evidence: Massive volcanic carbon dioxide (CO2) emissions contributing to an extreme global ocean deoxygenation event over 120 million years ago has modern day implications for understanding a climate warming "tipping point," according to new research published in Nature, led by a scientist at Ocean Networks Canada, a University of Victoria initiative. [...] "Our work shows that massive volcanic carbon emissions led to a rapid increase in atmospheric CO2 concentrations and the crossing of a climate-warming threshold, or tipping point, that resulted in widespread ocean deoxygenation. Following this, Earth's climate system then remained in a warmed state for over two million years," says Bauer, who began the work while at Hong Kong University's Department of Earth Sciences and completed it at UVic.