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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 ice.

This 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.

The past year’s SMB is illustrated in the maps and charts below, based on data from the Polar Portal. The blue line in the upper chart shows the day-to-day SMB. Large snowfall events become visible as “spikes”. The blue line in the lower chart depicts the accumulated SMB, counted from the beginning of the “mass balance year” on 1 September 2023. In grey, the long-term average and its variability are shown. For comparison, the red line shows the record-low year of 2011-12.

The map shows the geographic spread of SMB gains (blue) and losses (red) for 2023-24, compared to the long-term average. This shows that southern Greenland had a relatively wet year compared to the long-term average, but the north-west and west lost more than usual. The spikes of snow and melt are clear in the graphs on the right.

2023-24 saw a close-to-average surface mass balance for the Greenland ice sheet
Left: Map showing the difference between the annual SMB in 2023-24 and the 1981-2010 period (in mm of ice melt). Blue shows ice gain compared to average and red shows ice loss with respect to average. Right: Daily (upper chart) and cumulative (lower chart) SMB of the Greenland ice sheet, in Gt/day and Gt, respectively. (1Gt is equal to 1 cubic kilometre.) Blue lines show the 2023-24 SMB year; the grey lines and areas show the 1981-2010 average and variability; and the red line in the lower chart shows the record low SMB year of 2011-12. Credit: DMI Polar Portal.

Heat over Europe and North America, cool over Greenland

While southern Europe sweltered through multiple heatwaves, northern Europe (with the exception of Arctic Scandinavia) had a rather cool and rainy July, followed by a warmer and sunnier late summer. Svalbard also suffered record temperatures and record amounts of glacier loss this year. 

And, yet, Greenland was spared these bouts of heat.

As in previous summer seasons, the comparatively wet and cool spells over the Greenland ice sheet were due to “blocking” weather patterns with ridges over North America and Europe and a trough in between over Greenland.

These high-pressure weather systems have a huge impact on weather extremes. Strong persistent blocks over North America and Europe were present in the course of the summer. This resulted in widespread heat near the cores of these high pressure areas and several heavy rainfall events in various European countries in May and June. 

In such a blocked flow, the jet stream is shaped like the Greek capital letter Omega (Ω). With the jet stream bulging up to the north over Canada and northern Europe, troughs of low pressure are found at each “foot” of the omega – including over Greenland. 

Svalbard was caught in one the opposite part of the omega with high temperatures and warm air directly over the islands, bringing large amounts of ice melt.

This contrast between Greenland on the one side and Svalbard and the eastern part of Canada is also a common pattern and shows how focusing on extremes in one region of the world means missing out on the opposite extreme in a different region.

The maps below show two examples of these recurring circulation patterns from late May/early June and mid-August. The blue shading shows the cool weather over Greenland (in the centre of the map), while the red shading shows the high temperatures over Canada, Europe and Svalbard .

Cool summer weather for Greenland in 2024
Map showing cool summer weather in Greenland (in centre of map) and heat over northern North America and northern and eastern Europe, particularly Fennoscandia (left panel) and Svalbard (right panel). Shading indicates temperatures that are warmer (red) or cooler (blue) than the long-term average for the time of year. The arrows show the circulation patterns in the atmosphere. Credit: DMI Polar Portal.

Snow accumulation

However, the surface mass budget is not just about ice melt.

September, October and November all saw above-average snowfall. Then, as in 2022-23, a rather dry period followed in late winter, followed by spikes in snow in March, April and May.

As a result, the accumulated SMB was close to the 1981-2010 average as melting began.

Subsequently, in June, several large snow fall events brought an emergency blanket back to the ice sheet, delaying the start of the “ablation” – or melt – season to 24 June, 11 days later than the 1981-2010 median. (The ablation season is defined as the first day of three days in a row with an SMB below -1Gt.)

The melt area was well above the average for the period of 1981-2010 during most of June, July and August – despite another spike in snow in August.

The left map shows the area of ice melt on 18 July – the day with the maximum melt extent (67%) of this summer (shaded in red). The map on the right shows the situation at the end of the season on 31 August when the ice sheet was well back into the winter pattern.

The charts beneath show the daily extent of melting across the ice sheet as a percentage (blue line), with the 1981-2010 average shown in grey.

Greenland's melt season in 2024 was mostly above average
Top: Map showing areas of Greenland undergoing surface melt on 18 July and 31 August 2024 (shaded red). Bottom: Percentage of ice sheet area seeing surface melt on each day of 2024 (blue line), ending on 18 July and 31 August, respectively. The grey line shows the 1981-2010 average. Credit: DMI Polar Portal.

The total mass budget

The surface budget is just one component of the “total” mass budget (TMB) of the Greenland ice sheet:

TMB = SMB + MMB + BMB

Here, MMB is the “marine” mass balance, consisting of the breaking off – or “calving” – of icebergs and the melting of the front of glaciers where they meet the warm sea water. BMB is the “basal” mass balance, which refers to ice losses from the base of the ice sheet. This makes a small, but non-zero, contribution to the TMB and mainly consists of frictional effects and the ground heat flux.

The figure below shows how much ice the Greenland ice sheet has lost (red) going back to 1987, which includes the SMB (blue), MMB (green) and BMB (orange).

For 2023-24, the TMB ended with a loss of 80Gt of ice. This means that 2023-24 was the 28th year in a row with a Greenland ice sheet overall mass loss. As the chart shows, Greenland last saw an annual net gain of ice in 1996.

2023-24 was the 28th year in a row where the Greenland ice sheet has lost mass overall
Chart showing the surface (blue), marine (green), basal (yellow) and total (red) mass balance for 1987 to 2024. Figures are in Gt per year. Based on updates to Mankoff et al. (2021)

Satellite data

Using data from the GRACE satellites, we can also estimate how much ice Greenland lost – independently from our calculations above.

The distance of these twin satellites changes slightly due to tiny gravity differences caused by mass changes. In addition, we can measure the speed at which ice flows through control points on the ice sheet where we know the thickness and shape of the ice. Thus, we can estimate MMB, the amount of ice being lost by the process of calving and submarine melting.

This data is openly available, allowing us to monitor the whole ice-sheet budget.

The map and graph below show the gain (blue) and loss (red) in the mass of ice. The difference in these mass changes over a glaciological year (September-August) is the TMB of the ice sheet for that particular year.

Satellite data reveals where the Greenland ice sheet is gaining and losing mass
Gain and loss in the total mass of ice of the Greenland ice sheet based on the GRACE and GRACE-FO satellites, updated until May 2024. Both missions are twin satellites separated by a distance of around 220km. This distance depends on gravity and can be measured very precisely. Gravity changes in turn are related to mass changes for example due to the loss of ice. GRACE was launched in March 2002, and the mission ended in October 2017. GRACE-FO was launched in May 2018. Therefore a gap exists between both missions. Shown is the month-by-month mass change in billions of tonnes (Gt) = cubic kilometres (km3). Also shown is the corresponding contribution to sea level rise; 100Gt is equivalent to 0.28mm of global sea level rise. All changes are given relative to April 2002.

According to the GRACE satellite data, most of the ice loss over 2023-24 occurred along the edge of the ice sheet, in particular along the west coast. This is backed up both by PROMICE observations and model data. In the interior of Greenland, a small increase in ice mass is found, as there is usually little or no snow melt in this region.

The graph illustrates the month-by-month development in changes of mass measured in gigatonnes, relative to April 2002. The left axis on the graph shows how this ice mass loss translates into a sea level rise contribution, where 100Gt corresponds to 0.28mm of global sea level rise.

Our calculations and the GRACE satellite data are entirely independent ways of estimating Greenland’s TMB, yet the results are quite closely aligned. From April 2002 to May 2024, the ice sheet losses amounted to 4,756Gt (calculations) and 4,911Gt (satellites) of ice.

As 1Gt of water is equivalent to a cube of 1 km by 1 km by 1 km, 360 of these cubes is equivalent to 1mm of sea level rise averaged around the whole globe.

This means that, since 2002, the Greenland ice sheet alone has contributed around 14mm to global average sea level rise.

The post Guest post: How the Greenland ice sheet fared in 2024 appeared first on Carbon Brief.

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Big fishing nations secure last-minute seat to write rules on deep sea conservation

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As a treaty to protect the High Seas entered into force this month with backing from more than 80 countries, major fishing nations China, Japan and Brazil secured a last-minute seat at the table to negotiate the procedural rules, funding and other key issues ahead of the treaty’s first COP.

The Biodiversity Beyond National Jurisdiction (BBNJ) pact – known as the High Seas Treaty – was agreed in 2023. It is seen as key to achieving a global goal to protect at least 30% of the planet’s ecosystems by 2030, as it lays the legal foundation for creating international marine protected areas (MPAs) in the deep ocean. The high seas encompass two-thirds of the world’s ocean.

Last September, the treaty reached the key threshold of 60 national ratifications needed for it to enter into force – a number that has kept growing and currently stands at 83. In total, 145 countries have signed the pact, which indicates their intention to ratify it. The treaty formally took effect on January 17.

    “In a world of accelerating crises – climate change, biodiversity loss and pollution – the agreement fills a critical governance gap to secure a resilient and productive ocean for all,” UN Secretary-General António Guterres said in a statement.

    Julio Cordano, Chile’s director of environment, climate change and oceans, said the treaty is “one of the most important victories of our time”. He added that the Nazca and Salas y Gómez ridge – off the coast of South America in the Pacific – could be one of the first intact biodiversity hotspots to gain protection.

    Scientists have warned the ocean is losing its capacity to act as a carbon sink, as emissions and global temperatures rise. Currently, the ocean traps around 90% of the excess planetary heat building up from global warming. Marine protected areas could become a tool to restore “blue carbon sinks”, by boosting carbon absorption in the seafloor and protecting carbon-trapping organisms such as microalgae.

    Last-minute ratifications

    Countries that have ratified the BBNJ will now be bound by some of its rules, including a key provision requiring countries to carry out environmental impact assessments (EIA) for activities that could have an impact on the deep ocean’s biodiversity, such as fisheries.

    Activities that affect the ocean floor, such as deep-sea mining, will still fall under the jurisdiction of the International Seabed Authority (ISA).

    Nations are still negotiating the rules of the BBNJ’s other provisions, including creating new MPAs and sharing genetic resources from biodiversity in the deep ocean. They will meet in one last negotiating session in late March, ahead of the treaty’s first COP (conference of the parties) set to take place in late 2026 or early 2027.

    China and Japan – which are major fishing nations that operate in deep waters – ratified the BBNJ in December 2025, just as the treaty was about to enter into force. Other top fishing nations on the high seas like South Korea and Spain had already ratified the BBNJ last year.

    Power play: Can a defensive Europe stick with decarbonisation in Davos?

    Tom Pickerell, ocean programme director at the World Resources Institute (WRI), said that while the last-minute ratifications from China, Japan and Brazil were not required for the treaty’s entry into force, they were about high-seas players ensuring they have a “seat at the table”.

    “As major fishing nations and geopolitical powers, these countries recognise that upcoming BBNJ COP negotiations will shape rules affecting critical commercial sectors – from shipping and fisheries to biotechnology – and influence how governments engage with the treaty going forward,” Pickerell told Climate Home News.

    Some major Western countries – including the US, Canada, Germany and the UK – have yet to ratify the treaty and unless they do, they will be left out of drafting its procedural rules. A group of 18 environmental groups urged the UK government to ratify it quickly, saying it would be a “failure of leadership” to miss the BBNJ’s first COP.

    Finalising the rules

    Countries will meet from March 23 to April 2 for the treaty’s last “preparatory commission” (PrepCom) session in New York, which is set to draft a proposal for the treaty’s procedural rules, among them on funding processes and where the secretariat will be hosted – with current offers coming from China in the city of Xiamen, Chile’s Valparaiso and Brussels in Belgium.

    Janine Felson, a diplomat from Belize and co-chair of the “PrepCom”, told journalists in an online briefing “we’re now at a critical stage” because, with the treaty having entered into force, the preparatory commission is “pretty much a definitive moment for the agreement”.

    Felson said countries will meet to “tidy up those rules that are necessary for the conference of the parties to convene” and for states to begin implementation. The first COP will adopt the rules of engagement.

    She noted there are “some contentious issues” on whether the BBNJ should follow the structure of other international treaties such as the Convention on Biological Diversity (CBD), as well as differing opinions on how prescriptive its procedures should be.

    “While there is this tension on how far can we be held to precedent, there is also recognition that this BBNJ agreement has quite a bit to contribute in enhancing global ocean governance,” she added.

    The post Big fishing nations secure last-minute seat to write rules on deep sea conservation appeared first on Climate Home News.

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    Climate at Davos: Energy security in the geopolitical driving seat 

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    The annual World Economic Forum got underway on Tuesday in the Swiss ski resort of Davos, providing a snowy stage for government and business leaders to opine on international affairs. With attention focused on the latest crisis – a potential US-European trade war over Greenland – climate change has slid down the agenda.

    Despite this, a number of panels are addressing issues like electric vehicles, energy security and climate science. Keep up with top takeaways from those discussions and other climate news from Davos in our bulletin, which we’ll update throughout the day.

    From oil to electrons – energy security enters a new era

    Energy crises spurred by geopolitical tensions are nothing new – remember the 1970s oil shock spurred by the embargo Arab producers slapped on countries that had supported Israel during the Yom Kippur War, leading to rocketing inflation and huge economic pain.

    But, a Davos panel on energy security heard, the situation has since changed. Oil now accounts for less than 30% of the world’s energy supply, down from more than 50% in 1973. This shift, combined with a supply glut, means oil is taking more of a back seat, according to International Energy Agency boss Fatih Birol.

    Instead, in an “age of electricity” driven by transport and technology, energy diplomacy is more focused on key elements of that supply chain, in the form of critical minerals, natural gas and the security buffer renewables can provide. That requires new thinking, Birol added.

    “Energy and geopolitics were always interwoven but I have never ever seen that the energy security risks are so multiplied,” he said. “Energy security, in my view, should be elevated to the level of national security today.”

    In this context, he noted how many countries are now seeking to generate their own energy as far as possible, including from nuclear and renewables, and when doing energy deals, they are considering not only costs but also whether they can rely on partners in the long-term.

      In the case of Europe – which saw energy prices jump after sanctions on Russian gas imports in the wake of Moscow’s invasion of Ukraine – energy security rooted in homegrown supply is a top priority, European Commission President Ursula von der Leyen said in Davos on Tuesday.

      Outlining the bloc’s “affordable energy action plan” in a keynote speech at the World Economic Forum, she emphasised that Europe is “massively investing in our energy security and independence” with interconnectors and grids based on domestically produced sources of power.

      The EU, she said, is trying to promote nuclear and renewables as much as possible “to bring down prices and cut dependencies; to put an end to price volatility, manipulation and supply shocks,” calling for a faster transition to clean energy.

      “Because homegrown, reliable, resilient and cheaper energy will drive our economic growth and deliver for Europeans and secure our independence,” she added.

      Comment – Power play: Can a defensive Europe stick with decarbonisation in Davos?

      AES boss calls for “more technical talk” on supply chains

      Earlier, the energy security panel tackled the risks related to supply chains for clean energy and electrification, which are being partly fuelled by rising demand from data centres and electric vehicles.

      The minerals and metals that are required for batteries, cables and other components are largely under the control of China, which has invested massively in extracting and processing those materials both at home and overseas. Efforts to boost energy security by breaking dependence on China will continue shaping diplomacy now and in the future, the experts noted.

      Copper – a key raw material for the energy transition – is set for a 70% increase in demand over the next 25 years, said Mike Henry, CEO of mining giant BHP, with remaining deposits now harder to exploit. Prices are on an upward trend, and this offers opportunities for Latin America, a region rich in the metal, he added.

      At ‘Davos of mining’, Saudi Arabia shapes new narrative on minerals

      Andrés Gluski, CEO of AES – which describes itself as “the largest US-based global power company”, generating and selling all kinds of energy to companies – said there is a lack of discussion about supply chains compared with ideological positioning on energy sources.

      Instead he called for “more technical talk” about boosting battery storage to smooth out electricity supply and using existing infrastructure “smarter”. While new nuclear technologies such as small modular reactors are promising, it will be at least a decade before they can be deployed effectively, he noted.

      In the meantime, with electricity demand rising rapidly, the politicisation of the debate around renewables as an energy source “makes no sense whatsoever”, he added.

      The post Climate at Davos: Energy security in the geopolitical driving seat  appeared first on Climate Home News.

      Climate at Davos: Energy security in the geopolitical driving seat 

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      A Record Wildfire Season Inspires Wyoming to Prepare for an Increasingly Fiery Future

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      As the Cowboy State faces larger and costlier blazes, scientists warn that the flames could make many of its iconic landscapes unrecognizable within decades.

      In six generations, Jake Christian’s family had never seen a fire like the one that blazed toward his ranch near Buffalo, Wyoming, late in the summer of 2024. Its flames towered a dozen feet in the air, consuming grassland at a terrifying speed and jumping a four-lane highway on its race northward.

      A Record Wildfire Season Inspires Wyoming to Prepare for an Increasingly Fiery Future

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