The United Nations Environment Programme (UNEP) has released a report, ‘The Global Environment Outlook, Seventh Edition: A Future We Choose (GEO-7) that it said represents the most comprehensive scientific assessment to date focusing on the current state and future trends of the global environment.
The National Oceanography Centre (NOC) senior researcher Dr. Catia Domingues contributed to the report’s chapter on ‘Oceans and Coasts’. She reinforced the concern that the ocean, which is Earth’s greatest climate regulator, is reaching critical limits, which will have long-lasting impact on the planet we know today.
“The ocean is undergoing unprecedented physical and biogeochemical transformation,” Domingues said. “The GEO-7 report emphasises the urgent need to take action. Rapid emission reduction is essential to decrease changes and to limit the resulting impact. This will help to safeguard marine life, stabilise the climate and protect human livelihoods.”
Key findings on ‘Ocean and Coasts’ include:
- The ocean warming is accelerating, causing marine heatwaves and long-term change. The rate of surface warming has quadrupled over the past four decades. Marine heatwaves are becoming more frequent. All ocean basins are warming, with the Arctic and semi-enclosed seas (such as the North Sea and the Mediterranean) warming nearly twice as fast as the global average
- The Atlantic Meridional Overturning Circulation (AMOC) appears to be weakening, which could have far-reaching consequences. The AMOC was stable for around 8,000 years but has weakened since the late 19th century.
- Ocean deoxygenation is a growing and long-lasting threat which suffocates marine life and undermines ecosystem resilience. Global oxygen concentration is declining, driven by ocean warming. More than 700 coastal areas now suffer from low-oxygen conditions. Once depleted, oxygen recovery is slow
- Ocean acidification is accelerating fast, particularly in the Arctic and coastal regions. The ocean has absorbed around a quarter of human carbon dioxide emissions, making it more acidic with acidity increasing by about 30% since the 1750s – this marks the fastest rise in 26,000 years.
- Sea-level rise is increasing, threatening coasts and coastal communities around the world. The 20th century sea level rise is unprecedented in at least 3,000 years, with rapid acceleration since the 1960s-70s. Sea-level rise will persist for millennia, making it effectively irreversible under current emission conditions. Even at 1.5°C climate increase, previous ‘once per century’ coastal floods are expected to become annual events by 2100 in many regions.
The GEO-7 report brings together the voices of 287 experts from 82 countries, with contributions from more than 800 reviewers worldwide. This includes scientists, industry leaders and, for the first time, Indigenous and local people.
While it highlights environmental and climate challenges, it has also outlined practical pathways for action and explores future scenarios to consider and illustrate the benefits of taking proactive action.
“GEO-7 is a call to action,” said Professor John Siddorn, Chief Executive at NOC. ” The report recognises that the health of our ocean is directly related to the health of our planet and our people. It also highlights that environmental challenges will impact economies and communities alike across the globe. However, the GEO-7 also provides valuable insights into resilience, stewardship and provides an opportunity to live in harmony with the environment.”
