The latest Intergovernmental Panel on Climate Change (IPCC) Special Report highlights the urgency of prioritizing timely, ambitious and coordinated action to address unprecedented and enduring changes in the ocean and cryosphere.

The report is a key scientific input for world leaders gathering in forthcoming climate and environment negotiations, such as the UN Framework Convention on Climate Change Conference (COP25) in Chile in December.

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

The ocean and the cryosphere (the frozen parts of the planet) play a critical role for life on Earth. A total of 670 million people in high mountain regions and 680 million people in low-lying coastal zones depend directly on these systems. 

Global warming has already reached 1°C above the pre-industrial level, due to past and current greenhouse gas emissions. 

The reports findings include:

• glaciers, snow, ice and permafrost are declining and will continue to do so, thus increasing hazards for people, for example, adversely affecting agriculture and hydropower, recreational activities, tourism and cultural assets;
• sea level will continue to rise for centuries and could reach around 30 to 60 cm by 2100, even if greenhouse gas emissions are sharply reduced and global warming is limited to well below 2°C, but around 60 to 110 cm if greenhouse gas emissions continue to increase strongly;
• sea level rise will increase the frequency of extreme sea level events, which occur, for example, during high tides and intense storms, increasing risks for many low-lying coastal cities and small islands;
• ocean warming reduces the supply of oxygen and nutrients for marine life, which affects global fish populations;
• the ocean has taken up between 20 to 30 percent of human-induced carbon dioxide emissions since the 1980s, causing ocean acidification, and continued carbon uptake by the ocean by 2100 will exacerbate ocean acidification.

The report states 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.

To learn more, contact the IPCC Working Group II Technical Support Unit: tsu@ipcc-wg2.awi.de, or Maike Nicolai: maike.nicolai@ipcc-wg2.awi.de.