Two USC authors contributed to the latest United Nations' Intergovernmental Panel on Climate Change report, Professor David Schoeman and Professor Patrick Nunn.

Below is a statement from Professor Schoeman, Professor of Global-Change Ecology in the School of Science, Technology and Engineering: 

"In the newly-released IPCC WGII report, scientists document thousands of impacts to ocean and coastal ecosystems caused by global warming, sea-level rise and ocean acidification.

"These are not impacts that await us in some dystopian future, but impacts we have already seen. Coastal ecosystems have borne the brunt of climate change so far, because this is where people most directly interact with marine biodiversity, and where human impacts other than climate change make climate impacts worse.

"But extensive new scientific evidence in the IPCC report shows that if we reach 1.5°C warming, climate impacts will escalate rapidly, and that some of these impacts will become irreversible for generations, if not centuries.

"This is especially pertinent because the IPCC late last year concluded that we stand a very good chance of reaching 1.5°C within the next 20 years, or earlier if we don’t start treating climate change as an urgent priority.

"Ecosystems like coral reefs, mangroves, salt marshes and seagrass meadows are at particular risk, as are the services that these ecosystems deliver to society.

"Given the large proportion of the world’s population that lives along coastlines, this is a serious concern. And more so for those who rely most directly on ecosystems for livelihoods and sustenance.

"As long as we remain below 1.5°C of warming, there are things we can do to help people and nature deal with the changing climate. This is called adaptation. For the coast and sea, adaptation centres around carefully-planned, effective and socially fair management of at least 30 per cent of the global ocean. And this is important because a healthy planet is essential for resilient societies. Although projected impacts at 1.5°C of warming are worrying, at higher levels of warming, potential impacts are worse. And the greater the warming and the longer it lasts, the less chance there is of reversing the resultant impacts in the future.

"Technology might be able to curb or even reverse greenhouse gas emissions, and control future global temperatures, but it is unlikely to be able to undo the damage that climate change has wrought.

"Given that we so far have not done enough to counter climate change, we have to accept that the 1.1°C of warming we have caused will result in some impacts we can’t avoid.

"But there is still an opportunity to avoid the worst. Although, the window of opportunity is closing fast, the quicker we are to take serious action, the greater the benefits will be for the people of the world.”

The full report is available here.

Professor Schoeman is a Lead Author on the IPCC Report (Chapter 3 on Ocean and coastal ecosystems and their services)