This is an idea to pump liquid CO2 into very deep waters, to act as a sink to the increasing percentage atmospheric carbon dioxide present. Current global estimates suggest that 25 billion tonnes of CO2 is released in the atmosphere each year (Davies et al. 2007). It is a relatively new and therefore expensive idea but, it would have severe albeit localised consequences on deep sea species (Barry et al. 2004). Benthic infauna and epifauna suffer respiratory stress and direct mortality from acidosis. Mobile species have the option to move away from the source and therefore lessen the effects, but they can still exhibit temporary symptoms such as loss of consciousness (Davies et al. 2007). If they are exposed for too long however they can die, the results do vary which species.
The pros and cons of this method need to be weighed and looked at very closely as it potentially could be very harmful for deep-sea species.