Articles

Significance: “Widespread human impacts on the environment are expected to harm human health, which may in turn alter our interactions with the environment. However, evidence for impacts of environmental changes on health, and for feedbacks between environmental change and health, remains locally specific and context dependent. Using a large, geospatial dataset encompassing the Brazilian Amazon rainforest across 13 y, we identify strong evidence for a feedback between deforestation and malaria: Deforestation significantly increases malaria transmission, while high malaria burden simultaneously reduces forest clearing. Our results put into broader context the contradictory effects of deforestation on malaria found in earlier studies and provide evidence useful to land use policy and public health interventions that provide win–win solutions for conservation and health.”

Abstract: “The health co-benefits of CO₂ mitigation can provide a strong incentive for climate policy through reductions in air pollutant emissions that occur when targeting shared sources. However, reducing air pollutant emissions may also have an important co-harm, as the aerosols they form produce net cooling overall. Nevertheless, aerosol impacts have not been fully incorporated into cost-benefit modeling that estimates how much the world should optimally mitigate. Here we find that when both co-benefits and co-harms are taken fully into account, optimal climate policy results in immediate net benefits globally, overturning previous findings from cost-benefit models that omit these effects. The global health benefits from climate policy could reach trillions of dollars annually, but will importantly depend on the air quality policies that nations adopt independently of climate change. Depending on how society values better health, economically optimal levels of mitigation may be consistent with a target of 2 °C or lower.”

“Awareness of climate tipping points has grown in policy circles in recent years in no small part thanks to the work of climate scientist Tim Lenton, who serves as the director of the Global Systems Institute at Britain’s University of Exeter. In 2008 Lenton was the lead author of an influential Proceedings of the National Academy of Sciences (PNAS) paper that identified nine tipping points and ranked them by their near-term likelihood of occurring. These included: Arctic Sea-Ice; the Greenland Ice Sheet; the West Antarctic Ice Sheet; the Atlantic Thermohaline Circulation; the El Niño–Southern Oscillation (ENSO); the Indian Summer Monsoon; the Sahara/Sahel and West African Monsoon; the Amazon Rainforest; and the Boreal Forest. Lenton and his colleagues have since added tropical coral reefs and the East Antarctic Ice Sheet to the list.”

Abstract: “The term “tipping point” commonly refers to a critical threshold at which a tiny perturbation can qualitatively alter the state or development of a system. Here we introduce the term “tipping element” to describe large-scale components of the Earth system that may pass a tipping point. We critically evaluate potential policy-relevant tipping elements in the climate system under anthropogenic forcing, drawing on the pertinent literature and a recent international workshop to compile a short list, and we assess where their tipping points lie. An expert elicitation is used to help rank their sensitivity to global warming and the uncertainty about the underlying physical mechanisms. Then we explain how, in principle, early warning systems could be established to detect the proximity of some tipping points.”

Indonesia says Cop26 zero-deforestation pledge it signed ‘unfair’

Environment minister of country home to world’s third-biggest rainforest says deforestation pledge must not halt development (Guardian Article)

UK will ‘pause’ publication of data showing biodiversity in decline

Next year will see an important meeting to agree global biodiversity targets, but the UK says it won’t be publishing key data on wildlife and habitats (NewScientist Article)

‘A tipping point’: how poor forestry fuels floods and fires in western Canada

Clearcutting worsens heavy rain events but selective logging is needed to limit wildfire threat, experts say (Guardian article)