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Abstract

Total Solar Irradiance (TSI) quantifies the solar energy received by the Earth and therefore is of direct relevance for a possible solar influence on climate change on Earth. We analyse the TSI space measurements from 1991 to 2021, and we derive a regression model that reproduces the measured daily TSI variations with a Root Mean Square Error (RMSE) of 0.17 W/m2. The daily TSI regression model uses the MgII core to wing ratio as a facular brightening proxy and the Photometric Sunspot Index (PSI) as a measure of sunspot darkening. We reconstruct the annual mean TSI backwards to 1700 based on the Sunspot Number (SN), calibrated on the space measurements with an RMSE of 0.086 W/m2. The analysis of the 11 year running mean TSI reconstruction confirms the existence of a 105 year Gleissberg cycle. The TSI level of the current grand minimum is only about 0.15 W/m2 higher than the TSI level of the grand minimum in the beginning of the 18th century.

Keywords: total solar irradiance; sunspot number

cross-posted from: https://lemmy.world/post/15351530

Water-rich Switzerland controls Western Europe’s taps — and wants it to stay that way. Its drought-ridden neighbors are getting nervous.

At the western edge of Lake Geneva, where the mighty Rhône river squeezes through a narrow dam, a blunder of French diplomacy is carved into stone for all to see. 

The inscription, mounted on the walls of an old industrial building, commemorates the 1884 accord between three Swiss cantons that have regulated the water levels of this vast Alpine lake ever since. It does not mention France — even though some 40 percent of the lake is French territory. 

“France, for some reason, wasn’t part of the contract,” said Jérôme Barras as he unlocked a gate below the epigraph to inspect a hydropower plant under the dam he has managed for more than a decade. 

When the agreement was renewed and a new dam was built a century later, Paris still wasn’t interested. 

The French government now regrets that.

…

And France has suddenly realized it can’t control that tap as it battles water shortages, destructive droughts and baking heat.

Abstract

Stratocumulus clouds cover 20% of the low-latitude oceans and are especially prevalent in the subtropics. They cool the Earth by shading large portions of its surface from sunlight. However, as their dynamical scales are too small to be resolvable in global climate models, predictions of their response to greenhouse warming have remained uncertain. Here we report how stratocumulus decks respond to greenhouse warming in large-eddy simulations that explicitly resolve cloud dynamics in a representative subtropical region. In the simulations, stratocumulus decks become unstable and break up into scattered clouds when CO2 levels rise above 1,200 ppm. In addition to the warming from rising CO2 levels, this instability triggers a surface warming of about 8 K globally and 10 K in the subtropics. Once the stratocumulus decks have broken up, they only re-form once CO2 concentrations drop substantially below the level at which the instability first occurred. Climate transitions that arise from this instability may have contributed importantly to hothouse climates and abrupt climate changes in the geological past. Such transitions to a much warmer climate may also occur in the future if CO2 levels continue to rise.

Abstract and Figures

Rapid warming in the Arctic has the potential to release vast reservoirs of carbon into the atmosphere as methane (CH4) resulting in a strong positive climate feedback. This raises the concern that, after a period of near-zero growth in atmospheric CH4 burden from 1999 to 2006, the increase since then may be in part related to increased Arctic emissions. Measurements of CH4 in background air samples provide useful, direct information to determine if Arctic CH4 emissions are increasing. One sensitive first-order indicator for large emission change is the Interpolar Difference, that is the difference in surface atmospheric annual means between polar northern and southern zones (53°–90°), which has varied interannually, but did not increase from 1992 to 2019. The Interpolar Difference has increased moderately during 2020–2022 when the global CH4 burden increased significantly, but not yet to its peak values in the late-1980s. For quantitative assessment of changing Arctic CH4 emissions, the atmospheric measurements must be combined with an atmospheric tracer transport model. Based on multiple studies including some using CH4 isotopes, it is clear that most of the increase in global atmospheric CH4 burden is driven by increased emissions from microbial sources in the tropics, and that Arctic emissions have not increased significantly since the beginning of our measurement record in 1983 through 2022.

Abstract

The Paleocene–Eocene Thermal Maximum (PETM) was a period of geologically-rapid carbon release and global warming ~56 million years ago. Although modelling, outcrop and proxy records suggest volcanic carbon release occurred, it has not yet been possible to identify the PETM trigger, or if multiple reservoirs of carbon were involved. Here we report elevated levels of mercury relative to organic carbon—a proxy for volcanism—directly preceding and within the early PETM from two North Sea sedimentary cores, signifying pulsed volcanism from the North Atlantic Igneous Province likely provided the trigger and subsequently sustained elevated CO2. However, the PETM onset coincides with a mercury low, suggesting at least one other carbon reservoir released significant greenhouse gases in response to initial warming. Our results support the existence of ‘tipping points’ in the Earth system, which can trigger release of additional carbon reservoirs and drive Earth’s climate into a hotter state.

Dr Henri Waisman, at the IDDRI policy research institute in France, said: “Climate change is not a black or white question and every tenth of a degree matters a lot, especially when you look at the socioeconomic impacts. This means it is still useful to continue the fight.”

and while I agree with the sentiment, we really aren't "fighting" are we, quite the opposite. Every thing we're doing is wrong, how do we know this ? CO~2~ppm is still increasing, fossil fuel use increased in 2023, planes are still droning overhead, cars still driving, more roads being built and winded, the Antarctic is being stripped of krill to make pet food etc

Abstract

Perovskite solar cells are a promising technology for emerging photovoltaic applications that require mechanical compliance and high specific power. However, the devices suffer from poor operational stability. Here we develop lightweight, thin (<2.5 μm), flexible and transparent-conductive-oxide-free quasi-two-dimensional perovskite solar cells by incorporating alpha-methylbenzyl ammonium iodide into the photoactive perovskite layer. We fabricate the devices directly on an ultrathin polymer foil coated with an alumina barrier layer to ensure environmental and mechanical stability without compromising weight and flexibility. We demonstrate a champion specific power of 44 W g−1 (average: 41 W g−1), an open-circuit voltage of 1.15 V and a champion efficiency of 20.1% (average: 18.1%). To show scalability, we fabricate a photovoltaic module consisting of 24 interconnected 1 cm2 solar cells and demonstrate energy-autonomous operation of a hybrid solar-powered quadcopter, while constituting only 1/400 of the drone’s weight. Our performance and stability demonstration of ultra-lightweight perovskite solar cells highlight their potential as portable and cost-effective sustainable energy harvesting devices.

Structured Abstract

INTRODUCTION

Anthropogenic carbon dioxide (CO2) emissions have driven an increase in the global atmospheric CO2 concentration from 280 parts per million (ppm) before industrialization to an annual average of 419 ppm in 2022, corresponding to an increase in global mean surface temperature (GMST) of 1.1°C over the same period. If global CO2 emissions continue to rise, atmospheric CO2 could exceed 800 ppm by the year 2100. This begs the question of where our climate is headed. The geologic record is replete with both brief and extended intervals of CO2 concentration higher than today and thus provides opportunities to project the response of the future climate system to increasing CO2. For example, it has been estimated that global surface temperature 50 million years ago (Ma) was ~12°C higher than today, in tandem with atmospheric CO2 concentrations some 500 ppm higher (i.e., more than doubled) than present-day values. Consistent with these estimates, Antarctica and Greenland were free of ice at that time. However, reconstructing these values prior to direct instrumental measurements requires the use of paleoproxies—measurable properties of geological archives that are closely, but only indirectly, related to the parameter in question (e.g., temperature, CO2). To date, at least eight different proxies from both terrestrial and marine archives have been developed and applied to reconstruct paleo-CO2, but their underlying assumptions have been revised over time, and published reconstructions are not always consistent. This uncertainty complicates quantification of the climate responses to the ongoing rise of atmospheric CO2 concentrations.

cross-posted from: https://lemmy.world/post/15159065

Venezuela loses its last glacier as it shrinks down to an ice field

Scientists reclassify Humboldt glacier, also known as La Corona, after it melted faster than expected

Venezuela has lost its last remaining glacier after it shrunk so much that scientists reclassified it as an ice field.

It is thought Venezuela is the first country to have lost all its glaciers in modern times.

The country had been home to six glaciers in the Sierra Nevada de Mérida mountain range, which lies at about 5,000m above sea level. Five of the glaciers had disappeared by 2011, leaving just the Humboldt glacier, also known as La Corona, close to the country’s second highest mountain, Pico Humboldt.

The Humboldt glacier was projected to last at least another decade, but scientists had been unable to monitor the site for a few years due to political turmoil in the country.

Now assessments have found the glacier melted much faster than expected, and had shrunk to an area of less than 2 hectares. As a result, its classification was downgraded from glacier to ice field.

Instead, Cerezo-Mota expects the world to heat by a catastrophic 3C this century, soaring past the internationally agreed 1.5C target and delivering enormous suffering to billions of people. This is her optimistic view, she says.

He mentiond climate change and pollution , well worth a read IMO

“The future is really daunting for people in the Maldives … the climate emergency is an existential threat that overshadows all the other issues.”

over 40 million people have died of air pollution since I became special rapporteur in 2018, yet I just can’t get people to care.

“I can’t get people to bat an eyelash. It’s like there’s something wrong with our brains that we can’t understand just how grave this situation is.”

“I think the right to a healthy environment is actually the foundation that we require to enjoy all other human rights. If we don’t have a living, healthy planet Earth, then all the other rights are just words on paper.”

If we don’t have a living, healthy planet Earth, then all the other rights are just words on paper.

I get his bemusement, just here in Australia, 11,000 die from air pollution from cars annually, another 20,00 are hospitalised annually. The numbers are beyond horrendous and yet, on a scale of 1 to 5 fucks given, it's 0

cross-posted from: https://lemmy.world/post/15144297

Consumers have embraced 'Buy Now, Pay Later' products that allow them to pay for purchases in installments, but it's not clear how many of these loans are out there.

Paywall removed: https://archive.is/9SYHz