. 21/10/2024 4:22 PM
Why in News?
A Darjeeling-based company, Alt Carbon, is turning mining dust into a climate-friendly solution by utilising a geo-chemical process known as enhanced rock weathering (ERW) to tackle atmospheric carbon dioxide (CO2). The company has secured $500,000 in investments from carbon-credit companies to support this innovative approach.
Rocks naturally decompose over thousands of years due to rain and heat.
This breakdown leads to the formation of bicarbonates as atmospheric CO2 reacts with minerals like calcium and magnesium.
These bicarbonates eventually make their way to the oceans through aquifers, where they have the capacity to store or sequester carbon for thousands of years.
Carbon sequestration is the process of capturing and storing atmospheric CO2, helping reduce the amount of CO2 in the atmosphere with the goal of mitigating climate change.
Given the urgent need to reduce atmospheric CO2 levels – supported by the Intergovernmental Panel on Climate Change (IPCC) – there is a growing focus on accelerating natural carbon removal processes.
Enhanced rock weathering (ERW) offers a promising nature-based solution for this challenge.
ERW is a process that accelerates the natural weathering of rocks to remove CO2 from the atmosphere and help address climate change:
The method involves spreading finely ground silicate rocks (such as basalt) on land.
This increases the surface area of the rock, speeding up the chemical reactions between the rocks, water, and air.
Carbon sequestration: ERW can help remove CO2 from the atmosphere.
Improved soil: ERW can enhance soil pH, nutrient uptake, and fertility.
Reduced ocean acidification: ERW can help mitigate the effects of ocean acidification.
Energy consumption: Mining, grinding, and transporting rock consume significant energy, primarily from fossil fuels, which could offset the CO2 benefits.
Land requirements: Effective enhanced weathering requires large areas of land, necessitating participation from numerous farms or coastal regions for meaningful carbon removal.
High costs: Enhanced weathering is more expensive compared to other direct methods of dealing with carbon emissions.
Basaltic rock, especially abundant in regions like Maharashtra and Gujarat due to the volcanic Deccan Traps, is rich in minerals essential for carbon sequestration.
By crushing the rock into a fine powder, Alt Carbon increases its effective surface area, enhancing the formation of bicarbonates significantly – by ten to a hundred times.
Alt Carbon collects crushed basalt from Rajmahal mines and transports it to Darjeeling, where it is applied to tea estates.
This process not only enriches the soil but also accelerates carbon sequestration.
The company has utilised around 500 tonnes of basalt dust, aiming to sequester 50,000 tonnes of CO2 in the coming years, making mining dust climate-friendly.
Alt Carbon's innovative approach has attracted attention from major companies.
They have entered a partnership with Frontier – a consortium including McKinsey and Alphabet – to secure carbon credits worth $500,000.
They also collaborated with NextGen to buy additional carbon credits at $200 per tonne.
While the principles of ERW are well understood, discrepancies in measuring sequestered carbon raise concerns and emphasise the need for precise measurement protocols.
Alt Carbon’s pioneering work in using crushed basalt for ERW showcases a novel method for carbon sequestration. Moving forward, the company aims to make significant strides in combating climate change while simultaneously improving agricultural practices.
