Evidence of ancient wildfires preserved in coal reveals clues to Earth's climate

📌 Summary:

• Researchers found molecular evidence of massive wildfires that swept across ancient Gondwana forests nearly 250 million years ago (the Permian period), shaping Earth's climate, vegetation and coal-forming environments
• The study was conducted by researchers from the Birbal Sahni Institute of Palaeosciences (BSIP), an autonomous institute of the Department of Science and Technology (DST)
• They used a novel multi-proxy approach — combining palynofacies analysis (study of tiny organic matter in sedimentary rocks) with Raman spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy — on coal-bearing sediments of the Godavari Valley Coalfield, India
• Key result: distinguishing high-intensity (h-PAL-CH) and low-intensity (l-PAL-CH) palaeofire-derived microcharcoal particles, based on their morphology, state of preservation and optical characteristics
• The results were supported by molecular combustion signatures — Raman spectral features of structural ordering (polycyclic aromatic hydrocarbons) and diagnostic FTIR functional groups of thermal alteration
• The method bridges the gap between visual identification of palaeofire residues and their geochemical characterization
• The study (published in Geological Journal, Wiley) can improve models of long-term climate change and help forecast ecosystem behaviour during extreme events like wildfires, which are becoming more relevant in a changing climate

🎯 UPSC Relevance: GS1 (Geography) — palaeoclimate reconstruction, climate change and palaeofire; GS3 — research and indigenous scientific capability.

📝 Prelims Facts:

• The study was conducted by the Birbal Sahni Institute of Palaeosciences (BSIP), an autonomous institute under the DST
• The wildfires date to the Permian period (~250 million years ago), in ancient Gondwana forests
• Study site: Godavari Valley Coalfield, India
• Techniques used: palynofacies analysis, Raman spectroscopy and FTIR spectroscopy

🔑 Key Term: Palaeofire — ancient fire activity in geological history, reconstructed from charcoal and other combustion residues preserved in sedimentary rocks, used to understand past climate and vegetation.