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Abstract

Without rapid emission reduction, it is increasingly likely that global temperatures will overshoot 1.5°C before carbon dioxide removal may help reverse warming. Such temperature overshoots affect the future hydrological cycle, with implications for land water availability. However, the hydrological response to such temperature overshoots is not well understood. Here, we investigate regional and seasonal changes of precipitation minus evaporation (P − E) in an ensemble of Earth system model simulations of temperature overshoot. Most climate models broadly show P − E reversibility after overshoot. However, models exhibiting an irreversible shift of the intertropical convergence zone (ITCZ) during the temperature overshoot experience reduced wet-season and enhanced dry-season land water availability in tropical regions, which has long-lasting effects on the amplitude of P − E seasonality after the overshoot, constituting irreversible changes on human timescales. While some regions may experience alleviating seasonal hydrological conditions, others are subject to more intense seasonality. Half a century of CO2-stabilization after the temperature overshoot only halves the legacy effects of the overshoot on land water availability on over 23% of the world population in 12% of the global land area, covering regions of various hydrological regimes. Based on the model ensemble presented here, a strong irreversible shift of the ITCZ after an overshoot is a low-probability but high-impact outcome that would entail long-lasting hydrological changes with consequences for ecosystems and human societies.

Abstract

Aspergillus species cause severe infections in humans, livestock, and plants, and are widespread environmental saprotrophs. With rising global temperatures, climate change is expected to alter the ecological niches and spread of many fungal pathogens. Here, we use global metabarcoding data and Maximum Entropy (MaxEnt) modelling to predict the current and future environmental suitability of three pathogenic Aspergillus species: A. fumigatus, A. flavus, and A. niger. We show that A. fumigatus is more common in temperate climates, while A. flavus and A. niger dominate in warmer regions. Future climate scenarios (SSP126, SSP245, and SSP585) suggest northward shifts in suitability for all three species, particularly under severe warming. We combine the MaxEnt model with spatial models of crop growing areas and human population and show that geographical shift will occur on Aspergillus species along different climate scenarios. A literature review revealed that clinical prevalence of invasive aspergillosis correlates with environmental suitability and we show that different continents have differential expansion or reduction of Aspergillus suitable habitat.

Abstract

Climate extremes are escalating under anthropogenic climate change1. Yet, how this translates into unprecedented cumulative extreme event exposure in a person’s lifetime remains unclear. Here we use climate models, impact models and demographic data to project the number of people experiencing cumulative lifetime exposure to climate extremes above the 99.99th percentile of exposure expected in a pre-industrial climate. We project that the birth cohort fraction facing this unprecedented lifetime exposure to heatwaves, crop failures, river floods, droughts, wildfires and tropical cyclones will at least double from 1960 to 2020 under current mitigation policies aligned with a global warming pathway reaching 2.7 °C above pre-industrial temperatures by 2100. Under a 1.5 °C pathway, 52% of people born in 2020 will experience unprecedented lifetime exposure to heatwaves. If global warming reaches 3.5 °C by 2100, this fraction rises to 92% for heatwaves, 29% for crop failures and 14% for river floods. The chance of facing unprecedented lifetime exposure to heatwaves is substantially larger among population groups characterized by high socioeconomic vulnerabilities. Our results call for deep and sustained greenhouse gas emissions reductions to lower the burden of climate change on current young generations.

Abstract

To calculate the additional copper required for the electrical transition from fossil fuels to electric energy, we first establish a business-as-usual baseline, assuming continued growth in demand driven by global population growth and rising standard of living. We then project the extra copper needs of the electric transition relative to this baseline. The extra copper that cannot be supplied through recycling must be mined, and we determine the annual increase in mining necessary to support the electrical transition. Our analysis shows that, while there is enough discovered copper with resources close to being defined to meet demand for the next 25 years, the rate at which it needs to be mined poses significant challenges. The unavoidable conflict between the copper demands of electrification and achieving equitable living standards for the developing world underscores the importance of resource-realistic policies. Given that the sharp increase in copper demand is primarily driven by batteries, the extra copper needs for electrification can be significantly reduced if the need for electrical storage is minimized. This can be achieved by generating electricity through a mix of nuclear, wind, and photovoltaics; managing power generation with backup electric plants fueled by methane from abundant resources of natural gas; and transitioning to a predominantly hybrid transportation fleet rather than fully electric vehicles.

In light of nationalist trends, disruptions to global food supply chains and efforts to concurrently promote sustainable diets, we assess national capacities to achieve dietary guidelines based on domestic production alone. Over a third of all countries cannot meet self-sufficiency for more than two of the seven essential food groups. Low self-sufficiency and overdependence on a few countries for imports threaten their capability to respond to global shocks, particularly for small states.

Abstract

Gaseous ammonia, while influential in atmospheric processes, is critically underrepresented in atmospheric measurements. This limits our understanding of key climate-relevant processes, such as new particle formation, particularly in remote regions. Here, we present highly sensitive, online observations of gaseous ammonia from a coastal site in Antarctica, which allows us to constrain the mechanism of new particle formation in this region in unprecedented detail. Our observations show that penguin colonies are a large source of ammonia in coastal Antarctica, whereas ammonia originating from the Southern Ocean is, in comparison, negligible. In conjunction with sulfur compounds sourced from oceanic microbiology, ammonia initiates new particle formation and is an important source of cloud condensation nuclei. Dimethylamine, likely originating from penguin guano, also participates in the initial steps of particle formation, effectively boosting particle formation rates up to 10000 times. These findings emphasize the importance of ecosystem processes from penguin/bird colonies and oceanic phytoplankton/bacteria on climate-relevant aerosol processes in coastal Antarctica. This demonstrates an important connection between ecosystem and atmospheric processes that impact the Antarctic climate, which is crucial given the current rate of environmental changes in the region.

Abstract

Over 70,000 excess deaths occurred in Europe during the summer of 2003. The resulting societal awareness led to the design and implementation of adaptation strategies to protect at-risk populations. We aimed to quantify heat-related mortality burden during the summer of 2022, the hottest season on record in Europe. We analyzed the Eurostat mortality database, which includes 45,184,044 counts of death from 823 contiguous regions in 35 European countries, representing the whole population of over 543 million people. We estimated 61,672 (95% confidence interval (CI) = 37,643–86,807) heat-related deaths in Europe between 30 May and 4 September 2022. Italy (18,010 deaths; 95% CI = 13,793–22,225), Spain (11,324; 95% CI = 7,908–14,880) and Germany (8,173; 95% CI = 5,374–11,018) had the highest summer heat-related mortality numbers, while Italy (295 deaths per million, 95% CI = 226–364), Greece (280, 95% CI = 201–355), Spain (237, 95% CI = 166–312) and Portugal (211, 95% CI = 162–255) had the highest heat-related mortality rates. Relative to population, we estimated 56% more heat-related deaths in women than men, with higher rates in men aged 0–64 (+41%) and 65–79 (+14%) years, and in women aged 80+ years (+27%). Our results call for a reevaluation and strengthening of existing heat surveillance platforms, prevention plans and long-term adaptation strategies.

A mysterious, brown foam appeared on a beach an hour south of Adelaide. It was just the beginning of a toxic algal bloom that has now grown to thousands of square kilometres in size, killing precious sea life in its wake. Experts say it could be a sign of things to come.

The blame was placed on an “ongoing marine heatwave” which had seen water temperatures 2.5 degrees Celsius warmer than usual.

I wonder what prciptated the marine heatwave /s

On Kangaroo Island, which reported its first fish kills in March, some beaches were so littered with dead sea life, the smell was overpowering.

Abstract

Microplastics (MPs) and nanoplastics (NPs) are pervasive contaminants in agricultural soils, raising concerns over their environmental fate, food chain infiltration, and potential human health impacts. This review critically examines their primary sources—plastic mulching, biosolids, organic fertilisers, and atmospheric deposition—while distinguishing findings from laboratory, semi-field, and field studies. We assess their effects on soil health, microbial diversity, and crop productivity, emphasising methodological challenges in detecting and quantifying MPs. Plant and soil toxicity studies often use exaggerated MP concentrations (up to 50% by volume), whereas field data indicate much lower yet cumulatively significant levels (typically below 0.1% w/w). This discrepancy reveals the potential for long-term accumulative ecological risks and misrepresentations in many toxicity studies. Accurate toxicity assessments and analytical methodologies are crucial, as exaggerated MP concentrations in studies may misrepresent real-world risks. The review also evaluates plant uptake pathways, exploring bioaccumulation evidence and research discrepancies. In addition, we highlight the role of MPs as carriers of hazardous additives and pollutants, distinguishing their intrinsic effects from those of associated chemicals. A significant gap remains in standardised risk assessments and regulatory frameworks, limiting effective governance despite increasing environmental exposure. We propose future research priorities, including improved detection methods, long-term field studies, environmentally relevant toxicity studies and policy interventions, to mitigate the risks MPs and NPs pose in soil-based food systems. This review highlights the urgent need for coordinated scientific and regulatory efforts to address the growing challenges of agricultural plastic contamination.

Abstract

Following a nuclear war, destruction would extend well beyond the blast zones due to the onset of a nuclear winter that can devastate the biosphere, including agriculture. Understanding the damage magnitude and preparing for the folly of its occurrence are critical given current geopolitical tensions. We developed and applied a framework to simulate global crop production under a nuclear winter using the Cycles agroecosystem model, incorporating ultraviolet (UV)-B radiation effects on plant growth and adaptive selection of crop maturity types (shorter cycle the lower the temperature). Using maize (Zea maize L.) as a sentinel crop, we found that annual maize production could decline from 7% after a small-scale regional nuclear war with 5 Tg soot injection, to 80% after a global nuclear war with 150 Tg soot injection, with recovery taking from 7 to 12 years. UV-B damage would peak 6–8 years post-war and can further decrease annual maize production by 7%. Over the recovery period, adaptive selection of maize maturity types to track changing temperatures could increase production by 10% compared to a no-adaptation strategy. Seed availability may become a critical adaptation bottleneck; this and prior studies might underestimate food production declines. We propose that adaptation must include the development of Agricultural Resilience Kits consisting of region- and climate-specific seed and technology packages designed to buffer against uncertainty while supply chains recover. These kits would be congenial with the transient conditions during the recovery period, and would also be applicable to other catastrophes affecting food production.

Dr. Hansen sold his house and will move to the city in order to be more available for work and advocacy. He handed over care of the animals he raised to a local facility.

Donations can be made to Last Chance Ranch by visiting this link:

https://www.lastchanceranch.org/capital-campaign/

Significance

The productivity of staple crops is a key factor shaping the affordability of food and the amount of land and other resources used in agriculture. We synthesize evidence on how the weather faced by these crops has changed and how these changes have affected productivity. Most cropping regions have experienced both rapid warming and atmospheric drying, with significant negative global yield impacts for three of the five crops. Models can largely reproduce these changes and impacts with two important exceptions—they overstate warming and drying in North America and understate drying in most other temperate regions. These insights can help to guide adaptation efforts and model improvements.

Abstract

Efforts to anticipate and adapt to future climate can benefit from historical experiences. We examine agroclimatic conditions over the past 50 y for five major crops around the world. Most regions experienced rapid warming relative to interannual variability, with 45% of summer and 32% of winter crop area warming by more than two SD (σ). Vapor pressure deficit (VPD), a key driver of plant water stress, also increased in most temperate regions but not in the tropics. Precipitation trends, while important in some locations, were generally below 1σ. Historical climate model simulations show that observed changes in crops’ climate would have been well predicted by models run with historical forcings, with two main surprises: i) models substantially overestimate the amount of warming and drying experienced by summer crops in North America, and ii) models underestimate the increase in VPD in most temperate cropping regions. Linking agroclimatic data to crop productivity, we estimate that climate trends have caused current global yields of wheat, maize, and barley to be 10, 4, and 13% lower than they would have otherwise been. These losses likely exceeded the benefits of CO2 increases over the same period, whereas CO2 benefits likely exceeded climate-related losses for soybean and rice. Aggregate global yield losses are very similar to what models would have predicted, with the two biases above largely offsetting each other. Climate model biases in reproducing VPD trends may partially explain the ineffectiveness of some adaptations predicted by modeling studies, such as farmer shifts to longer maturing varieties.

Abstract

HFC-23 (trifluoromethane) is a potent greenhouse gas released to the atmosphere primarily as a by-product of HCFC-22 (chlorodifluoromethane) synthesis. Since 2020, the Kigali Amendment to the Montreal Protocol has required Parties to destroy their HFC-23 emissions to the extent possible. Here, we present updated HFC-23 emissions estimated from atmospheric observations. Globally, emissions fell to 14.0 ± 0.9 Gg yr-1 in 2023 from their maximum in 2019 of 17.3 ± 0.8 Gg yr-1, but remained five times higher than reported in 2021. Atmospheric observation-based emissions for eastern China, the world’s largest HCFC-22 producer, were also found to be substantially higher than 2020-2022 reported emissions. We estimate that potential HFC-23 sources not directly linked to HCFC-22 production explain only a minor, albeit highly uncertain, fraction of this discrepancy. Our findings suggest that HFC-23 emissions have not been destroyed to the extent reported by the Parties since the implementation of the Kigali Amendment.

Abstract

The pressures humanity has been placing on the environment have put Earth’s stability at risk. The planetary boundaries framework serves as a method to define a ‘safe operating space for humanity’1,2 and has so far been applied mostly to highlight the currently prevailing unsustainable environmental conditions. The ability to evaluate trends over time, however, can help us explore the consequences of alternative policy decisions and identify pathways for living within planetary boundaries3. Here we use the Integrated Model to Assess the Global Environment4 to project control variables for eight out of nine planetary boundaries under alternative scenarios to 2050, both with and without strong environmental policy measures. The results show that, with current trends and policies, the situation is projected to worsen to 2050 for all planetary boundaries, except for ozone depletion. Targeted interventions, such as implementing the Paris climate agreement, a shift to a healthier diet, improved food, and water- and nutrient-use efficiency, can effectively reduce the degree of transgression of the planetary boundaries, steering humanity towards a more sustainable trajectory (that is, if they can be implemented based on social and institutional feasibility considerations). However, even in this scenario, several planetary boundaries, including climate change, biogeochemical flows and biodiversity, will remain transgressed in 2050, partly as result of inertia. This means that more-effective policy measures will be needed to ensure we are living well within the planetary boundaries.