The United Nations has released a new report on the conditions of the oceans, calling for action to address what it says are unprecedented and enduring changes in the ocean and cryosphere.
The report highlighted the benefits of ambitious and effective adaptation for sustainable development, and conversely, the escalating costs and risks of delayed action.
According to the UN, global warming, due to past and current greenhouse gas emissions, has led to a warmer, more acidic and less productive ocean, while melting glaciers and ice sheets are affecting in-land water supply, agriculture and hydro electric power generation, and are also causing the sea level to rise.
“The open sea, the Arctic, the Antarctic and the high mountains may seem far away to many people,” said Hoesung Lee, chair of the Intergovernmental Panel of Climate Change. “But we depend on them and are influenced by them directly and indirectly — for weather and climate, food and water, for energy, trade, transport recreation and tourism, for health and wellbeing, for culture and identity.
“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,” he added.
With rising sea levels, many areas will be exposed to escalating flood risks, the report stated. And some island nations may become uninhabitable. Increases in tropical storm winds and rainfall are expected to exacerbate extreme sea level events and coastal hazards.
If greenhouse gas emissions remain high, the intensity of storms will also increase, according to the UN.
Ocean warming is also affecting the oxygen content and nutrients for marine life, and absorbing between 20 and 30 percent of human-induced carbon dioxide emissions since 1980, the ocean is becoming increasingly acidic, thus affecting marine life in coast areas, the open ocean and on the sea floor.
The report concluded that only by strongly reducing greenhouse gas emissions, protecting and restoring ecosystems, and carefully managing the use of natural resources will it be possible to preserve the ocean and cryosphere as a source of opportunities that support adaptation to future changes, limit the risks to livelihoods, and offer multiple additional societal benefits.
More than 100 authors from 36 countries were said to have assessed the latest scientific literature related to the ocean and cryosphere for the report, referencing some 7,000 scientific publications.