Raphael Portmann
@r_portmann
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climate and atmospheric scientist - climate and agriculture - PhD @ETH - passion for @degrowth_ch
Joined February 2021
Our study on the effect of global-scale forestation and deforestation on global weather patterns was published in @NatureComms last week ( https://t.co/IF9SnFeg2I). If there is one implication I want people to take away from our study (and a range of previous ones) it is this:
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Unser Essay über die Illusion von Grünem Wachstum und die Notwendigkeit von #degrowth wurde von der Schweizerischen Akademie der Geistes- und Sozialwissenschaften @SAGW_CH veröffentlicht. @colognav Danke @degrowth_ch und @LorenzClimate fürs 👍Feedback! https://t.co/X9lmnOql13
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It’s important to note that the climate effects of changes in forest cover are often far more complex than carbon storage alone. Albedo, transpiration, and surface roughness all play a role, with relative importance varying by geography.
Our study on the effect of global-scale forestation and deforestation on global weather patterns was published in @NatureComms last week ( https://t.co/IF9SnFeg2I). If there is one implication I want people to take away from our study (and a range of previous ones) it is this:
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This is a very important study showing the limited climate change mitigation potential of forestation in the global drylands when including the radiative forcing from albedo changes. They also provide a handy tool for forestation planners here:
Limited climate change mitigation potential through forestation of the vast dryland regions https://t.co/pdEDFLSKFW.
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Clarification: Planting trees can offset carbon emissions, but its net effect on global climate also depends on albedo changes. Yet, this kind of offset is questionable, as it is moving carbon from a (longer) geological time scale to a (shorter) biological time scale.
Bottom line: planting trees does NOT offset carbon emissions (e.g. flights). Agricultural soil carbon is also an unreliable ephemeral offset. For now, only geological sequestration deserves credits as an offset, and it is tiny in today's world. #CarbonCredits #CarbonMarket
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And finally, it can't be stressed enough: Forestation should never replace a rapid reduction of fossil fuel emissions. Read more on our study in our Nature Community blog article: https://t.co/1dyEN58GEC or the news article of @usys_ethzh :
lnkd.in
This link will take you to a page that’s not on LinkedIn
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I'm not saying such projects should not be done (many good reasons for forestation!) but please stop claiming they help to mitigate climate change without quantifying climate impacts beyond carbon (in the first place, albedo changes, i.e. changes in darkness of the land surface).
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Stop selling (or buying) carbon credits based on forestation projects in mid and high latitudes before having done a careful analysis of the full climate impact of the project.
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A study in @NatureComms suggests that large-scale forestation projects may alter the Earth’s energy balance, affecting both global atmospheric and ocean circulation patterns. https://t.co/b3Zl1mAim9
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Large-scale forestation may alter the Earth’s energy balance, affecting both global atmospheric and ocean circulation patterns. Modelling study published @NatureComms by @r_portmann @UrsBeyerle @SebastianSchemm @EduardDavin @erichfischer @HertogSteven: https://t.co/1jsIgGvhOY
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"Lovely frisst die Wiese grün". So wirb Swissmilk dafür, dass der Konsum von Milch klimafreundlich sei. Denn grasende Kühe "fördern das CO₂-Bindepotenzial von Schweizer Wiesen". Das stimmt zwar, ist aber nur 3% der Wahrheit:
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Today's #StrikeForFuture focuses on reduction of working hours as a way to take #ClimateAction & catalyze further #SystemsChange. What could this look like from a #degrowth perspective? We evaluate the options in our first Policy Brief: https://t.co/P4VmS6MWoR
#4dayweek #SDG13
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Grossartige Initiative👏🏻 Soeben meine erste Bewertung gemacht.
VelObserver 1.0 ist online! Ab sofort könnt Ihr das Vorzugsroutennetz der Stadt Zürich bewerten. Alle Eure Bewertungen zusammen zeigen, wie velotauglich Zürich ist. Und wir sorgen dafür, dass die Stadt Eure Stimmen hören wird. https://t.co/etk7w3ILfE
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Welche Veloinfrastruktur? Farbe ist keine Veloinfrastruktur und kostet kaum - dann bitte richtige Infrastruktur. Gibts dann auch (3x teurere) Autovignietten für Gemeindestrassen und eine (begrünte) Velobahn zwischen Zürich und Luzern? So wäre ich ev. dabei. Ansonsten: Schnapsidee
Velofahrerinnen und #Velofahrer sollen "die Infrastrukturkosten für den #Veloverkehr" künftig zu einem grossen Teil selber tragen. Das fordert @SVPch-Nationalrat Benjamin #Giezendanner mit einem Vorstoss, den 45 Mitglieder der SVP, FDP und der Mitte mitunterzeichnet haben. (1/4)
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Am Gründungsevent @degrowth_ch bin ich brav maskiert vor Ort... Aber du kannst ganz locker von Zuhause die spannenden Keynotes verfolgen.
🎥We’re live from Kulturpark! Tune in to the livestream & join the conversation using the hashtag #DSCHLaunch. https://t.co/wZgt1PxM7S Today’s speakers: @jksteinberger of @UNIL, Irmi Seidel of @WSL_research, @colognav, Lea Tamberg & @LorenzClimate. 🗣️@akkforreal 📝us your Qs!
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We are looking forward to our Launch Event on Dec. 10! Due to rising COVID cases we have capped access to the venue but there will be a livestream of Part One, so you can follow online. 🥳 Mark your 🗓: https://t.co/wZgt1PxM7S Join the conversation using the hashtag #DSCHLaunch
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What's the justification to cover the COVID-19 crisis (which is bad) every single day prominently in the news but not the climate crisis (which is much worse!)?
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Verkehr ist der Sektor mit den grössten CO2eq Emissionen in der CH. Warum nicht gleich transparent sein und Emissionsszenarien mitliefern? Nachhaltige Mobilität geht anders, effizienter, gesünder, sicherer, und es ist möglich.
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Kein einziges der Verkehrsszenarien scheint kompatibel mit dem 1.5°C Ziel. Selbst im nachhaltigen Szenario nehmen die pkm mit PkWs bis 2050 zu und 15% aller Fahrzeuge sind noch benzinbetrieben. Wollt ihr uns verarschen @UVEK? https://t.co/r8mPsucjjs
@VelobserverZH @KlimaschutzCH
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