Zeke Hausfather
@hausfath.bsky.social
"A tireless chronicler and commentator on all things climate" -NYTimes.
Climate research lead @stripe, writer @CarbonBrief, scientist @BerkeleyEarth, IPCC/NCA5 author.
Substack: https://theclimatebrink.substack.com/
Twitter: @hausfath
Climate research lead @stripe, writer @CarbonBrief, scientist @BerkeleyEarth, IPCC/NCA5 author.
Substack: https://theclimatebrink.substack.com/
Twitter: @hausfath
Forster and Rahmstorf doesn’t have that table in it, and they do not claim we can extrapolate the current rate of warming later in the century.
November 15, 2025 at 9:47 PM
Forster and Rahmstorf doesn’t have that table in it, and they do not claim we can extrapolate the current rate of warming later in the century.
These estimates build on a broader literature of current policy estimates that I reviewed in a recent paper in Dialogues on Climate Change earlier this year: journals.sagepub.com...
November 14, 2025 at 6:52 PM
These estimates build on a broader literature of current policy estimates that I reviewed in a recent paper in Dialogues on Climate Change earlier this year: journals.sagepub.com...
These six studies show a central estimate of warming from 2.4C to 2.9C, with large climate system uncertainties due to climate sensitivity and carbon cycle feedbacks; its possible that current policy warming could be as high as 4C if we roll 6s on the proverbial climate dice.
November 14, 2025 at 6:52 PM
These six studies show a central estimate of warming from 2.4C to 2.9C, with large climate system uncertainties due to climate sensitivity and carbon cycle feedbacks; its possible that current policy warming could be as high as 4C if we roll 6s on the proverbial climate dice.
Small typo here: it’s falling land use emissions that have counterbalanced rising fossil emissions!
November 13, 2025 at 7:07 AM
Small typo here: it’s falling land use emissions that have counterbalanced rising fossil emissions!
Sorry, that’s what I get from not proofreading the thread. The Carbon brief piece has it right!
November 13, 2025 at 7:07 AM
Sorry, that’s what I get from not proofreading the thread. The Carbon brief piece has it right!
For more details, see my @carbonbrief.org article with Global Carbon Budget lead @pfriedling.bsky.social: www.carbonbrief.org/...
And the new Global Carbon Budget paper: essd.copernicus.org/...
And the new Global Carbon Budget paper: essd.copernicus.org/...
Analysis: Fossil-fuel CO2 emissions to set new record in 2025, as land sink ‘recovers’ - Carbon Brief
Carbon dioxide (CO2) emissions from fossil fuels and cement will rise around 1.1% in 2025,...
www.carbonbrief.org
November 13, 2025 at 3:26 AM
For more details, see my @carbonbrief.org article with Global Carbon Budget lead @pfriedling.bsky.social: www.carbonbrief.org/...
And the new Global Carbon Budget paper: essd.copernicus.org/...
And the new Global Carbon Budget paper: essd.copernicus.org/...
This amounts to a nearly 20% reduction in the efficacy of current global carbon sinks – that is, both the land and ocean – and a 15% reduction compared to how large they would be without the effects of climate change, leading to an increase of atmospheric CO2 of more than 8ppm since 1960.
November 13, 2025 at 3:26 AM
This amounts to a nearly 20% reduction in the efficacy of current global carbon sinks – that is, both the land and ocean – and a 15% reduction compared to how large they would be without the effects of climate change, leading to an increase of atmospheric CO2 of more than 8ppm since 1960.
A new Nature paper accompanying the Global Carbon Budget finds that the land and ocean sinks are 25% smaller and 7% smaller, respectively, than they would have been without the effects of climate change over 2015-24:
Emerging climate impact on carbon sinks in a consolidated carbon budget | Nature
Despite the adoption of the Paris Agreement ten years ago, fossil CO2 emissions continue to rise, pushing atmospheric CO2 levels to 423 ppm in 2024 and driving human-induced warming to 1.36°C, within years of breaching the 1.5°C limit 1,2. Accurate reporting of anthropogenic and natural CO2 sources and sinks is a prerequisite to tracking the effectiveness of climate policy and detecting carbon sink responses to climate change. Yet notable mismatches between reported emissions and sinks have so far prevented confident interpretation of their trends and drivers 1. Here, we present and integrate recent advances in observations and process understanding to address some long-standing issues in the global carbon budget estimates. We show that the magnitude of the natural land sink is substantially smaller than previously estimated, while net emissions from anthropogenic land-use change are revised upwards 1. The ocean sink is 15% larger than the land sink, consistent with new evidence from oceanic and atmospheric observations 3,4. Climate change reduces the efficiency of the sinks, particularly on land, contributing 8.3 ± 1.4 ppm to the atmospheric CO2 increase since 1960. The combined effects of climate change and deforestation turn Southeast Asian and large parts of South American tropical forests from CO2 sinks to sources. This underscores the need to halt deforestation and limit warming to prevent further loss of carbon stored on land. Improved confidence in assessments of CO2 sources and sinks is fundamental for effective climate policy.
www.nature.com
November 13, 2025 at 3:26 AM
A new Nature paper accompanying the Global Carbon Budget finds that the land and ocean sinks are 25% smaller and 7% smaller, respectively, than they would have been without the effects of climate change over 2015-24:
After an usually weak land carbon sink in 2023, there were articles about its potential collapse. The truth is more complicated; while there is no impending collapse there is growing evidence of a long-term weakening of both the land and ocean carbon sinks due to human activity.
November 13, 2025 at 3:26 AM
After an usually weak land carbon sink in 2023, there were articles about its potential collapse. The truth is more complicated; while there is no impending collapse there is growing evidence of a long-term weakening of both the land and ocean carbon sinks due to human activity.
The atmosphere continues to accumulate the bulk of human CO2 emissions, with about 49% going into the atmosphere on average over the past decade. Atmospheric CO2 is expected to increase by around 2.3ppm, well below the record-setting rise of 3.7ppm in 2024.
November 13, 2025 at 3:26 AM
The atmosphere continues to accumulate the bulk of human CO2 emissions, with about 49% going into the atmosphere on average over the past decade. Atmospheric CO2 is expected to increase by around 2.3ppm, well below the record-setting rise of 3.7ppm in 2024.
The Global Carbon Budget provides estimates of both emissions and sinks (where the CO2 we emit goes). The sum of emissions should equal the sum of sinks, but because they are measured separately using different approaches they don't always completely add up:
November 13, 2025 at 3:26 AM
The Global Carbon Budget provides estimates of both emissions and sinks (where the CO2 we emit goes). The sum of emissions should equal the sum of sinks, but because they are measured separately using different approaches they don't always completely add up:
Coal, oil, gas, and cement all contributed more or less equally to the rise in emissions in 2025:
November 13, 2025 at 3:26 AM
Coal, oil, gas, and cement all contributed more or less equally to the rise in emissions in 2025:
Coal still represents the plurality of global emissions, followed by oil and natural gas:
November 13, 2025 at 3:25 AM
Coal still represents the plurality of global emissions, followed by oil and natural gas:
While policies enacted by the current US administration may increase CO2 emissions going forward, their impact on national emissions levels in 2025 were likely relatively modest compared to other factors.
November 13, 2025 at 3:25 AM
While policies enacted by the current US administration may increase CO2 emissions going forward, their impact on national emissions levels in 2025 were likely relatively modest compared to other factors.
Why did US emissions increase? Three factors: a colder start to the year, which led to greater heating requirements, higher gas prices, which led to more coal being used in power generation (up 7.5%!), as well as an increase in total demand for electricity.
November 13, 2025 at 3:25 AM
Why did US emissions increase? Three factors: a colder start to the year, which led to greater heating requirements, higher gas prices, which led to more coal being used in power generation (up 7.5%!), as well as an increase in total demand for electricity.
Chinese and EU emissions were more or less flat in 2025 (Chinese emissions may have actually declined slightly, but its too early to know for sure: www.carbonbrief.org/...).
US emissions increases drove much of the increase in global emissions in 2025.
US emissions increases drove much of the increase in global emissions in 2025.
November 13, 2025 at 3:25 AM
Chinese and EU emissions were more or less flat in 2025 (Chinese emissions may have actually declined slightly, but its too early to know for sure: www.carbonbrief.org/...).
US emissions increases drove much of the increase in global emissions in 2025.
US emissions increases drove much of the increase in global emissions in 2025.
China is the largest global emitter at 32% of global emissions, followed by the US at 13%, India at 8%, and the EU at 6%.
November 13, 2025 at 3:25 AM
China is the largest global emitter at 32% of global emissions, followed by the US at 13%, India at 8%, and the EU at 6%.
Falling fossil emissions have largely counterbalanced rising land use emissions over the past decade, leading to a plateau in global emissions. However, land use emissions remain quite uncertain, and gains made recently in reducing deforestation must be maintained.
November 13, 2025 at 3:25 AM
Falling fossil emissions have largely counterbalanced rising land use emissions over the past decade, leading to a plateau in global emissions. However, land use emissions remain quite uncertain, and gains made recently in reducing deforestation must be maintained.
Late to the party, but this might be helpful (particularly the second half): www.carbonbrief.org/explainer-ho...
Explainer: How human-caused aerosols are ‘masking’ global warming - Carbon Brief
Carbon Brief unpacks the climate effects of aerosols, how their emissions have changed over time and how they could impact the pace of future warming
www.carbonbrief.org
November 12, 2025 at 9:31 PM
Late to the party, but this might be helpful (particularly the second half): www.carbonbrief.org/explainer-ho...
2.7C by 2100 under current policies, albeit with a fair bit of uncertainty.
Thankfully there is no plausible world where we get to 2.9C by 2050.
Thankfully there is no plausible world where we get to 2.9C by 2050.
November 5, 2025 at 5:47 PM
2.7C by 2100 under current policies, albeit with a fair bit of uncertainty.
Thankfully there is no plausible world where we get to 2.9C by 2050.
Thankfully there is no plausible world where we get to 2.9C by 2050.