There are a lot of devastating effects you can point to when it comes to the ravages of climate change. Floods and loss of agricultural land are often high on the list. But how is climate change impacting the world’s oceans?
A new report by leading international experts released this week, sets the record straight. The report, based on a conference that drew world scientific leaders, examines ocean stresses and impacts and concludes:
“Unless action is taken now, the consequences of our activities are at a high risk of causing, through the combined effects of climate change, overexploitation, pollution and habitat loss, the next globally significant extinction event in the ocean.”
The report looks at factors ranging from melting Arctic sea ice, greater acidification (caused by climate change) to the effects of overfishing and runoff.
Effects of such impacts include examples such as the potential increase of harmful algal blooms, spread of oxygen depleted or dead zones, disturbance of the structure and functioning of marine food webs and dramatic changes in microbial communities with negative impacts at an ecosystem scale. These all contribute to a situation that undermines the ability of ecosystems to support humans.
Extinction threat to marine species is a serious concern highlighted. Whereas overexploitation and habitat loss have been the main causes to date, climate change is becoming an increasing threat. For example, shifts in currents and temperatures will affect the food supply of animals, including at critical early stages, potentially testing their ability to survive.
Here are the key points underlying the conclusion, as presented in the report summary of conclusions and recommendations:
- human actions have resulted in warming and acidification of the oceans and are now causing increased hypoxia.
- The speeds of many negative changes to the ocean are near to or are tracking the worst-case scenarios from IPCC and other predictions. Some are as predicted, but many are faster than anticipated, and many are still accelerating.
- The magnitude of the cumulative impacts on the ocean is greater than previously understood.
- Timelines for action are shrinking.
- Resilience of the ocean to climate change impacts is severely compromised by the other stressors from human activities, including fisheries, pollution and habitat destruction.
- The extinction threat to marine species is rapidly increasing.
The report says that fundamental changes are needed to achieve a sustainable and equitable future for generations to come. They recommend actions in four areas:
- Immediate reduction in CO2 emissions
- Urgent actions to restore the structure and function of marine ecosystems
- proper and universal implement of the precautionary principle
- urgent introduction by the UN Security Council and the UN General Assembly of effective governance of the High Seas
You can read media coverage of the report here: