Achim Dohmen
achimdohmen.bsky.social
Achim Dohmen
@achimdohmen.bsky.social
Skeptiker, Suchmaschinen-Autodidakt, trotz absolutem Gehör nur mittelmäßiger Zuhörer
Reposted by Achim Dohmen
Green hydrogen as a hedge against gas price shocks? Puh-lease. European gas prices exceeded a €5/kg hydrogen-price-equivalent for only 141 days after Russia's invasion of Ukraine, and a €10/kg price for just 13 days. You don't pay €5-10/kg for 25 years for fear of a spike lasting a few weeks.
November 5, 2025 at 7:28 PM
Reposted by Achim Dohmen
Why did GHG emissions rise?

50% of the increase was from land-use change, primarily due to more fires during El Niño. We expect this to drop in 2025. LUC is also very uncertain.

All other main regions, except EU27, with rising emissions in 2024.

2/
November 5, 2025 at 8:24 AM
Vielleicht beschreibt dieser Artikel in der NYT die Stimmung derer, die eine Cancel Culture und beschränkte Meinungsfreiheit sehen:
www.nytimes.com/2025/08/21/o...
Opinion | The Rise of Right-Wing Nihilism
www.nytimes.com
August 23, 2025 at 6:48 AM
Reposted by Achim Dohmen
Our new paper updating key metrics in the IPCC is now out, and the news is grim:

⬆️ Human induced warming now at 1.36C
⬆️ Rate of warming now 0.27C / decade
⬆️ Sharp increase in Earth's energy imbalance
⬇️ Remaining 1.5C carbon budget only 130 GtCO2

essd.copernicus.org/...
Indicators of Global Climate Change 2024: annual update of key indicators of the state of the climate system and human influence
Abstract. In a rapidly changing climate, evidence-based decision-making benefits from up-to-date and timely information. Here we compile monitoring datasets (published at https://doi.org/10.5281/zenodo.15639576; Smith et al., 2025a) to produce updated estimates for key indicators of the state of the climate system: net emissions of greenhouse gases and short-lived climate forcers, greenhouse gas concentrations, radiative forcing, the Earth's energy imbalance, surface temperature changes, warming attributed to human activities, the remaining carbon budget, and estimates of global temperature extremes. This year, we additionally include indicators for sea-level rise and land precipitation change. We follow methods as closely as possible to those used in the IPCC Sixth Assessment Report (AR6) Working Group One report. The indicators show that human activities are increasing the Earth's energy imbalance and driving faster sea-level rise compared to the AR6 assessment. For the 2015–2024 decade average, observed warming relative to 1850–1900 was 1.24 [1.11 to 1.35] °C, of which 1.22 [1.0 to 1.5] °C was human-induced. The 2024-observed best estimate of global surface temperature (1.52 °C) is well above the best estimate of human-caused warming (1.36 °C). However, the 2024 observed warming can still be regarded as a typical year, considering the human-induced warming level and the state of internal variability associated with the phase of El Niño and Atlantic variability. Human-induced warming has been increasing at a rate that is unprecedented in the instrumental record, reaching 0.27 [0.2–0.4] °C per decade over 2015–2024. This high rate of warming is caused by a combination of greenhouse gas emissions being at an all-time high of 53.6±5.2 Gt CO2e yr−1 over the last decade (2014–2023), as well as reductions in the strength of aerosol cooling. Despite this, there is evidence that the rate of increase in CO2 emissions over the last decade has slowed compared to the 2000s, and depending on societal choices, a continued series of these annual updates over the critical 2020s decade could track decreases or increases in the rate of the climatic changes presented here.
essd.copernicus.org
June 18, 2025 at 11:10 PM
Reposted by Achim Dohmen
Updated fossil CO2 emission estimates from @robbieandrew.bsky.social

Based on the latest data, we estimate fossil CO2 emissions went up 0.9% in 2024.

Listen to his presentation here (starting about 8:55): cicero.oslo.no/no/arrangeme...

1/
May 6, 2025 at 7:09 AM
Reposted by Achim Dohmen
Total CO2 emissions are still rising.

It is necessary to reduce emissions drastically to zero to stop the temperature increasing. To keep below 1.5C is no longer feasible, but that does not mean give up, but try harder.

7/7
May 6, 2025 at 7:09 AM
Reposted by Achim Dohmen
EU:
* Long-term decline of coal: successful EU policy
* Decline in natural gas in recent years: Energy prices, Russian aggression
* Nuclear power turmoil (France, Germany, Belgium)
* Hydropower swings: droughts
*Strong renewables growth

5/
May 6, 2025 at 7:09 AM
Reposted by Achim Dohmen
Those were the top-4 fossil CO2 emitters in terms of aggregated emissions.

Each country has its own story... Just because they emit less, does not mean they are not important!

6/
May 6, 2025 at 7:09 AM
Reposted by Achim Dohmen
This chart is incredible, have used it myself in the past. www.ft.com/content/f867...
May 12, 2025 at 8:50 AM
Reposted by Achim Dohmen
Over the years, quite a few of you have asked me explain the #HydrogenSoufflé thing specifically to Germans, who seem weirdly (and expensively) enamoured of the #HydrogenEconomy. So here's me, doing my best... in German. And no it's not AI, it really is me :-) www.youtube.com/watch?v=KJo3...
Milliardengrab Wasserstoff? 😤 Wer BEZAHLT das!? Michael Liebreich | H2-Strategie | Geladen Podcast
YouTube video by Geladen Batteriepodcast
www.youtube.com
February 9, 2025 at 11:06 AM
Reposted by Achim Dohmen
We talk a lot about 1.5°C, but we should talk more about net zero CO2 emissions.

It is much more actionable (www.nature.com/articles/nge...) & also gives the approximate temperature level:
* 2036 = 1.5°C
* 2050 = 1.7°C
* 2080 = 2.0°C

When will the world hit net zero CO2 emissions?
November 28, 2024 at 10:13 AM