- A new report from the United Nations has highlighted the impact of climate change on our oceans, from rising sea levels to a warmer, more acidic seas.
- Rising sea levels are particularly threatening to coastal areas, causing more extreme tropical storms.
- Australian coastal regions could face the brunt of these extreme weather events, and one climate change expert suggests preparing coastal infrastructure for possible damage.
The ocean is becoming warmer and more acidic, spelling bad news for Australia's coastal regions.
A new report from the United Nations Intergovernmental Panel on Climate Change (IPCC) highlighted the effects of climate change on the ocean and cryosphere - the frozen parts of the planet.
The report mentions that global warming has reached 1°C above the pre-industrial level due to past and current greenhouse gas emissions. This has caused rising sea levels (hello, melting ice sheets in Greenland and Antarctica) as well as a warmer, more acidic, and less productive ocean, which can threaten low-lying coastal cities and small islands.
The IPCC noted that while the sea level has risen globally by about 15cm during the 20th century, it is currently rising more than twice as fast – 3.6mm a year – and accelerating.
Rising sea levels increase the frequency, intensity and magnitude of tropical cyclone winds and rains, the IPCC states. And if nothing is done to reduce greenhouse gasses, low lying coastal towns could be exposed to rising flood risks.
Worse still, the IPCC said some island nations are "likely to become uninhabitable" due to climate-related ocean and cryosphere change.
Pacific island nations such as Fiji, Tuvalu, Kiribati and Vanuatu could be completely submerged within a few decades if sea levels continue rising at their current rates.
Australian Conservation Foundation CEO Kelly O’Shanassy said in a statement, “Australians love days on the beach and getting out on the water – 21 million of us live within 50 kilometres of the coast.
“This is a stark warning from the world’s best scientific minds that climate change is harming our oceans, meaning more coral bleaching, more storms that lead to flooding and more bushfire-fuelling El Niños if our pollution keeps rising."
Australian National University Associate Professor Nerilie Abram, climate change scientist and coordinating lead author of the IPCC report, said globally by 2050 more than one billion people will live on coastal land which is less than 10 metres above sea level. And they will be exposed to extreme flooding and storms surges from more intense tropical cyclones.
"Their future looks dire if we do not act to limit further climate change," Abram said in a statement.
"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."
The report added that ocean warming and rising ocean acidity also impacts the distribution and abundance of marine life in coastal areas. Meaning your seafood could be impacted.
"Shifts in the distribution of fish populations have reduced the global catch potential," the IPCC said. "In the future, some regions, notably tropical oceans, will see further decreases, but there will be increases in others, such as the Arctic. Communities that depend highly on seafood may face risks to nutritional health food and security."
The best way to solve all this? Urgently reducing greenhouse gas emissions.
“If we reduce emissions sharply, consequences for people and their livelihoods will still be challenging, but potentially more manageable for those who are most vulnerable,” IPCC Chair Hoesung Lee said.
Abram added that reducing greenhouse gas emissions can give Australia extra time to prepare parts of its coastal infrastructure from extreme weather events.
"In Australia, adapting coastal communities to unavoidable sea level rise is likely a priority," she 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 defenses."
O’Shanassy said "Australia has so much to lose" if we continue polluting our atmosphere.
“We love the Great Barrier Reef, Ningaloo Reef and our other spectacular coral ecosystems. We love our beaches. We love fishing and water sports. We need to protect these with urgent climate action," she said.
And we need to do it now, before it's too late.