"Utilization of biochar as a cementitious material aids in CO2 sequestration by impeding the release of C in the atm. So, a recent study reviewed the prospect of #biochar as a #cementitious material by evaluating its physical, mechanical & durability properties."🧵
This research suggested that "the physical properties of #biochar promote its use as an environmental control device."
A summary of the preparation and characterization of biochar is presented in a Fig. ⬇️ 2/7
According to the study, #pozzolan is a siliceous & aluminous material
that chemically reacts with Ca(OH)2 at room temp to form compounds having #cementitious attributes. So, some of the silica-rich biochars, like the ones derived from #RiceHusk have pozzolanic properties." 3/7
"The quantity & type of biochar used, the number of curing days & the curing technique all have an impact on the strength of biochar-infused concrete/mortar. However, investigations concluded that biochar used at lower conc. (<5 wt%) produce high-strength mortar+concrete." 4/7
This research recommended that "most of the prior work focuses on the thermal stability of #biochar. However, research on chemical & chloride attacks as well as the ageing & weathering study is scarce. Thus, future work should focus on the aforementioned gaps in knowledge."
5/7
Read the open-access study entitled: Biochar in cementitious material—A review on physical, chemical, mechanical, and durability properties" here ⬇️ aimspress.com/article/doi/10…
This episode dives into a radical proposal: using a buried nuclear explosion on the seafloor to break up basalt & speed up carbon removal via Enhanced Rock Weathering. The goal? Sequester 30 years of global CO2.
2/12
This episode unpacks a preprint by Hosea Olayiwola Patrick drawing lessons from COVID-19 for solar geoengineering.
📰 Here's your round-up of top #CarbonDioxideRemoval News / Developments from this week (09 June - 15 June 2025):
🔗:
🧵0/17
@InSoilClimate secured its largest funding to date through a €100 million agreement with Key Carbon, accelerating regenerative agriculture and carbon credit generation across Europe.
Canada Nickel partnered with NetCarb to scale mineral carbon sequestration at Crawford. NetCarb's tech could boost CO₂ uptake 10‑fold to 10–15 Mt/year, vs 1.5 Mt via Canada Nickel's proprietary IPT Carbonation.
🚨A new study [preprint] shows that injecting sulfur at 50km could make #SolarGeoengineering much safer.
It cools the planet more effectively, speeds ozone recovery & avoids stratospheric disruptions. This could be done using a fleet of clean, reusable H2 rockets.
DETAILS🧵1/10
2/ SAI involves spraying SO₂ into stratosphere, where it forms aerosols that reflect sunlight—cooling Earth. It mimics volcanic eruptions like Mt. Pinatubo (1991), which temporarily cooled the planet.
But current “SAI models” inject SO2 at a rate of 10 Tg/yr at ~25km altitude.
3/ But Injecting at 25 km creates problems
Aerosols accumulate in the tropical lower stratosphere, causing up to 6°C warming in that layer.
This disturbs jet streams, increases stratospheric water vapor, and delays the ozone layer’s recovery—by 25–55 years in Antarctica.
🚨A new study has revealed for the first time that ancient carbon, stored in landscapes for thousands of years or more, can find its way back to the atmosphere as CO₂ is released from the surfaces of rivers at a rate of 1.2 billion tonnes per year.
Details🧵1/8
2/ To understand the true source of river CO₂, researchers compiled a global dataset of 1,195 radiocarbon measurements of dissolved inorganic carbon (DIC), CO₂ & CH₄ from rivers & streams.
This let them determine whether the emitted carbon was modern—or much older.
3/ Using radiocarbon signatures (¹⁴C), they found that 59% of river CO₂ emissions come from "old" C—millennia-old soil carbon & even petrogenic carbon (rock-derived, >55,000 years old)
Only ~41% came from recent biological sources like plants & microbes (decadal carbon).