Basalt dust boosts tree carbon storage by 27% in UK field trial
A UK study in the largest field trial found that applying basalt dust to forests can increase tree carbon storage by 27%, offering a potential climate change mitigation technique.
The Full Story
A plain summary built from the channels that reported this story.
A major field trial in the UK has found that spreading basalt dust on forest soil can increase the amount of carbon stored by trees by 27 percent. The study, described as the largest of its kind in the world, was carried out over four years in Glandear Forest in mid-Wales. Researchers from Imperial College London worked with a team of nearly 300 volunteer citizen scientists to measure the effects of crushed basalt rock on newly planted broadleaf trees.
The basalt dust, a byproduct of quarrying, was spread on the ground before planting. The trial involved 72 different plots with various tree species, some treated with the dust and some left untreated. After four years, the treated trees showed 85 percent faster initial growth and, crucially, 27 percent more carbon sequestration. The scientists attribute this to enhanced rock weathering, a natural process that locks away carbon dioxide.
Key findings from the trial:
- 27 percent more carbon stored in trees grown with basalt dust compared to untreated trees.
- 85 percent faster growth in the early stages for saplings treated with the dust.
- The method is described as a "quick win" for climate mitigation, particularly on acidic soils.
- The trial is the largest field experiment of its kind globally, involving 75,000 site samples.
The lead scientist, Professor Charles Nickles, said the results are significant. "If you're going to plant broadleaf trees as part of a restoration project and you're on acidic soil and you put crushed basalt down, you're going to sequester nearly a third more carbon. Easy to do and a quick win."
The research comes at a time when the UK is falling short of its tree-planting targets, and many newly planted trees die. The basalt dust method could help improve survival rates and carbon capture. However, the study's authors caution that scaling up the technique globally depends on political will. The world currently needs to remove about nine billion tonnes of CO2 per year, but existing technologies only manage a few million tonnes.
The trial used an app designed by the Carbon Community charity to monitor every tree. Volunteers measured trunks and collected soil and water samples, which were analysed at Imperial College London. The team believes the method could be applied not only to forests but also to gardens and larger land restoration projects.
While the science is promising, the researchers stress that large-scale deployment requires government and industry support. The findings offer a practical, low-tech option for boosting the climate benefits of reforestation efforts.
On screen
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Key Claims
Claims reported during this story's coverage, mapped by channel. Ordered by how many channels carried each claim.
| Claim | Channel 4 |
|---|---|
| A field trial found that applying crushed basalt to forest soil increased carbon sequestration by 27 percent over four years. | |
| Global carbon removal needs are estimated at nine billion tons per year, while current technologies remove only a few million tons. | |
| The trial was described as the largest field trial of its kind in the world. |
Channel Perspectives
What each channel focused on, with key quotes.
Channel 4 News framed the story as a hopeful, practical climate solution, emphasising the scale of the trial and the volunteer effort. The tone was positive and urgent, linking the research to the broader climate crisis and the need for quick wins. The report included vivid on-the-ground footage from the quarry and forest, and highlighted the political challenge of scaling up.
- “Well, the headline is with the um crushed rock the alzrock weathering 27 more carbon sequestered after four years. I mean that that is a that is a big number”
- “Easy to do and uh and a quick win”
- “We think that we need to remove about nine billion tons of carbon dioxide from the atmosphere every year for the next couple of decades And with our current carbon dioxide removal technologies, we're struggling even to remove a couple million tons”
Broadcast Timeline
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