A sinking carbon feeling? Try isotope hydrology

IAEA water symposium examines topics related to climate change, other issues

Not many people see isotope hydrologists on the front line of the fight against climate change. But they are -- studying how to trap greenhouse carbon gas and bury it deep below ground in salty aquifers. The work is one topic being reviewed at the IAEA, when world experts in isotope hydrology meet 21-25 May in Vienna at an international symposium.

Over 280 participants will attend the International Symposium on Advances in Isotope Hydrology and Its Role in Sustainable Water Resources Development. Studies on carbon trapping and other topics from over 60 countries will be presented.

Carbon trapping -- or sequestration in technical terms -- is an emerging research area to combat global warming. It refers to natural or artificial processes that remove carbon from the atmosphere, to reduce or slow rising emissions through interaction with natural "sinks", mainly oceans, deep parts of the Earth's crust, or plants. In some processes, the carbon dioxide is injected into an underground water source where it dissolves and remains in long-term storage. That's where isotope hydrologists come in.

"Once the carbon dioxide is trapped in the water you want to make sure it stays put," says Brent Newman, a scientist in the IAEA's Isotope Hydrology section. "That's where isotope hydrology comes in. You use isotopes like carbon and oxygen to monitor if the carbon dioxide is leaking or flowing from the aquifer, and to assure the integrity of the aquifer is maintained. For carbon sequestration you need a brine aquifer where the water is thousands of years old. Isotope hydrology can tell you the age of the water. If it's very old, then it's unlikely the water is flowing out of the aquifer rapidly enough to be a problem. In addition, many brine aquifers have the capacity to absorb lots of carbon dioxide."