Tag Archives: gases

The Earth’s Sensitivity to Greenhouse Gases is Greater Than We Realized

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Climate change might be even more severe than previously estimated

kapook2981/getty images

The Earth’s climate appears to be more responsive to the pollution caused by greenhouse gases than previously assumed, making it harder to keep global temperature increases below 2°C.

This is concerning news for global efforts to combat climate change, according to Gunnar Myhre from Cicero International Climate Research Centre in Norway.

Researchers have long been aware that releasing greenhouse gases into the atmosphere can lead to climate warming with widespread consequences. However, the extent of potential warming due to these emissions remains uncertain. Specifically, how sensitive is the Earth’s climate to this pollution?

The primary uncertainty arises from how clouds react to warming atmospheres, as shifts in cloud systems could exacerbate warming through feedback loops.

Most predictions regarding warming by the century’s end are derived from climate models that incorporate various sensitivity assumptions. The model utilized by the Intergovernmental Panel on Climate Change indicates that if atmospheric concentrations double compared to pre-industrial levels, warming could range between 2°C and 5°C, prompting organizations to adopt a median estimate of 3°C.

Myhre and his team sought to align climate model predictions with satellite data showing the Earth’s energy imbalance—a measure of excess heat within our climate system, reflecting its sensitivity levels.

They discovered that less sensitive climate models, which suggest that the Earth’s climate is more resistant to greenhouse gas emissions, did not align with satellite data collected since the turn of the millennium. According to Myhre, models asserting that the Earth’s climate is less resistant to these gases are “more common.” He added, “Models predicting minimal warming are increasingly rare.”

The findings challenge the reliability of climate models forecasting warming below 2.9°C with doubled greenhouse gas concentrations. Instead, the data imply that warming beyond this threshold is more probable for the same level of pollution.

This has been corroborated by recent record-high temperatures observed both on land and in the sea since 2023, described as “strong climate feedback” in the atmosphere by Myhre.

A more sensitive climate necessitates a quicker reduction in emissions to maintain the same temperature trajectory. In essence, the world must accelerate decarbonization efforts to meet its climate commitments.

Johannes Kuas from the University of Leipzig in Germany argues that the study presents a “very plausible contention” that the Earth is indeed more sensitive to global warming than some models suggest, stating it “reduces the margin” for model estimations that scientists should follow. “It highlights the urgent need for political action against climate change,” he emphasized.

Richard Allen from the University of Reading in the UK notes that “natural climate change” could also be part of the narrative, by pointing out that satellite records date back only to 2001. Nevertheless, he describes the study as “rigorous” and adds, “there is further evidence that simulations predicting less warming are increasingly unrealistic in the long-term.”

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Source: www.newscientist.com

Chloride-containing deposits found on Mars by ESA’s Trace Gases Probe

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Chloride deposits are indicators of the presence of water on early Mars and have important implications for understanding the Martian climate and habitability. Color and Stereo Surface Imaging Systems Using the spacecraft (CaSSIS) aboard the European Space Agency's (ESA) Mars Trace Gases Explorer (TGO), planetary researchers conducted a planet-wide search for chloride-bearing deposits in Terra Sirenum and other parts of Mars.

This CaSSIS/TGO image shows chloride-bearing deposits (purple-colored scaly waves) in Terra Sirenum on Mars. Image credit: ESA/TGO/CaSSIS.

“Mars is currently a desert world, but around 3.5 billion years ago it was covered by rivers, lakes and possibly oceans,” said University of Bern researcher Valentin Bickel and his colleagues.

“The Cold Period began as Mars lost its magnetic field, could no longer retain its atmosphere, and water evaporated, froze, or became trapped within the surface.”

“Over time, the water disappeared, leaving behind mineral fingerprints on the surface.”

In this study, the researchers used neural networks to map potential chloride-bearing deposits in CaSSIS images across a large portion of Mars.

They identified a total of 965 potential chloride deposits ranging from 300 to 3,000 metres in diameter.

“These salt deposits probably formed from shallow pools or brines that evaporated in the sun,” the scientists said.

“Similar methods are used in saltwater pools on Earth to produce salt for human consumption.”

“Highly salty water could be a haven for life and an indicator of habitable parts of Mars,” the researchers added.

“Due to the high salinity, the water remains liquid even at minus 40 degrees.”

“The presence of chloride deposits, pictured above, and their direct association with liquid water, make areas like Terra Sirenum good targets for future robotic missions to search for signs of life.”

“While chloride-bearing terrains are not noticeable in regular black-and-white images, they show up as a distinct purple color in color infrared images, making CaSSIS a unique tool for studying the distribution of salts across Mars.”

“Our paper contains never-before-seen data that will help us better understand the distribution of water on Mars' distant past,” they said.

“TGO continues to image Mars from orbit to understand the planet's ancient past and potential habitability.”

“Not only will the spacecraft send back stunning images, it will also provide the best inventory of atmospheric gases and map water-rich areas on the planet's surface.”

“Understanding the history of water on Mars and whether it once allowed life to thrive is at the heart of ESA's ExoMars mission.”

Team paper Featured in this month's journal Scientific Data.

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VT Bickel others2024. Global dataset of potential chloride deposits on Mars identified by TGO CaSSIS. Scientific Data 11,845;doi: 10.1038/s41597-024-03685-3

Source: www.sci.news

Astrobiologists pinpoint five key greenhouse gases found on terraformed exoplanets

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The five man-made greenhouse gases identified by astrobiologist Edward Schwieterman of the University of California, Riverside, and his colleagues could be detected in relatively low concentrations in exoplanet atmospheres using the NASA/ESA/CSA James Webb Space Telescope and future space telescopes.

Diagram of the technological features of various planets, including artificial atmospheric gases. Image courtesy of Sohail Wasif / University of California, Riverside.

“For us, these gases are bad because we don’t want them to accelerate warming,” Dr Schwietermann said.

“But they could be useful to a civilization wanting to halt an impending ice age, or to terraform uninhabitable planets in its own system, as humanity has proposed for Mars.”

“These gases are not known to occur in large quantities in nature, so they have to be manufactured.”

“Finding them would therefore be evidence of the presence of intelligent, technological life forms. Such evidence is called a technosignature.”

The five gases proposed by the authors are used on Earth for industrial purposes, such as making computer chips.

These include fluorinated versions of methane, ethane and propane, as well as gases made of nitrogen and fluorine, or sulfur and fluorine.

One advantage is that it’s a very effective greenhouse gas — sulfur hexafluoride, for example, has a warming power 23,500 times that of carbon dioxide — and even a relatively small amount could heat a frozen planet to the point where liquid water could remain on the surface.

Another advantage of the proposed gas, at least from an alien perspective, is that it is extremely long-lived, surviving in an Earth-like atmosphere for up to 50,000 years.

“You won’t need to refill it very often to maintain a comfortable climate,” Dr. Schwieterman said.

Others suggest that refrigerant chemicals such as CFCs are technology signature gases because they are almost entirely man-made and visible in Earth’s atmosphere.

But unlike the chemically inert fully fluorinated gases discussed in the new paper, CFCs damage the ozone layer and may not be advantageous.

“If other civilizations had oxygen-rich atmospheres, they would have also had an ozone layer that they wanted to protect,” Dr Schwietermann said.

“CFCs will be broken down in the ozone layer while also catalyzing its destruction.”

“CFCs degrade easily and have a short lifespan, making them difficult to detect.”

Finally, for fluorinated gases to have an effect on climate, they need to absorb infrared radiation.

This absorption creates an infrared signature that can be detected by space telescopes.

Using current and planned technology, scientists may be able to detect these chemicals in nearby exoplanetary systems.

“In an Earth-like atmosphere, only one in a million molecules could be any of these gases and be detectable, and that concentration would be enough to even alter the climate,” Dr Schwietermann said.

To reach this calculation, the astrobiologists simulated a planet in the TRAPPIST-1 system, located about 40 light-years from Earth.

They chose this system because it contains at least seven rocky planets and is one of the best-studied planetary systems other than Earth.

Although it is not possible to quantify the likelihood of discovering man-made greenhouse gases in the near future, we are confident that, if they exist, they could be detected during missions currently planned to characterize the planet’s atmosphere.

“If telescopes are already characterizing planets for other reasons, there would be no need for extra effort to look for these technical features,” Dr Schwietermann said.

“And when you find them, it’s amazing.”

Team work Published in Astrophysical Journal.

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Edward W. Schwietermann others2024. Artificial greenhouse gases as a technological feature of exoplanets. ApJ 969, 20; doi: 10.3847/1538-4357/ad4ce8

Source: www.sci.news

New Satellite Launched to Monitor Emissions of Potent Greenhouse Gases

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MethaneSAT artist impressions

Environmental Defense Fund/NASA

A satellite that is expected to change the way we look at global warming methane emissions from oil and gas production has launched from California's Vandenberg Space Force Base. The satellite, called MethaneSAT, will orbit the Earth 15 times a day and use infrared sensors to measure methane leaking from all the world's major production centers.

“We specifically designed MethaneSAT to accomplish one goal,” he says. stephen hamburger The Environmental Defense Fund (EDF) is a nonprofit advocacy group that developed the satellite with a consortium of universities and aerospace companies. “To generate policy-relevant data to track methane emissions from the oil and gas industry around the world.”

Methane is the most important greenhouse gas after carbon dioxide. And oil, gas and coal production are among the largest sources of anthropogenic methane emissions. Many governments have set targets to reduce methane emissions by 30 percent by 2030, and at last year's COP28 climate change summit, many major oil and gas companies announced plans to reduce methane emissions by 30 percent by 2050. It pledged to reduce methane emissions to zero..

However, it is difficult to assess progress against these commitments. Current methane emissions remain poorly quantified, leaks are difficult to track, and aerial surveys and ground monitoring are expensive and some countries do not allow them. MethaneSAT joins a growing family of methane detection instruments in orbit, aiming to provide better visibility. Existing satellites, such as the European Space Agency's TROPOMI, detect methane emissions over large areas. Other devices, like the 11 methane detection devices operated by Canadian company GHGSat, focus on identifying specific point sources of methane.

In contrast, MethaneSAT regularly monitors methane at high resolution between these scales, allowing researchers to quantify emissions across regions associated with oil and gas production and identify possible sources. can be mapped. “We needed to be able to see all the emissions and resolve them in space,” Hamburg says.

When fully operational, the satellite will deliver up to 30 different “scenes” measuring methane fluxes over 40,000 square kilometers per day, according to the City of Hamburg. He said he will prioritize monitoring oil and gas producing regions such as the Permian Basin in West Texas, but will also be able to measure methane from other major sources such as agriculture, wetlands and landfills. “Methane is methane,” he says.

In parallel with the development of the satellite, Hamburg et al. are building a pipeline to rapidly convert the raw data it generates into publicly available estimates of methane emissions and the likely sources of plumes. was built. This includes a global database of oil and gas infrastructure. Created in partnership with Google Helps connect methane detection to its source.

“We're mapping the whole thing,” Hamburg says. He said the satellite will generate more data on methane emissions from oil and gas in its first year of operation than has been collected in the past 50 years. Full data collection is expected to begin in early 2025.

“The data is here and the technology is here to initiate action,” he says. Jean-François Gauthier GHGSat's hope is that MethaneSAT will help identify sources of emissions, allowing GHGSat's focused satellites to measure in more detail.

rob jackson Stanford University in California says the satellite can independently check emissions reported by companies and countries. “There will be nowhere to hide,” he says. The flood of data may also help explain the still-uncertain causes of the rise in methane rates since 2007, he added.

“The big question for me is how do people use that information,” Jackson says. “There's an assumption that if we had all the information, the emissions would somehow go away. But having information from aircraft and ground sources didn't stop these emissions.”

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Source: www.newscientist.com