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The Greenland ice sheet melt season 2023 is now over and it completes a 27th year in a row in which Greenland has lost ice.

The 2022-23 year saw both very high melt, particularly in July, but also higher than usual rain and snowfall in the late spring and early summer.

The increase in both melt and snowfall are exactly what scientists expect in a warming climate, and although they have tended to balance each other to some extent, Greenland has still ended up losing more ice than it gained.

As in previous years, while very high temperatures hit North America and Europe this summer, Greenland in between was comparably cool and wet. However, this was not enough to stop Greenland losing ice.

Extended snowfalls from October to December 2022 and the late onset of the melt season contributed to a relatively large accumulation of mass on Greenland’s surface. Nonetheless, this could not outweigh the losses by surface melting and breaking off of icebergs.

Overall, Greenland’s ice sheet lost 196 billion tonnes (Gt) of ice over the 12 months from September 2022 to August 2023.

This means that the last year to see a net gain of ice is still 1996.

In this annual guest post, we discuss the processes of ice sheet melt, glacier “calving” and the weather and climate that explain these losses.

(See our previous annual analysis for 2022, 2021, 2020, 2019, 2018, 2017, 2016 and 2015.)

Surface melt

Greenland’s annual cycle covers the 12 months up until the end of August.

The pattern sees the ice sheet largely gain snow from September, accumulating ice through autumn, winter and into spring. 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 end of June. This melt season usually continues until the middle or end of August.

The snow gains and ice losses at the ice sheet’s surface over these 12 months are the “surface mass balance” (SMB) of the ice sheet. The SMB consists of gains through snowfall and losses through runoff and evaporation. Therefore, snowfall is the only way for the ice sheet to gain mass.

The data suggest that the Greenland ice sheet ended the year 2022-23 with a total SMB of about 398Gt. This is the 15th highest SMB in a dataset that goes back 43 years and is quite close to the 1981-2010 average.

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 2022. In grey, the long-term average and its variability are shown. The red line shows the record low year of 2011-12 for comparison.

The map shows the geographic spread of SMB gains (blue) and losses (red) for 2022-23, compared to the long-term average.

Map showing the difference between the annual SMB in 2022-23 and the 1981-2010 period (in mm of ice melt).
Left: Map showing the difference between the annual SMB in 2022-23 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 billions of tonnes per day (Gt/day) and billions of tonnes (Gt), respectively. 1Gt is equal to 1 cubic kilometre. Blue lines show the 2022-23 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 North America and Europe, cool over Greenland

A closer look at the weather and ice sheet changes through the past 12 months reveals some interesting developments.

Early winter began with above-average snowfall on several occasions in September, October, November and December. In late winter, a rather dry period followed, so that the accumulated SMB was close to – and then slightly below – average as melting began.

The most remarkable feature in the evolution of the SMB in 2023 was the extended period of growth in June. At the end of that month, the accumulated SMB was almost 150Gt above average.

The effect of this extra snow meant that the onset of the melt – or “ablation” season was on 29 June – 16 days later than the 1981-2022 median. The ablation season is defined as the first day of three days in a row with an SMB below -1Gt.

As in previous summer seasons, the reason for the comparatively wet and cool spells over the Greenland ice sheet can be found quite far away from Greenland in “blocking” weather patterns. 

These high-pressure weather systems have a huge impact on weather extremes. Strong persistent blocks over North America and Europe were present in the end of May and the first decade of June and at the end of August. The last of these caused catastrophic rainfall in Greece and Libya. 

In such a blocked flow, the jet stream is shaped like the Greek capital letter Omega (Ω). Research suggests that such patterns in recent years have been stronger and more persistent. 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. 

The map below shows an example of the recurring circulation patterns, bringing cool weather over Greenland (blue shading) along with high temperatures over Canada and Europe (red shading).

Map showing cool summer weather in Greenland (in centre of map) and heat over northern North America and western Europe, particularly Scandinavia.
Map showing cool summer weather in Greenland (in centre of map) and heat over northern North America and western Europe, particularly Scandinavia. 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.

The melt season that followed was stronger than average – even comparable with the record years of 2012 and 2019 – with melting over more than 50% of the ice sheet for 29 days in a row, from 27 June to 25 July.

And while the world was rightly focused on other extreme weather events this summer, the Greenland summer also saw its own record-breaking conditions.

The station at the summit of Greenland – about 3,000 metres above sea level – recorded a new average temperature record of -7.3C, almost 2C warmer than the previous record of -9.2C set in 2012 and 4C warmer than the long-term average at summit station.

Melt season

There were two main melting periods of the ablation season. Despite the cool start, as the melt season got underway there was a period of very high temperatures at the end of July. This brought intense melt all around the ice sheet that led to very large ice losses over a few days.

The map on the left side shows the area of ice melt on 10 July when the maximum melt extent (67%) of this summer (shaded in red) was reached. The centre map shows the second melt maximum (50%), which peaked on 23 August, and finally the map on the right depicts the situation at the end of the season on 31 August. Melting was above average from 21 June through to – and beyond – the end of the season.

Map showing areas of Greenland undergoing surface melt on 10 July, 23 August and 31 August 2023 (shaded red).
Top: Map showing areas of Greenland undergoing surface melt on 10 July, 23 August and 31 August 2023 (shaded red). Bottom: Percentage of ice sheet area seeing surface melt on each day of 2023 (blue line), ending on 28 July, 23 August and 31 August, respectively. The grey line shows the 1981-2010 average. Credit: DMI Polar Portal.

Components of the mass balance

The SMB is just one component of the “total” mass mass balance (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 the components of the TMB (red) going back to 1987, which includes the SMB (blue), MMB (green) and BMB (orange). These estimates are based on the modelling approach set out in Mankoff et al in 2021.

For the past year, the TMB clocked in at a loss of 196Gt of ice. This means that 2022-23 was the 27th year in a row where the Greenland ice sheet has lost mass overall. As the chart shows, Greenland last saw an annual net gain of ice in 1996.

Chart showing the surface (blue), marine (green), basal (yellow) and total (red) surface mass balance for 1987 to 2023.
Chart showing the surface (blue), marine (green), basal (yellow) and total (red) surface mass balance for 1987 to 2023. Figures are in Gt per year. Chart by Carbon Brief, based on updates to Mankoff et al. (2021)

The only way for the ice sheet to gain ice is via the SMB – that is, through snowfall. The other components, MMB and BMB, are always negative, so the surplus of snowfall over runoff and the two other components needs to be large enough to compensate.

Using data from the GRACE satellites, we can estimate the TMB independently. The distance of these twin satellites changes slightly due to tiny gravity differences caused by mass changes. Expressing these distance differences as mass changes is not straightforward, however, which is the reason why GRACE data are only made available a few months later.

Furthermore, using satellites, 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.

Gain and loss in the total mass of ice of the Greenland ice sheet based on the GRACE and GRACE-FO satellites.
Gain and loss in the total mass of ice of the Greenland ice sheet based on the GRACE and GRACE-FO satellites. 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). 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.

The map shows that most of the loss of ice occurs along the edge of the ice sheet, where independent observations also indicate that the ice is thinning. High up in central Greenland, there is a small increase in the mass of the ice – most likely due to a small increase in snowfall, as we would also expect in a warming climate.

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.

The two approaches to calculating TMB have a common period of 1 April 2002 to 31 March 2023. These estimates suggest that the Greenland ice sheet lost around 4,578Gt (Mankoff et al.) to 4,745Gt (GRACE) of ice over this time. Note that the two methods are completely independent.

The result from both datasets is equivalent to around 13mm of global average sea level rise. Recent research suggests that the imbalance of the Greenland ice sheet caused by climate change means it is committed to contributing at least 274mm to global sea levels in future, regardless of 21st-century climate pathways.

The post Guest post: How the Greenland ice sheet fared in 2023 appeared first on Carbon Brief.

Guest post: How the Greenland ice sheet fared in 2023

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For proof of the energy transition’s resilience, look at what it’s up against

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Al-Karim Govindji is the global head of public affairs for energy systems at DNV, an independent assurance and risk management provider, operating in more than 100 countries.

Optimism that this year may be less eventful than those that have preceded it have already been dealt a big blow – and we’re just weeks into 2026. Events in Venezuela, protests in Iran and a potential diplomatic crisis over Greenland all spell a continuation of the unpredictability that has now become the norm.

As is so often the case, it is impossible to separate energy and the industry that provides it from the geopolitical incidents shaping the future. Increasingly we hear the phrase ‘the past is a foreign country’, but for those working in oil and gas, offshore wind, and everything in between, this sentiment rings truer every day. More than 10 years on from the signing of the Paris Agreement, the sector and the world around it is unrecognisable.

The decade has, to date, been defined by a gritty reality – geopolitical friction, trade barriers and shifting domestic priorities – and amidst policy reversals in major economies, it is tempting to conclude that the transition is stalling.

Truth, however, is so often found in the numbers – and DNV’s Energy Transition Outlook 2025 should act as a tonic for those feeling downhearted about the state of play.

While the transition is becoming more fragmented and slower than required, it is being propelled by a new, powerful logic found at the intersection between national energy security and unbeatable renewable economics.

A diverging global trajectory

The transition is no longer a single, uniform movement; rather, we are seeing a widening “execution gap” between mature technologies and those still finding their feet. Driven by China’s massive industrial scaling, solar PV, onshore wind and battery storage have reached a price point where they are virtually unstoppable.

These variable renewables are projected to account for 32% of global power by 2030, surging to over half of the world’s electricity by 2040. This shift signals the end of coal and gas dominance, with the fossil fuel share of the power sector expected to collapse from 59% today to just 4% by 2060.

    Conversely, technologies that require heavy subsidies or consistent long-term policy, the likes of hydrogen derivatives (ammonia and methanol), floating wind and carbon capture, are struggling to gain traction.

    Our forecast for hydrogen’s share in the 2050 energy mix has been downgraded from 4.8% to 3.5% over the last three years, as large-scale commercialisation for these “hard-to-abate” solutions is pushed back into the 2040s.

    Regional friction and the security paradigm

    Policy volatility remains a significant risk to transition timelines across the globe, most notably in North America. Recently we have seen the US pivot its policy to favour fossil fuel promotion, something that is only likely to increase under the current administration.

    Invariably this creates measurable drag, with our research suggesting the region will emit 500-1,000 Mt more CO₂ annually through 2050 than previously projected.

    China, conversely, continues to shatter energy transition records, installing over half of the world’s solar and 60% of its wind capacity.

    In Europe and Asia, energy policy is increasingly viewed through the lens of sovereignty; renewables are no longer just ‘green’, they are ‘domestic’, ‘indigenous’, ‘homegrown’. They offer a way to reduce reliance on volatile international fuel markets and protect industrial competitiveness.

    Grids and the AI variable

    As we move toward a future where electricity’s share of energy demand doubles to 43% by 2060, we are hitting a physical wall, namely the power grid.

    In Europe, this ‘gridlock’ is already a much-discussed issue and without faster infrastructure expansion, wind and solar deployment will be constrained by 8% and 16% respectively by 2035.

    Comment: To break its coal habit, China should look to California’s progress on batteries

    This pressure is compounded by the rise of Artificial Intelligence (AI). While AI will represent only 3% of global electricity use by 2040, its concentration in North American data centres means it will consume a staggering 12% of the region’s power demand.

    This localized hunger for power threatens to slow the retirement of fossil fuel plants as utilities struggle to meet surging base-load requirements.

    The offshore resurgence

    Despite recent headlines regarding supply chain inflation and project cancellations, the long-term outlook for offshore energy remains robust.

    We anticipate a strong resurgence post-2030 as costs stabilise and supply chains mature, positioning offshore wind as a central pillar of energy-secure systems.

    Governments defend clean energy transition as US snubs renewables agency

    A new trend is also emerging in behind-the-meter offshore power, where hybrid floating platforms that combine wind and solar will power subsea operations and maritime hubs, effectively bypassing grid bottlenecks while decarbonising oil and gas infrastructure.

    2.2C – a reality check

    Global CO₂ emissions are finally expected to have peaked in 2025, but the descent will be gradual.

    On our current path, the 1.5C carbon budget will be exhausted by 2029, leading the world toward 2.2C of warming by the end of the century.

    Still, the transition is not failing – but it is changing shape, moving away from a policy-led “green dream” toward a market-led “industrial reality”.

    For the ocean and energy sectors, the strategy for the next decade is clear. Scale the technologies that are winning today, aggressively unblock the infrastructure bottlenecks of tomorrow, and plan for a future that will, once again, look wholly different.

    The post For proof of the energy transition’s resilience, look at what it’s up against appeared first on Climate Home News.

    For proof of the energy transition’s resilience, look at what it’s up against

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    Post-COP 30 Modeling Shows World Is Far Off Track for Climate Goals

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    A new MIT Global Change Outlook finds current climate policies and economic indicators put the world on track for dangerous warming.

    After yet another international climate summit ended last fall without binding commitments to phase out fossil fuels, a leading global climate model is offering a stark forecast for the decades ahead.

    Post-COP 30 Modeling Shows World Is Far Off Track for Climate Goals

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    IMO head: Shipping decarbonisation “has started” despite green deal delay

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    The head of the United Nations body governing the global shipping industry has said that greenhouse gases from the global shipping industry will fall, whether or not the sector’s “Net Zero Framework” to cut emissions is adopted in October.

    Arsenio Dominguez, secretary-general of the International Maritime Organization, told a new year’s press conference in London on Friday that, even if governments don’t sign up to the framework later this year as planned, the clean-up of the industry responsible for 3% of global emissions will continue.

    “I reiterate my call to industry that the decarbonisation has started. There’s lots of research and development that is ongoing. There’s new plans on alternative fuels like methanol and ammonia that continue to evolve,” he told journalists.

    He said he has not heard any government dispute a set of decarbonisation goals agreed in 2023. These include targets to reduce emissions 20-30% on 2008 levels by 2030 and then to reach net zero emissions “by or around, i.e. close to 2050”.

      Dominguez said the 2030 emissions reduction target could be reached, although a goal for shipping to use at least 5% clean fuels by 2030 would be difficult to meet because their cost will remain high until at least the 2030s. The goals agreed in 2023 also included cutting emissions by 70-80% by 2040.

      In October 2025, a decision on a proposed framework of practical measures to achieve the goals, which aims to incentivise shipowners to go green by taxing polluting ships and subsidising cleaner ones, was postponed by a year after a narrow vote by governments.

      Ahead of that vote, the US threatened governments and their officials with sanctions, tariffs and visa restrictions – and President Donald Trump called the framework a “Green New Scam Tax on Shipping”.

      Dominguez said at Friday’s press conference that he had not received any official complaints about the US’s behaviour at last October’s meeting but – without naming names – he called on nations to be “more respectful” at the IMO. He added that he did not think the US would leave the IMO, saying Washington had engaged constructively on the organisation’s budget and plans.

      EU urged to clarify ETS position

      The European Union – along with Brazil and Pacific island nations – pushed hard for the framework to be adopted in October. Some developing countries were concerned that the EU would retain its charges for polluting ships under its emissions trading scheme (ETS), even if the Net Zero Framework was passed, leading to ships travelling to and from the EU being charged twice.

      This was an uncertainty that the US and Saudi Arabia exploited at the meeting to try and win over wavering developing countries. Most African, Asian and Caribbean nations voted for a delay.

      On Friday, Dominguez called on the EU “to clarify their position on the review of the ETS, in order that as we move forward, we actually don’t have two systems that are going to be basically looking for the same the same goal, the same objective.”

      He said he would continue to speak to EU member states, “to maintain the conversations in here, rather than move forward into fragmentation, because that will have a very detrimental effect in shipping”. “That would really create difficulties for operators, that would increase the cost, and everybody’s going to suffer from it,” he added.

      The IMO’s marine environment protection committee, in which governments discuss climate strategy, will meet in April although the Net Zero Framework is not scheduled to be officially discussed until October.

      The post IMO head: Shipping decarbonisation “has started” despite green deal delay appeared first on Climate Home News.

      IMO head: Shipping decarbonisation “has started” despite green deal delay

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