Collapse

ABSTRACT

Ocean acidification has been identified in the Planetary Boundary Framework as a planetary process approaching a boundary that could lead to unacceptable environmental change. Using revised estimates of pre-industrial aragonite saturation state, state-of-the-art data-model products, including uncertainties and assessing impact on ecological indicators, we improve upon the ocean acidification planetary boundary assessment and demonstrate that by 2020, the average global ocean conditions had already crossed into the uncertainty range of the ocean acidification boundary. This analysis was further extended to the subsurface ocean, revealing that up to 60% of the global subsurface ocean (down to 200 m) had crossed that boundary, compared to over 40% of the global surface ocean. These changes result in significant declines in suitable habitats for important calcifying species, including 43% reduction in habitat for tropical and subtropical coral reefs, up to 61% for polar pteropods, and 13% for coastal bivalves. By including these additional considerations, we suggest a revised boundary of 10% reduction from pre-industrial conditions more adequately prevents risk to marine ecosystems and their services; a benchmark which was surpassed by year 2000 across the entire surface ocean.

Highlights

Honeybee temporal removal on a small island increased nectar and pollen availability

Without honeybees, wild bees increased activity and changed hourly patterns

Without honeybees, wild bees increased nectar intake and optimized search time

Wild bee abundance declined ∼80% in 4 years, supporting trophic competition

Summary

High densities of managed honeybees (Apis mellifera) can threaten wild bees through exploitative competition, thus leading to population declines of the latter. Although reviews have outlined key steps to demonstrate these impacts—measuring resource overlap, changes in wild bee behavior, and population trends—studies that comprehensively address these aspects are virtually absent. We were granted access to the entire protected island of Giannutri (2.6 km2) and to the apiary (18 hives) located there during the early phase of coexistence between honeybees and wild bees. Using the island as an open-air laboratory, we experimentally manipulated honeybee pressure by closing the hives on selected days during the peak of the wild bee foraging period. In the plants most visited by pollinators, even short-term honeybee removals (11 h per day) increased nectar volume (∼60%) and pollen availability (∼30%). In the absence of honeybees, target wild bees (Anthophora dispar and Bombus terrestris) became dominant in the insect-plant visitation network, and the potential apparent competition significantly decreased. Accordingly, both species intensified their foraging activity and increased nectar suction time, a recognized proxy for the quantity of probed nectar, and Bombus terrestris also shortened the time of pollen searching. Transect monitoring revealed an alarming ∼80% decline in both species over 4 years, consistent with honeybee monopolization of floral resources, thus reducing availability for wild pollinators and altering their foraging budget. These findings underscore the risks of introducing high densities of honeybees into protected areas and emphasize the need for rigorous preventive ecological assessments.

Abstract

In this work, the electroreduction of carbon dioxide (CO2) to oxalate is enabled by incorporating trace metallic lead (Pb) on carbon-based supports (CBS) with polymer overlayers. These composite materials serve as an efficient electrocatalytic system for the facile conversion and storage of CO2, a pernicious atmospheric pollutant. Results from controlled potential electrolysis experiments indicate that 1) trace metallic Pb on the ppb scale is active toward the reductive coupling of CO2 to oxalate at comparable Faradaic efficiencies to bulk metallic Pb and 2) polymer encapsulation of this trace metallic Pb leads to promotion of CO2 reduction (CO2R) selectively to metal oxalates over other products such as CO. Importantly, metal oxalates are important alternative cementitious materials and precursors for other materials’ synthesis applications. The solid products undergo rigorous spectroscopic characterization, including 13CO2 labeling experiments, to ensure the metal oxalates are in fact produced from CO2R. These findings serve as a model for leveraging microenvironment effects to enhance activity and selectivity for CO2R using trace-metal catalysts for carbon utilization and storage technologies.

Years of underfunding caused the educational institutions to recruit a lot of foreign students. Now with the federal government slashing those visas for foreign students, and with new policy that limits post graduate immigration options, post secondary institutions are faced with closing and gutting programs, laying off staff and eyeing a billion dollar loss next year.

A new study found that ocean acidification’s “boundary” was reached about five years ago. 60% of global waters have breached the limits for acidification.

A planetary boundary is the limit of the natural system to rebound without failing.

The study says the impacts are worse than previously thought.

cross-posted from: https://lemmy.world/post/31033182

On the Berkeley data, the PLF10 model estimates the final value at 1.41 ± 0.10 °C and final warming rate at 0.38 ± 0.14 °C/decade (2σ confidence intervals).

If the globe continues to warm at that rate, then we’ll cross the 1.5 °C limit of the Paris Climate Accord before the year 2030.

2024 was the warmest year since records began being kept 175 years ago. According to the World Meteorological Organization’s latest State of the Global Climate report:

• Each of the past ten years set a new global temperature record.

• Each of the past eight years set a new record for ocean heat content.

• The 18 lowest Arctic sea-ice extents on record were all in the past 18 years.

• The three lowest Antarctic ice extents were in the past three years.

• The largest three-year loss of glacier mass on record occurred in the past three years.

• The rate of sea level rise has doubled since satellite measurements began.[1]

There is no room for doubt: Earth is getting hotter. The question now is how hot will it get?

ABSTRACT

The photic zones of the oceans—where sunlight and moonlight drive ecological interactions—are one of the most productive habitats on the planet and fundamental to the maintenance of healthy global biogeochemical cycles. Ocean darkening occurs when changes in the optical properties of the oceans reduce the depth to which sufficient light penetrates to facilitate biological processes guided by sunlight and moonlight. We analysed a 9 km resolution annual time series of MODIS Aqua's diffuse attenuation coefficient of light at 490 nm [Kd(490)] to quantify whether the oceans have darkened over the last 20 years and the impact of this on the depth of photic zones around the world. Kd(490) increased across 75,341,181 km2 (21%) of the global ocean between 2003 and 2022, resulting in photic zone depths reducing by more than 50 m across 32,449,129 km2 (9%) by area. The depth of the photic zone has reduced by more than 10% across 32,446,942 km2 (9%) of the global ocean. Our analysis indicates that ocean darkening is not restricted to coastal regions, but affects large swathes of the open ocean. A combination of nutrient, organic material and sediment loading near the coasts and changes in global ocean circulation are probable causes of increases in primary and secondary productivity that have reduced light penetration into surface waters. The implications of ocean darkening for marine ecology and the ecosystem services provided by the surface oceans are currently unknown but likely to be severe.

Abstract

Drought is one of the most common and complex natural hazards affecting the environment, economies and populations globally1,2,3,4. However, there are significant uncertainties in global drought trends4,5,6, and a limited understanding of the extent to which a key driver, atmospheric evaporative demand (AED), impacts the recent evolution of the magnitude, frequency, duration and areal extent of droughts. Here, by developing an ensemble of high-resolution global drought datasets for 1901–2022, we find an increasing trend in drought severity worldwide. Our findings suggest that AED has increased drought severity by an average of 40% globally. Not only are typically dry regions becoming drier but also wet areas are experiencing drying trends. During the past 5 years (2018–2022), the areas in drought have expanded by 74% on average compared with 1981–2017, with AED contributing to 58% of this increase. The year 2022 was record-breaking, with 30% of the global land area affected by moderate and extreme droughts, 42% of which was attributed to increased AED. Our findings indicate that AED has an increasingly important role in driving severe droughts and that this tendency will likely continue under future warming scenarios.

Have noticed a ton more houses for sale in my city, about double of last year. Prices have declined and houses are staying on the market longer. I think people thought interest rates were finally going to go down but with the fed keeping them at their current levels there’s a lot of owners trying to get out of the market while it’s still relatively up. I suspect within another year the bubble is going to burst.

new point in history has been reached, entomologists say, as climate-led species’ collapse moves up the food chain even in supposedly protected regions free of pesticides

Its collapse was in many ways a good thing for a lot of people.

Looking around me, as it will be again

cross-posted from: https://lemm.ee/post/65824884

Hey everyone

We’re really sorry to say this, but lemm.ee will be shutting down on June 30, 2025.

What you need to know

As of now:

• New user registrations are disabled
• Creating new communities is disabled

What you should do:

• You can export your settings at https://lemm.ee/settings to take them with you to another instance.
• If you're moving to another instance, consider adding a note to your lemm.ee profile with your new username. Your old profile will still be visible from other instances even after we go offline.
• Alternatively, if you want to delete your lemm.ee profile, now is the best time to do it, so the deletion can federate out before we go offline.
• If you're one of the folks supporting us with a recurring donation, please remember to cancel it (Ko-Fi donations should have been cancelled automatically already). Our leftover funds are already enough to cover our bills for next month, so we can keep things running without any more support.

Because of how Lemmy is built, everything posted on lemm.ee will still be accessible from other instances, even after we go offline.

Why this is happening

The key reason is that we just don’t have enough people on the admin team to keep the place running. Most of the admin team has stepped down, mostly due to burnout, and finding replacements hasn’t worked out.

The sad reality is that while there are a lot of great people on Lemmy, there are also some who use the platform to attack others, stir up conflict, or actively try to undermine the project. Admins are volunteers who deal with the latter group on a constant basis, this takes a mental toll. Please understand why our admins chose to step down, and be kind to the admins on whatever instance you decide to join.

We know this sucks. We're genuinely sorry it’s ending like this. Thank you to everyone who spent time here and helped make it better.

– lemm.ee team

Won't be long now.

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.