Boggle and Chandler died as a result of and eruption of Co2 due to and accumulation of organic mater decomposing in the bottom of the river - nothing to do with Co2 accumulation in the Ocean which by the way ends up resulting in more limestone deposits. You need to get your facts right.
It was one of those extremely rare events and if they hadn't been lying on the ground so close to the rivers edge it would never had happened. It took many years to work out what had occurred.
