Grassland Diversity Loss Could Cut CO2 Uptake
Why in News?
- On 12 October 2026, Down To Earth reported a study in the Proceedings of the National Academy of Sciences that finds loss of plant diversity could cut global grassland CO2 uptake by about 15 per cent by 2050.
- The study was led by Stephen Wirth of the Potsdam Institute for Climate Impact Research, with Kiel University researchers. It simulated grasslands from 1850 to 2100 under low-emission and high-emission scenarios.
- Under 2°C of warming, low-diversity grasslands would take up about 11 billion tonnes less CO2 a year in 2050.
- The study identifies India among the regions where gross primary productivity could be up to 50 per cent lower under low diversity.
- 2026 is also the United Nations International Year of Rangelands and Pastoralists.
Key Terminologies
- Gross primary productivity
- The total amount of carbon that plants fix through photosynthesis. It measures how much CO2 a grassland draws from the air.
- Functional diversity
- The mix of plant strategies in a grassland. The study groups plants as competitors, stress-tolerant plants and ruderals, and tests what happens when this mix narrows.
- Rangelands
- Grasslands, savannas, shrublands, deserts, wetlands and mountain areas used for grazing. The Food and Agriculture Organization says they cover about half of Earth's land surface.
- Emission scenarios
- Climate model pathways. The study used SSP1-2.6, a low-emission path below 2°C, and SSP3-7.0, a high-emission path of around 4°C.
Key Issues
- Carbon Loss: The study finds grasslands could absorb about 15 per cent less CO2 through photosynthesis by mid-century if diversity is lost. In some of the most affected regions, uptake could fall by 50 per cent.
- India at Risk: The strongest reductions in gross primary productivity are around the equator, in Paraguay and India, where it is up to 50 per cent lower in the low-diversity scenario.
- Degraded Base: The Food and Agriculture Organization says rangelands hold about 30 per cent of global soil organic carbon, and roughly half of rangelands are degraded.
- Livelihoods: Pastoralists manage at least 25 per cent of the world's land and herd about 1 billion animals. The authors stress that diversity matters for grazing and for the people who depend on it.
- Model Uncertainty: The researchers say the exact size of the effects is uncertain because the model simplifies plant traits and interactions. Some parts of Africa and Spain could see higher productivity under low diversity.
Key Implications
Positive/Pros/Merits
- Clear Policy Signal: The study ties biodiversity to climate, which supports grassland protection as a climate measure and not only a conservation one.
- Adaptation Guidance: Friedhelm Taube of Kiel University called for agricultural policy that helps farmers adapt, particularly in the Global South.
- Global Attention: The International Year of Rangelands and Pastoralists in 2026 gives these ecosystems a platform for new commitments.
Negative/Cons/Demerits
- Policy Gaps: India published its first guide to grasslands only on 17 August 2026, which shows how recently these ecosystems entered policy attention.
- Model Limits: The study is a simulation. Its figures should be read as risks and not as forecasts for any single site.
- Competing Land Use: Rangelands face degradation and pressure from other land uses. FAO says half of them are already degraded.
Key Initiatives
- India's Guide to Grasslands and Open Natural Ecosystems: The Government of India launched it at the 17th Conference of the Parties to the UN Convention to Combat Desertification in Mongolia on 17 August 2026. It covers grasslands, savannas, deserts, scrublands, ravines and coastal ecosystems.
- Project Great Indian Bustard: The Ministry of Environment, Forest and Climate Change, the Rajasthan and Gujarat forest departments and the Wildlife Institute of India announced a first inter-State initiative on 30 March 2026. A chick hatched in Kutch.
- Food and Agriculture Organization: The United Nations declared 2026 the International Year of Rangelands and Pastoralists, with the #IYRP2026 campaign on pastoralists' contribution to food security and biodiversity.
- UNCCD: The 17th Conference of the Parties in Mongolia provided the platform for the Indian guide, with a video message by Environment Minister Bhupender Yadav.
The Government of India says healthy grasslands are indispensable for biodiversity, livelihoods and climate resilience, as Environment Minister Bhupender Yadav said when launching the grasslands guide on 17 August 2026. The Ministry of Environment, Forest and Climate Change is also running Project Great Indian Bustard with State forest departments. The guide is a reference document and not a law.
Director's Perspective
Way Forward
- Map India's grasslands and rangelands by diversity and degradation, so protection can focus on the places the study flags.
- Protect native plant mixes in grazing lands and avoid replacing them with single-species cover.
- Support herders with grazing rights and fodder planning, since the livelihoods of pastoralists depend on diverse pastures.
- Add grasslands to national climate reporting alongside forests, so their carbon role is counted.
The study makes a credible case that grassland diversity is a climate asset, but it should be read with its stated uncertainty. It links a 15 per cent global drop in uptake to diversity loss and flags India among the exposed regions. It is a model study, and India has only recently published its first grassland guide. In a Mains answer, credit the guide and Project Great Indian Bustard, then conclude that India must count and protect grasslands in climate and land policy.
GS Relevance
Frequently Asked Questions
What does the 2026 study on grasslands and carbon find?
The study in the Proceedings of the National Academy of Sciences finds that grasslands could absorb about 15 per cent less CO2 by 2050 if plant diversity is lost. Under 2°C of warming, low-diversity grasslands would take up about 11 billion tonnes less CO2 a year.
Why does the study matter for India?
The study identifies India among the regions where gross primary productivity could be up to 50 per cent lower under low diversity. The authors stress that diversity also matters for grazing and the livelihoods of people who depend on pastures.
What has India done for grasslands in 2026?
India launched its first guide to grasslands and open natural ecosystems at the UNCCD Conference of the Parties in Mongolia on 17 August 2026. On 30 March 2026, the Environment Ministry also announced a first inter-State initiative for the Great Indian Bustard with Rajasthan and Gujarat.
PYQ Practice — Statement Analysis
1 The United Nations has declared 2026 the International Year of Rangelands and Pastoralists.
The Food and Agriculture Organization hosts the campaign page.
2 Gross primary productivity is the amount of carbon that plants fix through photosynthesis.
It indicates how much CO2 a grassland takes up.
3 Project Great Indian Bustard was launched by the Ministry of Environment, Forest and Climate Change, with the first inter-State initiative announced in 2026.
The initiative involves the Rajasthan and Gujarat forest departments and the Wildlife Institute of India.