"One of the planet’s most vital #CarbonSinks i.e. SOUTHERN OCEAN (SO) (absorbs ~40% of C) is revealing its secrets as tiny organisms in the SO play an outsized role in moderating Earth’s #climate."
Details from the recent research are discussed in a🧵⬇️ 1/8
"Based on 107 independent observations of the seasonal cycle from 63 #biogeochemical profiling floats, new study conducted by scientists from #NOAA & University of Hawai'i provide the basin-scale estimate of distinct biogenic #CarbonPool production at Southern Ocean." 2/8
Researchers find "significant meridional variability with enhanced #ParticulateOrganicCarbon production in the subantarctic & polar Antarctic sectors & enhanced #DissolvedOrganicCarbon production in the subtropical & sea-ice-dominated sectors." 3/8
"#ParticulateInorganicCarbon production peaks between 47°S and 57°S near the “great calcite belt.” Relative to an abiotic Southern Ocean (SO), organic C production enhances CO2 uptake by 2.80 ± 0.28 Pg C y−1, while PIC production reduces CO2 uptake by 0.27 ± 0.21 Pg C y−1." 4/8
"Without organic C production, the SO would be a CO2 source to the atm. The findings of this study emphasize the importance of #DOC & #PIC production, in addition to the well-recognized role of #POC production, in shaping the influence of C export on air–sea CO2 exchange." 5/8
IN SIMPLE WORDS ⬇️
🌊 "Researchers discovered that if the amount of #carbon produced by tiny organisms in Southern Ocean decreased by 30%, the Southern Ocean would release carbon dioxide instead of #absorbing it, which could worsen the #GreenhouseEffect on our planet." 6/8
Read the open-access paper entitled: "Biogenic carbon pool production maintains the Southern Ocean carbon sink" here ⬇️ pnas.org/doi/10.1073/pn…
🚨Monthly Solar Geoengineering Updates (April'2026)🚨
From EU calls for an #SRM deployment moratorium & WHO-linked health-centered governance report, to Stardust publishing its own SRM rules, key SRM headlines you need to know from past month:
🔗
The private SRM company publishes voluntary rules and safety guidelines, but experts raise concerns over transparency, unknown aerosols, and private control of planetary-scale interventions.
1/12
2️⃣ WHO-linked report calls for health-centered SRM governance:
A pre-print urges SRM governance centred on human health, equity, and Global South inclusion, stressing SRM must never replace emissions cuts (“non-substitution” principle).
🚨Is direct air capture (#DAC) really worth the investment?
A new Nature Climate Change study shows that investing in wind & solar delivers 2-3× greater combined climate + health benefits than direct air capture across most U.S. regions, under the same budget.
Details🧵1/11
2/ DAC is often promoted as essential for net-zero, removing CO₂ directly from the atm. But most studies assess it in isolation, asking: “Does it work?”
This study asks a policy-relevant question:
“What are we giving up by funding DAC instead of alternatives?”
3/ Researchers modelled cost-equivalent investments across 22 U.S. regions (2020–2050), comparing:
Direct Air Capture vs Utility-scale wind & solar
Critically, they evaluated CO₂ reductions + air pollution + health impacts.
🚨What happens to tropical rainforests as CO₂ rises?
New research shows higher CO₂ boosts tree growth & C uptake by pushing roots to aggressively mine scarce phosphorus.
This strengthens the C sink now, but depletes nutrients, ultimately limiting long-term C storage.🧵1/11
2/ Scientists tested this in the Amazon by exposing forest patches to higher CO₂ (future-like conditions) and tracking how trees, roots, and soils responded over time.
3/ Step 1: More CO₂ → faster photosynthesis
Trees produce more sugars, grow faster, and pull more CO₂ out of the air.
🚨Green roofs + enhanced rock weathering (#ERW) could turn cities into carbon sinks.
A new assessment finds Europe’s rooftops could remove tens of millions of tonnes of CO₂ by 2060, with global potential reaching hundreds of MtCO₂/yr under ideal conditions.
Details🧵1/12
2/ The work is a conceptual, literature-based assessment combined with geochemical scaling.
It estimates CO₂ removal using theoretical maximum reactivity (100% mineral conversion) and extrapolates across urban roof availability in Europe and globally.
3/ Roof availability is a key input:
The study uses estimates that roofs cover ~30–32% of urban land area, and up to ~50% of impervious surfaces in dense cities, highlighting a large, currently underused surface for carbon removal deployment.
🚨A new study details that the climate value of algae & cyanobacteria lies not in CO₂ uptake alone, but in their capacity to generate long-lived, chemically recalcitrant C compounds, such as algaenan & carbonates that may contribute to durable sequestration pathways.
🧵1/11
2/ The study adopts a conceptual synthesis framework, integrating biochemical & geochemical evidence to examine carbon fate post-photosynthetic fixation, moving beyond uptake rates to study the thermodynamic and structural persistence of biogenic carbon.
3/ It constructs a functional distinction between:
1) Labile carbon fractions, which are rapidly cycled through microbial respiration
2) Recalcitrant fractions, which resist degradation & contribute to long-term carbon storage across terrestrial & marine systems.