Carolyn D. Ruppel 2011 As the evidence for warming climate became better established in the latter part of the 20th century (IPCC 2001), some scientists raised the alarm that large quantities of methane (CH₄) might be liberated by widespread destabilization of climate-sensitive gas hydrate deposits trapped in marine and permafrost-associated sediments (Bohannon 2008, Krey <i>et al.</i> 2009, Mascarelli 2009). Even if only a fraction of the liberated CH₄ were to reach the atmosphere, the potency of CH₄ as a greenhouse gas (GHG) and the persistence of its oxidative product (CO₂) heightened concerns that gas hydrate dissociation could represent a slow tipping point (Archer <i>et al.</i> 2009) for Earth's contemporary period of climate change. application/pdf en Nature Publishing Group Methane hydrates and contemporary climate change article