producing regions are a threat to global food security. Concurrent weather extremes driven by a strongly meandering jet stream could trigger such events, but so far this has not been quantified. Specifically, the ability of state-of-the art crop and climate models to adequately reproduce such high impact events is a crucial component for estimating risks to global food security. Here we find an increased likelihood of concurrent low yields during summers featuring meandering jets in observations and models. While climate models accurately simulate atmospheric patterns, associated surface weather anomalies and negative effects on crop responses are mostly underestimated in bias-adjusted simulations. Given the identified model biases, future assessments of regional and concurrent crop losses from meandering jet states remain highly uncertain. Our results suggest that model-blind spots for such high-impact but deeply-uncertain hazards have to be anticipated and acc
A major concern for the world’s ecosystems is the possibility of collapse, where landscapes and the societies they support change abruptly. Accelerating stress levels, increasing frequencies of extreme events and strengthening intersystem connections suggest that conventional modelling approaches based on incremental changes in a single stress may provide poor estimates of the impact of climate and human activities on ecosystems. We conduct xperiments on four models that simulate abrupt changes in the Chilika lagoon fshery, the Easter Island community, forest dieback and lake water quality—representing ecosystems with a range of anthropogenic interactions. Collapses occur sooner under increasing levels of primary stress but additional stresses and/or the inclusion of noise in all four models bring the collapses substantially closer to today by ~38–81%. We discuss the implications for further research and the need for humanity to be vigilant for signs that ecosystems are degrading even more rapidly than previo
An investigation by conservationists has found evidence that deep-seabed mining of rare minerals could cause “extensive and irreversible” damage to the planet.The report, to be published on Monday by the international wildlife charity Fauna & Flora, adds to the growing controversy that surrounds proposals to sweep the ocean floor of rare minerals that include cobalt, manganese and nickel. Mining companies want to exploit these deposits – which are crucial to the alternative energy sector – because land supplies are running low, they say.
By replacing thousands of equations with just one, ecology modelers can more accurately assess how close fragile environments are to a disastrous “tipping point.”
Comprendre les systèmes agroalimentaires. Analyser les dynamiques de transition.
Satisfying the increased demand for food is placing pressure on the world’s water, land and soil resources. Agriculture has its part to play in alleviating these pressures and contributing positively to climate and development goals. Sustainable agricultural practices can lead to direct improvements in the state of land, soil and water, and generate ecosystem benefits as well as reduce emissions from land. Accomplishing all these requires accurate information and a major change in how we manage the resources. It also requires complementing efforts from outside the natural resources management domain to maximize synergies and manage trade-offs.
This paper analyses how recent trends in heat waves impact heat warning systems. We performed a retrospective analysis of the challenges faced by the French heat prevention plan since 2004. We described trends based on the environmental and health data collected each summer by the French heat warning system and prevention plan. Major evolutions of the system were tracked based on the evaluations organized each autumn with the stakeholders of the prevention plan.
In this lecture given at Dartmouth College in the Spring of 1977, Donella Meadows uses two examples of socioecological systems to convey concepts of overshoo...
The WFPHA proposes to lead a discussion about global aid and Global Health Initiatives (GHIs), beginning in these Federation Pages. In this issue (JPHP 31.1), we have invited authors from the Department of Public Health from the Institute of Tropical Medicine Antwerp, Belgium, and from the Federal Ministry of Health, Addis Ababa, Ethiopia to discuss the ‘New dichotomy in health systems’ strengthening and the role of global health initiatives’. Next, the WFPHA will take a very active part in the upcoming Geneva Forum, 19–21 April 2010, entitled Globalization, Crisis & Health Systems: Confronting Regional Perspectives (http://www.ghf10.org/). The problems of GHIs will be the topic of a special session. In it, the organisers will integrate views of researchers, such as the contributors here, along with those of GHIs professionals, and participants from recipient countries.