Diversifying Carbon Removal Strategies: The Optimal Solution to Save Our Planet

Last year, the Earth’s temperature surpassed 1.5°C above pre-industrial levels, a threshold beyond which wildfires, droughts, floods, and other climate change impacts are expected to worsen in frequency, severity, and devastation.

To limit global warming to this level and avoid such disasters, the nearly 200 countries that have signed the Paris Agreement on climate change must significantly reduce greenhouse gas emissions and take actions to remove carbon dioxide from the atmosphere, permanently storing it in the ground or beneath the surface.

So far, previous analyses of the potential for mitigating climate change impacts and the costs and benefits of various carbon removal options have focused on three main strategies:

First: Bioenergy with carbon capture and storage (BECCS), where plant materials that absorb CO2 are converted into fuel or burned to generate energy, with some of the carbon content captured and stored safely.

Second: Reforestation, where trees are planted on a large scale to absorb CO2.

Third: Direct air capture, a technology that separates CO2 from ambient air and stores it in geological reservoirs or uses it in the production of durable products.

In a new study conducted by researchers from the Massachusetts Institute of Technology (MIT), these options have been expanded to include:

Fourth: Biochar, the production of a solid black material resulting from heating plant biomass, such as wood, crop residues, or other plant waste, in the absence or limited presence of oxygen, a process known as pyrolysis. This biochar can be used in various applications, including carbon storage and reducing greenhouse gas emissions.

Fifth: Enhanced weathering, where mineral-rich rocks like basalt are crushed into fine particles and spread over agricultural or open lands. This increases the surface area for interaction and accelerates the process of CO2 absorption from the atmosphere.

These five strategies were evaluated in the study in terms of their potential to achieve the 1.5°C target, considering their impacts on land use, energy, and policy costs.

The study was published in the journal Environmental Science Letters, and the researchers used a comprehensive model to analyze multi-sectoral and regional economic policies. The study highlighted three key findings:

First: Diversifying the carbon removal portfolio is the most cost-effective strategy with the least impact on resources to achieve global net-zero emissions, which is essential for meeting the 1.5°C target. This approach reduces land and energy consumption while mitigating negative effects such as worsening food insecurity and energy supply shortages.

Second: There is no one-size-fits-all carbon removal portfolio at the global level, and the ideal portfolio depends on local conditions. For instance, reforestation offers significant benefits for countries like Brazil and regions in Africa, as it contributes to carbon sequestration and forest protection.

Third: Delaying implementation can be costly, as it leads to higher global carbon prices, hindering the efforts required to meet climate goals. The study recommends immediately implementing incentive policies to accelerate these efforts.