The solution to climate change might be found right beneath our feet. In the soil! Yes, the soil! The loose material covering the Earth’s surface! The ‘earth’ on which plants establish and flourish! That soil! It can help our planet mitigate the effects of climate change. Soil is already recognised as one of the most prominent carbon reservoirs (in terms of storage) and carbon sinks (in terms of its ability to sequester carbon from the atmosphere). In fact, the global stock of organic carbon in soil is more than three times the amount found in the atmosphere, and more can be mopped up by the soil from the air. Carbon sequestration in soil is a promising strategy for reducing greenhouse gases, which are primarily released through the burning of fossil fuels. This method may be one of the more effective ways to return atmospheric carbon back to the ground.So, how do we push our soil to function better as a carbon pool and sink? Look towards plants and their ability to sequester soil carbon. Plants photosynthesise and turn gaseous carbon to solid and store them across their stems, trunks, leaves and roots. When plant parts or plants themselves die and get buried in the soil, they get broken down and form a significant portion of soil carbon. This carbon is known as Particulate Organic Matter (POM). Although a sizeable entity for carbon storage in soil, POM lasts in soil for less than a decade. It gets decomposed by microbial activity and subsequently released into the air through soil respiration as carbon dioxide. But there are other sources of soil carbon from plants. The root exudes organic material into the soil. These exudates get attached with minerals in the soil and tend to be far less vulnerable to soil respiration. They stay in the soil for decades or even centuries. Scientists refer to this soil carbon as Mineral-associated Organic Matter. This persistent soil carbon is a great candidate for soil carbon sequestration, as it easily outlives POM. To mitigate the impact of climate change, it is crucial to focus on MAOM and ensure that mitigation efforts enhance more persistent carbon in the soil. Different ecosystems vary in their ability to transfer carbon produced through photosynthesis into the soil. Grasslands can allocate over 60% of their productivity to their below-ground components, while forests transfer about 20%, and croplands transfer even less, around 10%. The higher the carbon allocation to roots, the greater the contribution to soil carbon sequestration, particularly in the form of MAOM, effectively illustrating that grasslands are very effective at storing significant amounts of long-lived carbon in their soil. Given that grassy biomes cover approximately 10% of India’s land surface, they present a substantial opportunity for meeting our international commitments on carbon sequestration. However, natural grasslands have historically been labelled as ‘wastelands‘ and are often targeted for tree-planting initiatives.Tree-planting initiatives have gained significant global attention, with many investments aimed at planting saplings in open habitats such as grasslands, scrublands, savannahs, and cleared areas. The visibility and cultural importance of trees have fuelled this movement. However, researchers have raised concerns about whether grasslands can support these afforestation efforts. Introducing trees into these ecosystems may create new habitats, potentially displacing native biodiversity that has thrived in these open environments for millions of years. Moreover, the ecosystem services provided by grasslands – such as water recharge, soil erosion control, and food production – could be disrupted. For example, groundwater recharge is more effectively performed by shallow-rooted grasses and shrubs than by deep-rooted trees. Soil erosion control may be compromised by planting trees in grasslands, where the effects of erosion can also involve the loss of soil carbon. Additionally, trees can shade the grasses that livestock rely on for sustenance, leading to a shortage of fodder for herders. Overall, planting trees in existing grasslands can have more harmful effects than initially anticipated.Trees may also hinder the long-term storage of carbon in the soil. Planting trees in arid and semi-arid grasslands for carbon sequestration is often ineffective at best, and counterproductive at worst. Most saplings fail to grow into mature trees, leading to significant financial losses for the government. Native grass species can endure extreme heatwaves, droughts, diseases, and wildfires common in such grasslands, while trees typically do not survive. Rather than serving as the carbon sinks they were expected to be, these trees eventually die and decompose, releasing carbon dioxide back into the atmosphere.A recent study published in the journal Weather says that the planet’s ‘appetite’ for soaking up carbon (by plants and soils of the land surface) has been declining steadily, thereby increasing the likelihood of climate collapse. Our last-minute scrambling for solutions — read as unscientific drives for tree planting in grasslands — can further undermine the efforts already made. Restoration efforts cannot focus solely on afforestation, particularly in landscapes that were once grasslands. It is crucial to train stakeholders and revise planning policies regarding grassland restoration. India is fortunate to have extensive areas of open natural ecosystems that play a vital role in combating global warming. The soil beneath the grass blades is already functioning as a natural solution to climate change.Dr Jobin Varughese is a postdoctoral researcher at the National Centre for Biological Sciences, Bangalore, working with the Centre for Pastoralism, Delhi.This is the fifth article in a series exploring the challenges faced by Indian pastoralists. Read the first, second, third and fourth.