La Wallonie face aux changements climatiques : personne ne sera épargné, les cartes des risques pour préparer l’action - RTBF Actus Toutes les cartes sont désormais accessibles ici, sur le Portail Climat. Vous, et moi pouvons le consulter à l’envi....

Quels sont les ménages les plus exposés au changement climatique en Région Wallonne ?

👉 Article très fouillé et très complet de Daphné Van Ossel (RTBF). Merci pour ce travail !

@xavierfettweis.bsky.social @universitedeliege.bsky.social @rtbf-info.be

www.rtbf.be/article/la-w...

Positions remain open! Both PhD and postdoctoral opportunities are available on scientific foundation models. An additional position is also available on AI for regional climate models (jointly with @xavierfettweis.bsky.social). Do not hesitate to apply!

Extreme rainfall is set to become more intense and more frequent by 2100 in Belgium This is the future projection of a study conducted by climatologists and hydrogeologists at the University of Liège using their regional climate MAR model.

Major publication from my PhD student Josip Brajkovic in the Journal of Hydrology: Regional Studies. Every degree counts! For every 1°C "gains," we'll see an increase in extreme precipitation intensity of +7% and a frequency of /2.
@universitedeliege.bsky.social
www.news.uliege.be/cms/c_204299...

Brice Noël, recipient of the Arne Richter Award from the European Geosciences Union (EGU) He received this award for his research on the melting of glaciers and polar ice sheets

Congrats to Brice Noël, climatologist, winner of the 2025 Arne Richter Award from the @egu.eu 👏 His cutting-edge work on glacier melt, polar climate modeling, and sea-level rise is shaping global climate science. @xavierfettweis.bsky.social
www.sciences.uliege.be/cms/c_134761...

Greenland Real-time state of the 2024-2025 Greenland ice sheet surface mass balance as simulated by the regional climate model MARv3.14 Surface Mass Balance (SMB) = snowfall + rainfall - meltwater runoff - sublimation/evaporation Fig 0: Time series of the anomaly of cumulated Greenland ice sheet (GrIS) Surface Mass Balance (SMB) in GT simulated by the regional climate model MAR (version 3.14, run at a resolution of 10km) forced by the ERA5 reanalysis (till today's date - 7 days) and by the Global Forecast System (GFS) model (today's date - 7 days to the today's date +7 days in forecast mode). The gray shading area represents the 1981-2010 standard deviation around the 1981-2010 average. This plot can be put in parallel with the current state of the Arctic sea ice extent. Negative anomaly means a sea level rise contribution. Finally, the equivalent of this figure but for the other Arctic ice caps is available here. Fig 1: a) Time series of the cumulated Greenland ice sheet (GrIS) Surface Mass Balance (SMB) in GT simulated by the regional climate model MAR (version 3.14.0 run at a resolution of 10km) forced by the ERA5 reanalysis and by the Global Forecast System (GFS) model (today's date - 5 days to the today's date +7 days in forecast mode) since 1 Sep 2011 (in green), and 1 Sep 2019 (in red). The 1981-2010 mean simulated by MARv3.14 forced by ERA5 is also plotted in black. The 0-24h forecast of each day from the GFS run of 00hTU has been used to build the time series from the end of ERA5 to now. Finally, the gray shading area represents the standard deviation around the 1981-2010 average (in black). b) Same as a) but for the daily SMB in GT/day. The absolute maximum/minimum SMB rate of each day is plotted in blue. c) Daily mean GrIS near-surface temperature (TAS) simulated by MAR. The absolute maximum temperature of each day is plotted in blue. d) Time series of the North Atlantic Oscillation (NAO) index from NOAA e) Time series of the Greenland ice sheet Blocking Index (GBI) from NOAA. Fig 2a: Left) Cumulated SMB (in mm) from the 1 Sep 2022 to the today's date as simulated by MARv3.14 forced by ERA5/GFS. Right) Same as Left) but in respect to the 1981-2010 ERA5 forced average from the 1 Sep to the today's date. The anomalies lower than the 1981-2010 interannual variability are hatched. Fig 2b: Same as Fig 2a but for snowfall. Fig 2c: Same as Fig 2a but for run-off. Fig 3: Time series of a) the daily mean GrIS Run-off (in GT/day), b) production of meltwater (in GT/day), c) daily mean GrIS incomming long/shortwave radiation (in W/m²)), d) bare ice extent (i.e. area where the surface density is > 900 kg/m^3 in % of the ice sheet surface) and e) daily mean GrIS surface albedo simulated by MARv3.14 forced by ERA5/GFS (1981-2025). Fig 4: Left) Number of melt days ( (i.e. when the daily meltwater production > 5 mmWE/day) from the 1 May 2025 to the today's date. Right) Same as Left) but in respect to the 1981-2010 average from 1 May to 31 Aug. Fig 5a: Left) Melt extent as simulated by MARv3.14 forced by ERA5 and forecasted forced by GFS. Daily meltwater production > 5 mmWE/day (resp. > 1mm/day in dash) is used here as melt threshold in MARv3.14. This melt threshold has been chosen independently of the NSIDC data (see Fig 5b) and the ice mask used here includes both the small perifical ice caps and the main ice sheet, explaining why both estimations do not generally compare. Right) Same as left but for the bare ice extent i.e. the area where the surface density > 900kg/m3. Fig 5b: Melt extent as derived from satellite data (Credit: NSIDC/Thomas Mote). The melt extent shown on this figure can not be directly compared with the melt extent from MAR (Fig 5a) using a different ice sheet mask and a melt threshold. Fig 6: Greenland bloking index (GBI) from NCEP-NCARv1 in red and from the Global Forecast System (GFS) based forcasting in dashed red. According to Hanna et al. (2013), the GBI is defined as the 500hPa geopotential height (Z500) area averaged over 60-80°N, 280-340°E. Fig 7: Idem as Fig. 6 but for 700hPa temperature (T700) averaged over 60-80°N, 280-340°E. Fig 8: Left) Anomaly of surface albedo in respect to the 1981-2010 average over the same day (today's date). Righ) Anomaly of the JJA mean surface albedo in respect to the 1981-2010 average from 1 April to the today's date. Fig 9: Same as Fig. 8 but for the near-surface temperature (~2m) as simulated by MARv3.14 forced by ERA5/GFS. Fig 10: Same as Fig. 9 but for the incoming shortwave radiation (in W/m²) as simulated by MARv3.14 forced by ERA5/GFS. Interesting links: 1. Greenland Ice sheet Today: melt extent (NSIDC) 2. Greenland Ice sheet Polar Portal (DMI,DTU,GEUS) 3. Total Greenland ice sheet mass balance derived from the satellite GRACE data (NASA) 3. MARv3.14 outputs forced by ERA5 including the realtime 2024-2025 estimate are available on http://phypc15.geo.ulg.ac.be/fettweis/MARv3.14/Greenland/ERA5-10km-daily/ 4. Reference of these MAR simulations: Tedesco, M. and Fettweis, X.: Unprecedented atmospheric conditions (1948–2019) drive the 2019 exceptional melting season over the Greenland ice sheet, The Cryosphere, 14, 1209–1223, https://doi.org/10.5194/tc-14-1209-2020, 2020. Contact: Xavier Fettweis These forecasts are only provided for information in the aim of following the 2024-2025 melting season over Greenland in real time; ULiège can not be held responsible for any use beyond this scope. Total ice sheet mass balance (TMB) = SMB - icebergs discharge ~ 400 - 400 = 0 GT/yr Source of this figure: Nowicki, S. M. J., Payne, A., Larour, E., Seroussi, H., Goelzer, H., Lipscomb, W., Gregory, J., Abe-Ouchi, A., and Shepherd, A.: Ice Sheet Model Intercomparison Project (ISMIP6) contribution to CMIP6, Geosci. Model Dev., 9, 4521–4545, https://doi.org/10.5194/gmd-9-4521-2016, 2016.

Data: 4-days forecast by the MAR model forced by GFS

www.climato.uliege.be/cms/c_565266...

The melting season over the Greenland ice sheet is starting with likely one of the highest melt event for a month of May. The omega blocking responsible of the drought over Europe advectes very warm air masses along it west size towards the Greenland ice sheet.

A study, using our climate model MAR, lead by my colleague Brice Noel (FNRS) and published in Nature Communications, links the rapid mass loss of Patagonian glaciers to a poleward shift of subtropical high-pressure systems.

www.sciences.uliege.be/cms/c_134669...

The polar vortex is "living" its final hours. Its disorganization usually occurs at mid-spring. So, in short, the high pressure system, currently over Western Europe, is not about to move. This suggests a drought in the coming weeks and South => North (heat) or N => S (late frosts) circulations.

Picture of a measurement site on the Greenland Ice Sheet. In the foreground is a fixed‐wing uncrewed aerial system (UAS), looking like a small, light plane with a wing span of 3 m. The UAS is prepared for take-off on a launching system with a high pressure flask that is filled with air through a connected compressor. In the background are white, heated measurement cabin and a turbulence measurement system (eddy covariance) that is connected with a thick bundle of cables to the cabin.

📚 New paper alert! 🧵
agupubs.onlinelibrary.wiley.com/doi/10.1029/...

🧪 We present a unique dataset of 465 (!) in situ measurements of the #water_isotopes in vapor up to 1500m above the #Greenland Ice Sheet.

🌍 We demonstrate the use of water isotope profiles to reveal gaps in climate model physics.

Les glaciers déclinent partout autour du globe, perdant l’équivalent de trois piscines olympiques par seconde Les Alpes et les Pyrénées figurent parmi les zones les plus touchées, s’étant délestés d’environ 40 % de leur masse en vingt ans, selon une étude parue mercredi dans « Nature ».

Sous l’effet du réchauffement climatique, les glaciers ont perdu 6 500 milliards de tonnes de glace entre 2000 et 2023, soit l’équivalent de trois piscines olympiques par seconde. Les Alpes et les Pyrénées, les zones les plus touchées, ont vu 40 % de leur glace fondre www.lemonde.fr/planete/arti...

Repeat photography showing the accelerated retreat of Ossoue Glacier in the Pyrenees between 2000 and 2023, with extinction planned before 2030.

Ossoue Glacier (Vignemale, Pyrénées)
2000 | 2023

Will you be able to explain to your children the cause of this disappearance (planned for before 2030) ⁉️

Because none of this happened naturally... ⛽️🔥

📷 Pierre René (Association Moraine)

Arctic set to undergo irreversible damage as hopes of hitting the 1.5C Paris target fade The Arctic is set to undergo dramatic and irreversible changes in the coming years if global warming reaches 2.7°C above pre-industrial levels, ...

What happens in the Arctic doesn't stay in the Arctic. It affects you.
www.intellinews.com/arctic-set-t...

The melting season in Svalbard usually starts in June. This year, it has been started in February!

Data: MAR model output on 02 February 2025

Bel article contrant les affirmations erronées de Trump sur le climat. C'est un exercice qui prend un peu de temps mais ça doit se faire.

factuel.afp.com/doc.afp.com....

An aerial view of a South Greenland glacier from a commercial flight. The top third of the image is the thick while Greenland ice sheet with a few grayish rock peaks protruding. In the middle of the picture, coastal mountains and glacier drainages are visible, and in the lower right, blue ocean dotted with dozens of white icebergs.

Eine neue Studie mit ersten detaillierten Messungen von Gletscherspalten zeigt das Grönland's Eiskappe wahrscheinlich schneller schmilzt als erwartet. insideclimatenews.org/news/0302202...

Recent global temperature surge intensified by record-low planetary albedo In 2023, the global mean temperature soared to almost 1.5 kelvin above the preindustrial level, surpassing the previous record by about 0.17 kelvin. Previous best-guess estimates of known drivers, inc...

Voici un bel article à lire à ce propos: www.science.org/doi/10.1126/...

Le Groenland - Climat, écologie, société - CNRS Editions Le Groenland - Climat, écologie, société (EAN13 : 9782271081704) édité par CNRS Editions - Jamais le Groenland n’a suscité autant d’intérêt qu’aujourd’hui. Couverte à 85 % de glace, la plus

En 2015, nous avions publié ce livre croisant de multiples perspectives et sources de connaissances, y compris de Groenlandais, 🇬🇱, qui démarrait par : "jamais le Groenland n'a suscité autant d'intérêt qu'aujourd'hui" 🤔...

www.cnrseditions.fr/catalogue/ec...

Le président Donald Trump quitte l’accord de Paris : est-ce foutu pour la planète ? Parmi la pluie de décrets que Donald Trump a signée dès le premier jour de son investiture comme 47e président des...

This article sums up quite well what I think (as well as my colleague Prof. Jean-Pascal van Ypersele) about President Trump's recent decision to withdraw from the Paris Agreement. For me, the biggest risk in the medium term is mainly his Minister of Efficiency...
www.rtbf.be/article/le-p...