CANBERRA, Sept. 26 (Xinhua) -- Australia's coastal cities can expect extreme flooding at least once a year by 2050 with ocean's rise, according to a report.
An Intergovernmental Panel on Climate Change (IPCC) report released on Wednesday, which was co-authored by Nerilie Abram from Australian National University (ANU), found that sea levels could rise by 30-60 cm by the year 2100.
"Australia's coastal cities and communities can expect to experience what was previously a once-in-a-century extreme coastal flooding event at least once every year by the middle of this century - in many cases much more frequently," Abram said in a statement.
She said immediate action on climate change could buy an extra decade of time to prepare coastal infrastructure that would protect against the effects of floods or "even avoid them significantly."
"But even if we act now, some changes are already locked in and our ocean and frozen regions will continue to change for decades to centuries to come, so we need to also make plans to adapt," Abram said.
"There are a range of possible options, from building barriers to planned relocation, to protecting the coral reefs and mangroves that provide natural coastal defences."
More than 100 scientists in the world contributed to the report.
They found that sea levels rose 15 cm during the 20th century, but currently rising more than twice as fast -- 3.6 mm per year -- and accelerating.