A peer-reviewed study by 20 scientists has challenged the cumulative environmental impact assessment prepared by the Wildlife Institute of India for the proposed doubling of the Tinaighat-Kulem railway line in Karnataka and Goa. The study says the assessment overlooks biodiversity and ecological impacts across one of the region's most sensitive forest landscapes. The authors describe the matter as urgent given the scale of planned infrastructure. The review was published in the Journal of Threatened Taxa and was carried out by a multidisciplinary team of ecologists, social scientists, conservationists and independent researchers. The team assessed the 2025 environmental impact assessment and found methodological gaps, incomplete baseline data and absence of cumulative impact analysis. The authors call for independent scrutiny before environmental clearance is finalised. Nearly 26 km of the line passes through the Kali tiger reserve and Goa's Bhagwan Mahavir wildlife sanctuary and national park, raising conservation concerns. The doubling is part of a 342-km expansion intended to improve connectivity between Karnataka's mining hinterland and the port of Vasco in Goa. Reviewers warn that proximity to protected areas increases ecological risk if mitigation is inadequate. The paper notes that habitat fragmentation, disruption of wildlife corridors and disturbance to endemic flora and fauna are not adequately quantified in the EIA. It says cumulative effects from ancillary infrastructure, increased train frequency and construction activity require landscape-level assessment. The reviewers recommend scenario modelling and long-term monitoring frameworks to guide decisions. Local ecological networks and species reliant on contiguous forest tracts are described as vulnerable to altered movement patterns and habitat loss. The study emphasises integrating conservation planning with transport development to minimise irreversible losses. It warns that decisions will determine the persistence of key populations in the region. The authors urge authorities to commission independent audits and to revisit mitigation planning to incorporate robust scientific inputs and community safeguards. They recommend that any clearance be conditional on demonstrable measures to avoid cumulative damage and on binding monitoring commitments. The review frames the choice as a test of how development and conservation are balanced in biodiverse landscapes.