Chennai, March 9 (IANS) Tamil Nadu is taking steps to introduce a structured system to evaluate the environmental and climate impact of urban tree-planting initiatives.

A newly prepared roadmap proposes a scientific approach to quantify how expanding green cover in cities contributes to climate mitigation and strengthens urban ecological resilience.

The framework aims to provide a reliable method to track the multiple environmental benefits created by urban forestry programmes. These benefits extend beyond beautification and biodiversity conservation and include carbon capture, reduction in city temperatures, improved groundwater recharge, better flood management and overall ecological stability in rapidly urbanising regions.

The roadmap has been developed as part of the Indo-German Support Project for Climate Action in India and seeks to integrate climate-focused assessments into urban forestry initiatives in Tamil Nadu.

Experts involved in the project have emphasised the importance of developing measurable indicators so that the environmental gains of tree-planting programmes can be incorporated into climate planning and sustainability strategies.

Urban forestry programmes in Tamil Nadu have traditionally been designed to enhance green cover, restore ecological balance and improve biodiversity in cities. However, the wider climate benefits produced by these initiatives have not been systematically measured so far.

The absence of reliable data has limited the integration of urban forestry outcomes into policy planning, climate reporting and investment decisions.

Tamil Nadu has undertaken extensive tree-planting activities in recent years through the Green Tamil Nadu Mission. Between 2022-23 and 2025-26, more than 14.16 crore seedlings were planted across the state, covering a potential area of about 1.28 lakh hectares.

Preliminary assessments indicate that these plantations are capable of sequestering between two and three lakh tonnes of carbon dioxide annually.

While detailed data on urban plantations is still being compiled, conservative estimates suggest that around 25 lakh seedlings have already been planted in urban areas across the state. Plans are underway to plant an additional seven lakh seedlings in cities during the current year.

Despite the scale of the initiative, urban forestry programmes continue to face challenges such as limited land availability in cities and the need for sustained maintenance of plantations. The proposed methodology aims to quantify both climate mitigation and climate adaptation benefits of urban forests.

Carbon dioxide removal will be estimated through biomass accumulation in trees using field measurements such as trunk diameter or standard carbon sequestration factors.

In addition to carbon capture, the framework identifies four key adaptation indicators: reduction in urban heat island effects, improved groundwater recharge, better management of stormwater and flooding, and enhancement of biodiversity in urban ecosystems.

Trees play a crucial role in lowering temperatures through shading and evapotranspiration, while vegetation also improves soil infiltration and reduces surface runoff during heavy rainfall.

Several institutional and technical challenges have been identified in implementing the monitoring system. These include the absence of baseline environmental data, limited technical training for field staff and insufficient use of modern monitoring tools such as remote sensing and environmental sensors.

The roadmap recommends a phased rollout of the framework through pilot studies, policy guidance and capacity-building programmes. Integrating climate benefit assessment into existing urban forestry schemes is expected to strengthen environmental planning and enable authorities to track the long-term climate value of tree-planting initiatives.

–IANS

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