IPCC report reveals impacts on low-lying cities and communities

The Intergovernmental Panel on Climate Change’s (IPCC) latest Special Report on the Ocean and Cryosphere in a Changing Climate states sea level is rising at an increasing rate, alongside ocean warming and acidification, which will increase risks for low-lying coastal communities and biodiversity.

The report reveals the benefits of ambitious and effective adaptation for sustainable development and, conversely, the escalating costs and risks of delayed action.

Extreme ocean levels which historically would occur on average once in a century – what engineers call a one percent inundation level – are projected to occur annually by 2050 at most coastal locations around the world, depending on by how much further the planet warms, the IPCC said.

“In the absence of more ambitious adaptation efforts compared to today, and under current trends of increasing exposure and vulnerability of coastal communities, risks, such as erosion and land loss, flooding, salinization, and cascading impacts due to mean sea level rise and extreme events are projected to significantly increase throughout this century under all greenhouse gas emissions scenarios,” the report said.

“Under the same assumptions, annual coastal flood damages are projected to increase by 2–3 orders of magnitude by 2100 compared to today (high confidence)”.

One order of magnitude is 10 times the damages and three orders of magnitude is 1,000 times, which means this assessment has strong implications for Australia’s almost 60,000 km of coastline and the local councils that manage it. About 80 percent of the Australian population lives within 20 km of the coast.

Without major investments in adaptation, they would be exposed to escalating flood risks, the report shows.

Increases in tropical cyclone winds and rainfall are exacerbating extreme sea level events and coastal hazards. Hazards will be further be intensified by an increase in the average intensity, magnitude of storm surge and precipitation rates of tropical cyclones, especially if greenhouse gas emissions remain high.

The report finds that strongly reducing greenhouse gas emissions, protecting and restoring ecosystems, and carefully managing the use of natural resources would make it possible to preserve the ocean and cryosphere as a source of opportunities that support adaptation to future changes, limit risks to livelihoods and offer multiple additional societal benefits.

“We will only be able to keep global warming to well below 2°C above pre-industrial levels if we effect unprecedented transitions in all aspects of society, including energy, land and ecosystems, urban and infrastructure as well as industry. The ambitious climate policies and emissions reductions required to deliver the Paris Agreement will also protect the ocean and cryosphere – and ultimately sustain all life on Earth,” said Debra Roberts, Co-Chair of IPCC Working Group II.

SROCC provides the best available scientific knowledge to empower governments and communities to take action, embedding that scientific knowledge on unavoidable change and plausible futures into their own context, to limit the scale of risks and climate impacts. The report gives evidence of the benefits of combining scientific with local and indigenous knowledge to develop suitable options to manage climate change risks and enhance resilience.

This is the first IPCC report that highlights the importance of education to enhance climate change, ocean and cryosphere literacy. - 5 - “The more decisively and the earlier we act, the more able we will be to address unavoidable changes, manage risks, improve our lives and achieve sustainability for ecosystems and people around the world – today and in the future,” Roberts said.

The report is available to download here.

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