New research finds that ancient carbon in rocks releases as much carbon dioxide as the world's volcanoes https://perma.cc/S4WT-RGB5 A new study led by the University of Oxford has overturned the view that natural rock weathering acts as a CO2 sink, indicating instead that this can also act as a large CO2 source, rivalling that of volcanoes. The results, published today in the journal Nature, have important implications for modelling climate change scenarios. Professor Robert Hilton (Department of Earth Sciences, University of Oxford), who leads the ROC-CO2 research project that funded the study, said: “This is about 100 times less than present day human CO2 emissions by burning fossil fuels, but it is similar to how much CO2 is released by volcanoes around the world, meaning it is a key player in Earth’s natural carbon cycle”. A new study finds volcanic activity played a direct role in triggering extreme climate change at the end of the Triassic period 201 million year ago, wiping out almost half of all existing species. The amount of carbon dioxide released into the atmosphere from these volcanic eruptions is comparable to the amount of CO2 expected to be produced by all human activity in the 21st century https://perma.cc/VR49-5KBU Effect of volcanic eruptions significantly underestimated in climate projections https://perma.cc/FAS7-P7D7 While this effect is far from enough to offset the effects of global temperature rise caused by human activity, the researchers, led by the University of Cambridge, say that small-magnitude eruptions are responsible for as much as half of all the sulphur gases emitted into the upper atmosphere by volcanoes. The results, reported in the journal Geophysical Research Letters, suggest that improving the representation of volcanic eruptions of all magnitudes will in turn make climate projections more robust. However, these large eruptions only happen a handful of times per century – most small-magnitude eruptions happen every year or two. ... not compare with human CO2 ..