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#albedo

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Rising sea levels, melting #glaciers, heatwaves at sea – 2023 set a number of alarming new records.

The global mean #temperature also rose to nearly 1.5°C above the preindustrial level, another record.

Seeking to identify the causes of this sudden rise has proven a challenge for researchers.

The potential cause is a decrease in Earth's #albedo due to changes in cloud patterns, corresponding to another positive feedback loop amplifying the warming.

#climate
astrobiology.com/2024/12/rapid

Astrobiology · Rapid Surge In Global Warming Mainly Due To Reduced Planetary Albedo - AstrobiologyRising sea levels, melting glaciers, heatwaves at sea – 2023 set a number of alarming new records.

Rapid surge in #GlobalWarming mainly due to reduced planetary #albedo, researchers suggest

"In addition to the influence of #ElNiño and the expected warming from anthropogenic #GreenhouseGas'es, several other factors have already been discussed that could have contributed to the surprisingly high global mean temperatures since 2023 ..."
But if all these factors are combined, there is still 0.2°C of warming with no readily apparent cause.

phys.org/news/2024-12-rapid-su

The world has been warming faster than expected. Scientists now think they know why

Story by Laura Paddison
December 5, 2024

"Last year was the hottest on record, oceans boiled, glaciers melted at alarming rates, and it left scientists scrambling to understand exactly why.

"They know the extraordinary heat was fueled by a number of factors, predominantly planet-heating pollution from burning fossil fuels and the natural climate pattern El Niño. But those alone did not explain the unusually rapid temperature rise.

"Now a new study published Thursday in the journal Science says it has identified the missing part of the puzzle: clouds.

"To be more specific, the rapid surge in warming was supercharged by a dearth of low-lying clouds over the oceans, according to the research — findings which may have alarming implications for future warming.

"In simple terms, fewer bright, low clouds mean the planet 'has darkened,' allowing it to absorb more sunlight, said Helge Goessling, a report author and climate physicist at the Alfred Wegener Institute in Germany.

"This phenomenon is called 'albedo' and refers to the ability of surfaces to reflect the sun’s energy back into space.

"The Earth’s albedo has been declining since the 1970s, according to the report, due in part to the melting of light-colored snow and sea ice, exposing darker land and water which absorb more of the sun’s energy, heating up the planet.

"Low clouds also feed into this effect as they reflect away sunlight.

"The scientists scoured NASA satellite data, weather data and climate models and found the decline in low clouds reduced the planet’s albedo to record lows last year. Areas including parts of the North Atlantic Ocean experienced a particularly significant fall, the study found.

"Last year fits into a decade-long decline of low cloud cover, Goessling told CNN.

"What the study can’t yet explain for certain is why this is happening. 'This is such a complex beast and so hard to disentangle,' Goessling said.

"He believes it is likely the result of a combination of factors. The first is a reduction in shipping pollution due to regulations aimed at reducing the industry’s harmful sulfur emissions. While this has been a win for human health, this type of pollution was also helping cool the planet by brightening clouds."

Read more:
msn.com/en-us/weather/topstori

www.msn.comMSN

In #LosAngeles hat eine Studie gezeigt, dass das Pflanzen von Bäumen und die Erhöhung der #Albedo von Oberflächen die hitzebedingten #Notaufnahmebesuche signifikant reduzieren können. In verschiedenen Szenarien wurde festgestellt, dass bis zu 50% der Notaufnahmebesuche während Hitzeereignissen vermieden werden könnten, insbesondere in hitzeanfälligen, einkommensschwachen Gemeinden mit hoher Bevölkerungsdichte.

#Hitzebekämpfung #Gesundheitsvorsorge #Stadtentwicklung

link.springer.com/article/10.1

SpringerLinkIncreasing tree cover and high-albedo surfaces reduces heat-related ER visits in Los Angeles, CA - International Journal of BiometeorologyThere is an urgent need for strategies to reduce the negative impacts of a warming climate on human health. Cooling urban neighborhoods by planting trees and vegetation and increasing albedo of roofs, pavements, and walls can mitigate urban heat. We used synoptic climatology to examine how different tree cover and albedo scenarios would affect heat-related morbidity in Los Angeles, CA, USA, as measured by emergency room (ER) visits. We classified daily meteorological data for historical summer heat events into discrete air mass types. We analyzed those classifications against historical ER visit data to determine both heat-related and excess morbidity. We used the Weather Research and Forecasting model to examine the impacts of varied tree cover and albedo scenarios on meteorological outcomes and used these results with standardized morbidity data algorithms to estimate potential reductions in ER visits. We tested three urban modification scenarios of low, medium, and high increases of tree cover and albedo and compared these against baseline conditions. We found that avoiding 25% to 50% of ER visits during heat events would be a common outcome if the urban environment had more tree cover and higher albedo, with the greatest benefits occurring under heat events that are moderate and those that are particularly hot and dry. We conducted these analyses at the county level and compared results to a heat-vulnerable, working-class Los Angeles community with a high concentration of people of color, and found that reductions in the rate of ER visits would be even greater at the community level compared to the county.

"Scientists have developed highly detailed maps showing where tree planting makes the most sense for maximizing climate benefits.

The complex interplay between #albedo, local #climates, and #reforestation efforts underscores the need for a nuanced approach to tree planting. It’s clear that reforestation is not a one-size-fits-all solution to climate change."

#trees
earth.com/news/could-tree-plan

Earth.comCould tree planting warm Earth? Science behind the albedo effectA new study reveals a hidden factor, the albedo effect, that could turn a well-intended tree-planting project into a climate misstep.

Observed #Arctic sea ice losses are a sentinel of anthropogenic #climate change.

These reductions are projected to continue with ongoing warming, ultimately leading to an ice-free Arctic.

The earliest ice-free conditions could occur in 2020–2030s under all emission trajectories and are likely to occur by 2050.

Replacing the reflective, white ice cover with dark sea surface will also decrease Earth's #albedo, amplifying the warming trajectory.

nature.com/articles/s43017-023

NatureProjections of an ice-free Arctic Ocean - Nature Reviews Earth & EnvironmentWith continued anthropogenic warming, an ice-free Arctic (sea ice area <1 million km2) is inevitable. This Review outlines the various characteristics of an ice-free Arctic, highlighting that future emission trajectories will determine where, how frequently and how long the Arctic will be ice free each year.