#uöäü1sinks
LightNews LightNews
umsonst.bsky.social
We find that in 2023 the Amazon region was, including fires, a net carbon source of 0.01 to 0.17 PgC.

"Reduced vegetation uptake during the extreme 2023 drought turns the Amazon into a weak carbon source"; pure.mpg.de/rest/items/i...

#climate #Amazon #Forest #Earth #uöäü1sinks #CMIP6
April 25, 2025 at 8:13 PM
umsonst.bsky.social
One reason of why the ocean atmosphere coupling is so important:

"A stronger southern hemispheric (SH) westerlies enhance SO upwelling, thus leading to stronger natural CO2 outgassing, with a sensitivity of 0.13 GtC/yr for a 10% increase in SH westerly windstress."

#climate #uöäü1sinks
Frontiers | Southern Ocean circulation’s impact on atmospheric CO2 concentration
In the context of past and present climate change, the Southern Ocean (SO) has been identified as a crucial region modulating the concentration of atmospheri...
www.frontiersin.org
March 22, 2025 at 6:17 PM
umsonst.bsky.social
Our terrestrial biosphere is loosing its resilience towards droughts fast

Important: further declines will be much steeper as we trigger here a non-linear reaction.

#climate #Earth #uöäü1sinks
Jan Umsonst
Our terrestrial biosphere is loosing its resilience towards droughts fast Important: further declines will be much steeper as we trigger here a non-linear reaction. Our course is pure madness as...
www.facebook.com
April 4, 2025 at 4:51 PM
umsonst.bsky.social
Next massive model error gets confirmed: Serious underestimation of reduced carbon uptake due to vegetation compound droughts

The error will develop a non-linear nature as the underlying processes not included in models behave non-linear...

#CMIP6 #CMIP5 #climate #extremeevents #uöäü1sinks
Shows the occurrence of atmospheric (low humidity and high air temperatures) and soil drought conditions "Drought directly limits terrestrial water availability and carbon uptake through low soil moisture (SM) and/or high vapor pressure deficit (VPD) 6,7 , and extreme water stress can substan- tially reduce agricultural production 8,9 and bring about wide- spread vegetation mortality 10,11 . Specifically, drought suppresses photosynthetic assimilation rates by reducing stomatal conduc- tance and related enzyme activity 6,12 and inducing leaf senes- cence and abscission as well 13 , resulting in reduced gross primary productivity (GPP) at the ecosystem scale. When water is limited, compound droughts (CDs) characterized by concurrent low SM and high VPD would cause even greater reductions in GPP than soil drought (low SM) or atmospheric aridity (high VPD) alone 14,15 . Low SM and high VPD tend to occur simultaneously over much of the global land surface, as SM deficits reduce evapotranspiration and increase sensible heat flux, resulting in a drier and warmer atmosphere and a higher VPD, and the high VPD in turn enhances evaporative water loss and accelerates reduction in SM16,17 . " Here on models: CDs are projected to become more frequent and more extreme, which could greatly reduce land carbon sink and compromise climate mitigation efforts 3,14 . However, assessments of past and future changes in CDs largely focus on extreme events from a statistical perspective 4,17,18 without taking into account whether these events cause adverse impacts on the environment. Risks of VCDs have been greatly underestimated as the widely adopted quantile-based approach identifies only 11% of VCDs and 26% of global GPP anomalies due to VCDs. The frequency and intensity of VCDs and their adverse impacts on carbon uptake are projected to increase further, irrespective of whether the CO2 fertilization effect on vegetation growth and photosynthesis is considered or not.
May 4, 2025 at 10:31 AM
umsonst.bsky.social
Another detail on the collapsing terrestrial carbon sink: litter carbon sink weakens

Over 2000–2018, litter C release increased (0.49 ± 0.07 g C m−2 yr−2), while the net litter C sink decreased (−0.10 ± 0.04 g C m−2 yr−2), driven primarily by changing water availability

#climate #uöäü1sinks
Water Availability Weakens the Forest Litter Carbon Sink
The increasing rate of litter C release rose from 0.37 to 0.66 g C m−2 yr−2 as water availability transitioned from extreme to moderate The decreasing rate of the net litter C sink intensified fr...
agupubs.onlinelibrary.wiley.com
February 15, 2026 at 8:27 PM
umsonst.bsky.social
If emissions from fires are included the Arctic–Boreal Zone is no longer a carbon sink

As fires will increase exponentially as we see it the last years to happen...

#climate #uöäü1sinks #Earth
Wildfires offset the increasing but spatially heterogeneous Arctic–boreal CO2 uptake - Nature Climate Change
How the carbon stocks of the Arctic–Boreal Zone change with warming is not well understood. Here the authors show that wildfires and large regional differences in net carbon fluxes offset the overall ...
www.nature.com
April 6, 2025 at 12:18 PM
umsonst.bsky.social
The ocean carbon sink is highly variable...

"There is also evidence of an increase in the magnitude of the seasonal cycle over time" of the ocean carbon uptake on a regional level. Increasing variability of ever more components of the Earth system you don't want to have!

#climate #uöäü1sinks
Nice example of how extreme values can get over large ocean areas - e.g. the La Nina in (e) producing exceptional high levels of carbon rich waters a the surface.
April 24, 2025 at 9:16 PM
umsonst.bsky.social
Terrestrial sequestration of carbon has mitigated ≈30% of anthropogenic carbon emissions.

we found that ≈35 ± 14 gigatons of carbon (GtC) have been sequestered on land between 1992 and 2019, whereas live biomass changed by ≈1 ± 7 GtC.

#Earth #climate #uöäü1sinks
Recent gains in global terrestrial carbon stocks are mostly stored in nonliving pools
Terrestrial sequestration of carbon has mitigated ≈30% of anthropogenic carbon emissions. However, its distribution across different pools, live or dead biomass and soil and sedimentary organic carbon...
www.science.org
April 9, 2025 at 6:34 PM
umsonst.bsky.social
Loss of resilience in the Amazon from 2000s till 2016 - much worse now as we have also here a non linear self-reinforcing development!

"Overall, most (76.2%) of the grid cells show increasing AR(1) values from the early 2000s onwards and hence, loss of resilience"

#climate #uöäü1sinks
Graphs showing the loss in resilience over the Amazon rainforest. Red pixels extent all the way into the northern parts of the forest. a, A map of the Kendall τ values of individual grid cells from 2003. b, Histogram of the Kendall τ values for the Amazon rainforest, considering data from 2003 onwards. Of the grid cells, 76.2% have a positive Kendall τ value from 2003 onwards and 77.8% have this for the full time series. c, Mean VOD AR(1) time series (solid line) along with ±1 s.d. (dotted lines) created from grid cells that have BL fraction ≥80% in the Amazon basin and also contain no human land use (main text and Methods). The full AR(1) time series from 1991 (grey) has a Kendall τ value of 0.589 (P = 0.006) and from 2003 (black), a value of 0.913 (P < 0.001). Note that the AR(1) values are plotted at the end of each 5-yr sliding window. Country and Amazon basin outlines produced as described in Fig. 1.
January 4, 2025 at 2:36 PM
umsonst.bsky.social
GW has now serious impacts on the terrestrial water cycle. part or collapse of the terrestrial carbon sink...

"global terrestrial water storage (TWS), excluding ice sheets and glaciers, declined rapidly between May 2014 and March 2016. By 2023, it had not yet recovered"

#climate #uöäü1sinks
An Abrupt Decline in Global Terrestrial Water Storage and Its Relationship with Sea Level Change - Surveys in Geophysics
As observed by the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow On (GRACE-FO) missions, global terrestrial water storage (TWS), excluding ice sheets and glaciers, declined rapidly ...
link.springer.com
November 26, 2024 at 2:42 PM
umsonst.bsky.social
Upper ocean vertical temperature gradient increase CO2 uptake - Atlantic 50°N-50°S by 7%.

Maybe one of the reasons for the decline of the ocean carbon sink in recent years?

"Enhanced ocean CO2 uptake due to near-surface temperature gradients"; www.nature.com/articles/s41...

#climate #uöäü1sinks
Enhanced ocean CO2 uptake due to near-surface temperature gradients - Nature Geoscience
Accounting for near-surface temperature gradients leads to estimates for annual CO2 uptake in the North Atlantic that are 7% higher, based on a comparison of eddy covariance and bulk CO2 measurements,...
www.nature.com
November 5, 2024 at 5:27 AM
umsonst.bsky.social
Preprint - waited here for a study:

In 2023 we had an unexpected weak carbon uptake by the oceans despite an El Nino (10% less then expected)

reason: higher sea surface temperatures

While we still increase our emissions both carbon sinks are now in decline - just WOW!

#climate #uöäü1sinks
In 2023, sea-surface temperatures (SST) reached record highs. Based on historical responses, this SST anomaly would suggest an increased oceanic CO2 uptake (-0.11±0.03 PgC yr-1). In contrast, our observation-based estimates reveal that the global non-polar ocean absorbed about 10% less carbon than expected (+0.16±0.28 PgC yr-1). This weakening occurred despite reduced CO2 outgassing in the tropics associated with El Niño. Hence, the decline in CO2 uptake in 2023 materialised entirely in the extratropics, driven primarily by elevated SSTs in the Northern Hemisphere. Two ocean biogeochemical models demonstrate that in the subtropical North Atlantic the thermally-induced reduction in CO2 uptake was strongly mitigated by the depletion of dissolved inorganic carbon in the surface mixed layer. Such negative feedbacks cause an overall muted response of the ocean carbon sink to the record high SSTs, but this resilience may not persist under long-term warming or more severe SST extremes. "Unexpected decline of the ocean carbon sink under record-high sea surface temperatures in 2023"; https://assets-eu.researchsquare.com/files/rs-5198321/v1_covered_538b07ae-65a0-487d-b6b3-662f7c322ec0.pdf?c=1731428416 Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC) are based on land-use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based fCO2-products. The terrestrial CO2 sink (SLAND) is estimated with dynamic global vegetation models. Additional lines of evidence on land and ocean sinks are provided by atmospheric inversions, atmospheric oxygen measurements and Earth System Models. The sum of all sources and sinks results in the carbon budget imbalance (BIM), a measure of imperfect data and incomplete understanding of the169 contemporary carbon cycle. All uncertainties are reported as ±1σ. For the year 2023, EFOS increased by 1.3% relative to 2022, with fossil emissions at 10.1 ± 0.5 GtC yr-1 (10.3 ±171 0.5 GtC yr-1 when the cement carbonation sink is not included), ELUC was 1.0 ± 0.7 GtC yr-1, for a total anthropogenic CO2 emission (including the cement carbonation sink) of 11.1 ± 0.9 GtC yr-1 (40.6 ± 3.2 GtCO2 yr-1). Also, for 2023, GATM was 5.9 ± 0.2 GtC yr-1 (2.79 ± 0.1 ppm yr-1), SOCEAN was 2.9 ± 0.4 GtC yr-1 and SLAND was 2.3 ± 1.0 GtC yr-1, with a near zero BIM (-0.02 GtC yr-1). The global atmospheric CO2 concentration averaged over 2023 reached 419.3 ± 0.1 ppm. Preliminary data for 2024, suggest an increase in EFOS relative to 2023 of +0.8% (-0.3% to 1.9%) globally, and atmospheric CO2 concentration increased by 2.8 ppm reaching177 422.5 ppm, 52% above pre-industrial level (around 278 ppm in 1750). Source: Global Carbon budget 2024 https://essd.copernicus.org/preprints/essd-2024-519/essd-2024-519.pdf
November 20, 2024 at 9:03 PM
umsonst.bsky.social
This one I had been searching for - the impacts are coming closer...

we further show that enhanced physically-driven air-sea gas exchanges in the polar Southern Ocean strongly drove CO2 outgassing towards the end of the last deglaciation.

#climate #uöäü1sinks
Contributions of biological and physical dynamics to deglacial CO2 release from the polar Southern Ocean - Nature Communications
The authors use mid-latitude deep-water properties to infer carbon cycle changes in the polar Southern Ocean. They find biological and physical dynamics contributed to CO2 release from the surface pol...
doi.org
March 22, 2025 at 6:59 PM
umsonst.bsky.social
Both sinks are in the process to collapse (terrestrial) or weaken (oceans), while we still increase our emissions with the result of another CO2 increase by 2.9ppm from 2023-2024...

Good thing methane trend weakened a lot in 2024 - wonder why?

#climate #uöäü1sinks
copernicusecmwf.bsky.social Copernicus ECMWF @copernicusecmwf.bsky.social · Jan 14
📈 In 2024, greenhouse gases reached their highest annual levels ever recorded in the atmosphere.
🌁 Carbon dioxide concentrations reached 422 ppm, 2.9 ppm higher than in 2023, & methane 1897 ppb, 3 ppb higher.
▶️ All details, charts and data in the
#GCH2024 report: bit.ly/40kQpcz
January 14, 2025 at 9:34 PM