Stalactites and stalagmites in Siberia have shown evidence of thawing, threatening a release of giga-tonnes of stored carbon.
Research conducted in caves in Siberia has suggested that a global temperature rise of 1.5 degrees could cause regions of permafrost to begin to thaw. Permafrost naturally stores carbon, and if thawed could potentially release 1000 giga-tonnes of greenhouse gases, greatly increasing the rate of global warming.
This release of gases would cause extensive damage to natural ecosystems and human environments.
Read more at University of Oxford