Norway bets on CO2 capture, storage despite risks

* Norwegian field safely reinjects CO2 since 1996

* StatoilHydro upbeat on CO2 storage in North Sea

* Environmental groups concerned CO2 may leak out

By Wojciech Moskwa and Karina Lavik

SLEIPNER PLATFORM, North Sea, May 28 (Reuters) - Norway sees carbon capture and storage (CCS) as a leading weapon to combat climate change and says the Sleipner field where it has buried carbon for 13 years demonstrates the technology is safe.

Green groups are sceptical about storing millions of tonnes of carbon dioxide underground without risking leaks, even though the United Nations believes a fourth of the cuts in emissions needed to keep climate change under control can come from CCS.

"There are quite big areas in the North Sea that are likely to be suitable for safe CO2 storage," said Olav Kaarstad, senior adviser on CCS for Norway's oil and gas producer StatoilHydro.

"We are learning as we go along but we are very optimistic," he said during a visit to the Sleipner T platform, which houses a treatment plant that takes carbon dioxide (CO2) out of the natural gas stream.