Oceans & Ice - Haggard Earth

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The Greenland ice sheet melt season for this year is over, resulting in the 28th year in a row in which Greenland has lost its.Carbon Brief Dr Martin Stendel, a climate scientist at the Danish Meteorological Institute (DMI) in Copenhagen, which is part of the Polar Portal.Dr Ruth Mottram, a climate scientist at DMI.11-11-2024This has been a spiky year for Greenland – a mix of highs from abundant snow in winter and lows from some very high melt days in summer. Those spikes of high snowfall delayed the onset of the melt season in June and reduced melt substantially in August. Fresh snow is a brighter white than old glacier ice, so summer snow effectively acted as a shiny protective blanket – just when the high melt season was getting going. The 2023-24 year, as the year before, had strong melt rates throughout the northern-hemisphere summer, but also above average snowfall during winter and in June. As a result, the balance between accumulated snow and melting ice on Greenland’s surface ended above the 1981-2010 average. The increase in both melt and snowfall are exactly what scientists expect in a warming climate. But, overall, Greenland has again lost more ice than it gained – even though, as in previous years, Greenland was comparably cool compared to North America and Europe. High “calving” rates – the breaking off of icebergs at the face of the ice sheet – meant that Greenland lost 80bn tonnes of ice over the 12 months from September 2023 to August 2024. The last year to see a net gain of ice is still 1996. This marks the 10th year of these annual reviews – see our previous annual analysis for 2023, 2022, 2021, 2020, 2019, 2018, 2017, 2016 and 2015.

Surface melt.....Greenland’s annual cycle covers the 12 months from the previous September up to the end of August. Over this period, we calculate the “surface mass budget” (SMB) for the ice sheet. The SMB is akin to the bank account for the surface of the Greenland ice sheet. It is the balance between gains (from snowfall) and losses (from ice melt and runoff). As the ice sheet largely gains snow from September, accumulating ice through autumn, winter and into spring, we start the ice budget year on 1 September. Then, as the year warms up into late spring, the ice sheet begins to lose more ice through surface melt than it gains from fresh snowfall, generally from the mid of June. This melt season usually continues until the middle or end of August, the end of the surface budget year. Snowfall is the only way for the ice sheet to gain mass. Therefore, for the size of the ice sheet to remain constant, this snow must outweigh all other ways the ice sheet can lose ice – iceberg calving, melt at the base of the ice sheet and evaporation from the surface..According to our calculations, the Greenland ice sheet ended the year 2023-24 with an overall SMB of about 367bn tonnes (Gt). This is the 19th highest SMB in a dataset that goes back 44 years, and it is close to the 1981-2010 average of 348 Gt......there's a lot more- text, maps, graphs https://www.carbonbrief.org/guest-post-how-the-greenland-ice-sheet-fared-in-2024/?utm_source=cbnewsletter&utm_medium=email&utm_term=2024-11-28&utm_campaign=Daily+Briefing+27+11+2024

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Oceans face ‘triple threat’ of extreme heat, oxygen loss and acidification. A fifth of world’s ocean surface particularly vulnerable to threats driven by burning fossil fuel and deforestation, new research finds.Guardian Oliver Milman Tue 4 Jun 2024 The world’s oceans are facing a “triple th eat” of extreme heating, a loss of oxygen and acidification, with extreme conditions becoming far more intense in recent decades and placing enormous stress upon the planet’s panoply of marine life, new research has found. About a fifth of the world’s ocean surface is particularly vulnerable to the three threats hitting at once, spurred by human activity such as the burning of fossil fuels and deforestation, the study found. In the top 300 meters of affected ocean, these compound events now last three times longer and are six times more intense than they were in the early 1960s, the research states. The study’s lead author warned that the world’s oceans were already being pushed into an extreme new state because of the climate crisis. “The impacts of this have already been seen and felt,” said Joel Wong, a researcher at ETH Zurich, who cited the well-known example of the heat “blob” that has caused the die-off of marine life in the Pacific Ocean. “Intense extreme events like these are likely to happen again in the future and will disrupt marine ecosystems and fisheries around the world,” he added. The research, published in AGU Advances, analyzed occurrences of extreme heat, deoxygenation and acidification and found that such extreme events can last for as long as 30 days, with the tropics and the north Pacific particularly affected by the compounding threats. Climate scientists have been alarmed by the relentless onward rise of heat in the ocean, which has hit extraordinary heights in recent months. “The heat has been literally off the charts, it’s been astonishing to see,” said Andrea Dutton, a geologist and climate scientist at the University of Wisconsin.......read on https://news.climate.columbia.edu/2020/12/16/buying-stuff-drives-climate-change/

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Cleaning up cruise ships’ environmental wake. Monga Bay Sean Mowbray 4 Oct 2023

or years, campaigners have highlighted the unsustainable practices of the cruise ship industry, including the massive vessels’ Fdumping of sewage and wastewater, and their emissions of air pollutants and greenhouse gases.
The cruise industry says it’s working hard to limit its environmental footprint, with the adoption of advanced wastewater treatment systems, cleaner fuels, and other sustainability measures.
Jurisdictions around the globe have begun tightening rules to limit the effects of visiting ships.
Critics and advocates remain unconvinced, arguing that much more needs to be done at a far faster pace to tackle cruisers’ global impact on the ocean and air.

In July, Amsterdam became the latest in a series of cities to regulate against huge cruise ships in an attempt to tackle pollution and the burden of overtourism. The Dutch capital joins other cities, such as Venice in Italy, Monterey Bay in California, and Bar Harbor in Maine, in seeking to limit the impact of cruises.

Around the same time, Transport Canada, a national regulator, took its own steps to tackle cruise waste: It upgraded measures that prohibit ship wastewater disposal in the sea from voluntary to mandatory. For years, Canada’s national waters were likened to a “toilet bowl” due to lax regulations enabling cruise ships passing through the country’s waters to dump sewage at will, according to campaigners.

“Making the voluntary program into a mandatory one allows enforcement to come in and brings the possibility of fines,” Anna Barford, shipping campaigner for U.S.- and Canada-based NGO Stand.Earth, told Mongabay. She said cruisers dumped as much as 32 billion liters (8.45 billion gallons) of waste in Canadian waters in 2019. “This is absolutely a good and right step.”

Meanwhile, the cruise industry says it’s working hard to limit its environmental footprint across the globe, including greenhouse gas emissions and harm to oceans and air. Critics and advocates argue that much more needs to be done at a far faster pace to tackle cruisers’ global impact.

U.S.-based NGO Friends of the Earth releases an annual scorecard that grades cruise ship companies on their environmental impacts. The most recent, from 2022, looked at 18 major cruise lines, giving the top overall grade, a C+, to a single company. Three others received C-range grades, seven got D-range grades, and seven got the lowest grade: an F. Despite the poor overall scores, some companies are improving when it comes to issues such as air and water pollution, said Marcie Keever, the group’s oceans and vessels program director. But the industry writ large remains mired in harmful activities, underpinned by a general lack of transparency by many players, she said. https://news.mongabay.com/2023/10/cleaning-up-cruise-ships-environmental-wake/

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What was behind the seismic boom that wrapped Earth for 9 days? Climate change's latest mystery came from Greenland's melting ice sheet

Grist

Sachi Kitajima Mulkey Sep 25, 2024 It was a warning shot picked up by seismometers around the world. Last September, a melting glacier collapsed, sending the mountaintop it propped up careening into the Dickson Fjord in East Greenland. The impact created a 650-foot tall tsunami — twice as tall as the Statue of Liberty — which crashed back and forth between the steep, narrow walls of the channel, booming so loud that the vibrations wrapped the globe in a 90-second interval pulse for nine straight days. The resulting paper, recently published in Science, blames human-made global warming for the collapse. A century of greenhouse gases heating up the atmosphere have eroded swaths of the Greenland ice sheet — frozen freshwater that holds back 23 feet of potential sea level rise. Hicks said this kind of landslide-tsunami has never been seen in East Greenland, an area that tends to experience less melt than the country’s Western perimeter. It could be a one-off, random event, or a sign of spreading instability. “We can maybe expect more of these events in the future,” Hicks said.

Another group of researchers, from the University of Barcelona, recently confirmed the ice sheet’s trajectory. Their study, published in the Journal of Climate by the American Meteorological Society, found that days of extreme melt, linked to periods of hot, stagnant air in the summer, have doubled in frequency and also intensified since 1950. Roughly 40 percent of the ice Greenland loses in a year occurs during these extreme melting events.*

“Each episode of melting is becoming more intense and frequent than in the past,” said Josep Bonsoms, a geography researcher at the University of Barcelona and the study’s lead author. For instance, an extreme melting event in 2012 led to the loss of 610 gigatons of ice, enough to fill Lake Erie, and then some. According to the University of Barcelona researchers, even days of average melt, often influenced by the same weather conditions as extreme days, contribute to worsening melt in the future. Although their study did not make predictions, Bonsoms says the pattern will likely continue to accelerate as the planet heats up. Take this summer. Greenland experienced above average melt, according to the National Snow and Ice Data Center, but not enough to be considered extreme. In July, two heat waves ate away at the snowfall in the western area of the ice sheet, depleting its ability to reflect sunlight, known as albedo. When the darker, glacial ice beneath it became exposed, the land absorbed more heat, intensifying the melt.

On a bigger scale, this type of feedback loop is one of the reasons that the region is warming four times faster than the rest of the planet, a phenomenon known as Arctic amplification. Tyler Jones, an Arctic researcher at the University of Colorado, Boulder, said that among the many catalysts driving Arctic amplification, “the most important is the loss of sea ice.” Unlike Greenland’s land-bound ice, these floating patches of sea ice don’t directly contribute to sea level rise when they melt, but their albedo acts like a giant mirror reflecting the sun’s heat. “If you remove that giant mirror, all of a sudden that incoming solar energy gets absorbed by the ocean,” Jones said. Because the ocean can trap and store so much heat, this means the entire region becomes warmer even in the winter. The amount of sea ice remaining in September, the end of the annual melt season, has almost halved since the 1980s — with hardly any older than four years surviving. This year, global sea ice levels neared record lows. ,“We’re in a new climate regime. We are seeing extremes that just weren’t in our records of climate ever, just now appearing before us,” Jones said. Because the melting is self-perpetuating, he says, the ice sheet will continue to destabilize until the damage is irreversible. And as sea levels continue to rise, coastal communities around the world will have to adapt to a new world of extremes their cities weren’t built for.......read on https://grist.org/science/seismic-boom-earth-greenland-glacier/?utm_medium=email&utm_source=newsletter&utm_campaign=weekly

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Revolutionary scientific discovery upends deep sea mining negotiations.National Observer John Woodside News Business Energy Politics August 6th 2024 Mining the ocean floor for critical minerals was already controversial, but a new groundbreaking scientific study has thrown the industry into chaos as countries negotiate its future. At a meeting of the United Nations’ International Seabed Authority (ISA) in Jamaica, running from July 15 to Aug 2, countries are negotiating rules to govern deep sea mining. The regulations have been under development for years, but the clock has been running out on an agreement. But as the negotiations were underway this year, a major study published in Nature Geoscience did more than just expose potential harms to ocean ecosystems due to mining – it revolutionized humans' understanding of how our world works. Mining on the seafloor could affect oxygen levels, and threaten biorich ecosystems in previously unknown ways.

Scientists discovered what they called “dark oxygen.” Until this paper, oxygen was believed to be created solely through photosynthesis, the process by which plants, algae and certain types of bacteria, consume light and produce oxygen. Dark oxygen, by contrast, is created deep in the ocean where sunlight does not reach; in pitch blackness, somehow oxygen was being produced. For years the scientists dismissed the findings, attributing it to faulty equipment, until finally the conclusion was inescapable. Something was producing oxygen deep below the surface. Mining the ocean floor for critical minerals was already controversial, but a new groundbreaking scientific study has thrown the industry into chaos as countries negotiate its future. At a meeting of the United Nations’ International Seabed Authority (ISA) in Jamaica, running from July 15 to Aug 2, countries are negotiating rules to govern deep sea mining. The regulations have been under development for years, but the clock has been running out on an agreement.

But as the negotiations were underway this year, a major study published in Nature Geoscience did more than just expose potential harms to ocean ecosystems due to mining – it revolutionized humans' understanding of how our world works. Mining on the seafloor could affect oxygen levels, and threaten biorich ecosystems in previously unknown ways. Scientists discovered what they called “dark oxygen.” Until this paper, oxygen was believed to be created solely through photosynthesis, the process by which plants, algae and certain types of bacteria, consume light and produce oxygen. Dark oxygen, by contrast, is created deep in the ocean where sunlight does not reach; in pitch blackness, somehow oxygen was being produced. For years the scientists dismissed the findings, attributing it to faulty equipment, until finally the conclusion was inescapable. Something was producing oxygen deep below the surface.

To power the green economy we need to extract metals... So what we have discovered means that we’re going to have to carefully think about if deep ocean mining goes ahead, where that mining should take place." The scientists describe “polymetallic nodules” – lumps of rock containing minerals found around four kilometeres deep that produce a small electric current. That electric current is believed to be splitting water into hydrogen and oxygen in a process called saltwater electrolysis, similar to how hydrogen can be produced using an electric current to split water into oxygen and hydrogen. The Metals Company wants to mine those nodules and sell them to produce batteries needed for the energy transition. The scientific study that found the nodules produce oxygen was funded in part by the company. During a press conference Thursday, Greenpeace International’s deep sea mining lead Lousia Casson said the findings — that the very minerals mining companies are after could be producing oxygen in total darkness — has set the debate over the industry’s future alight. “This is a really revolutionary discovery. It fundamentally changes our understanding of how oxygen is produced on planet Earth,” she said. The findings have “been brought up directly by a number of delegations, from Latin America and Europe inside these negotiations as a clear reason for precaution.”....read on https://www.nationalobserver.com/2024/08/06/news/revolutionary-scientific-discovery-upends-deep-sea-mining-negotiations

Library

2024- 28th Year in a row in which Greenland has Lost its Surface Ice

Oceans face ‘Triple Threat’ of extreme heat, oxygen loss and acidification. A fifth of World’s Ocean Surface driven by burning Fossil Fuel and Deforestation,

Cleaning up Cruise Ships’ Environmental Wake.

Climate Change's latest Mystery came from Greenland's Melting Ice Sheet

Revolutionary Scientific Discovery Upends Deep Sea Mining Negotiations.

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