A major new report has warned of the grave danger faced by our planet’s oceans as the climate crisis deepens. The main takeaway is simple: the climate crisis is an oceans crisis. 

The new report by the Intergovernmental Panel on Climate Change (IPCC), a body of the United Nations, looks to provide the most comprehensive assessment to date of the current and future impacts of climate change on our oceans. Their findings represent the work of 104 scientists from 36 countries and reference nearly 7,000 published papers on the latest climate science. You can read a summary of the report here.

Oceans and the cryosphere (the frozen parts of the world) have been “taking the heat” from climate change, absorbing over 90 percent of the excess heat in the climate system and up to 30 percent of human-induced carbon dioxide emissions. Now, the effects of this are becoming starkly clear. 

One especially worrying example was that extreme flooding could start to occur once a year or more within a century. Other natural hazards, such as avalanches and landslides, will also rise as glaciers and permafrosts decline.

Human activity is also dramatically messing with the water chemistry of our oceans. Pumping carbon emissions into the atmosphere results in the oceans uptaking more carbon dioxide, which makes the water more acidic. It isn’t just coral reefs that will suffer from ocean acidification; all marine life will be impacted by this, either directly or as a result of impacts to habitat or food. On top of that, marine life will also struggle to cope with the rising temperatures of the sea. Communities that depend highly on seafood may face risks to nutritional health and food security.

The melting of the world’s cryospheres was another big issue in the report, which highlights that if global warming is stabilized at 1.5°C above pre-industrial levels, the Arctic ocean would only be ice-free in September once in every hundred years. However, if global warming reaches 2°C, this will occur every three years on average.

As a result of the ice caps and glaciers thawing, especially in the Arctic, the updated projections of sea-level rise by 2100 are now even higher than those made in 2014.

“Sea level is currently rising more than twice as fast and will further accelerate reaching up to 1.10 meters in 2100 if emissions are not sharply reduced,” said Valérie Masson-Delmotte, co-chair of the IPCC Working Group I in a statement.

While many of these negative effects will occur regardless of any efforts to curb climate change and reduce greenhouse gas emissions, not all hope is lost. The report concludes by showing how sharp policy change could negate some of this damage before it’s too late. 

“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,” said Hoesung Lee, Chair of the IPCC. 

“Cutting greenhouse gas emissions will limit impacts on ocean ecosystems that provide us with food, support our health and shape our cultures,” added Hans-Otto Pörtner, Co-Chair of IPCC Working Group II. “Reducing other pressures such as pollution will further help marine life deal with changes in their environment, while enabling a more resilient ocean.”