A preliminary report released today by an international panel of interdisciplinary marine scientists on behalf of the International Programme on the State of the Oceans gives a stark warning that unless the combined threats facing the world's ocean are not curbed soon, a marine mass extinction could occur on a scale unprecedented in human history.
"The findings are shocking," said IPSO Scientific Director Alex Rogers. "As we considered the cumulative effect of what humankind does to the ocean the implications become far worse that we had individually realized. This is a very serious situation demanding unequivocal action at every level. We are looking at consequences for humankind that will impact in our lifetime, and worse, our children's and generations beyond that."
The conclusions of the report are the product of a first-ever workshop bringing together marine experts and scientist from various disciplines to assess the latest ocean stresses and impacts, and to determine the effects of those multiple stresses on current and future ocean health. The workshop enabled these experts and scientists to engage a comprehensive, global view of the cumulative threats facing the ocean, and how they impact the future viability of ocean ecosystems.
From the report:
"This examination of synergistic threats leads to the conclusion that we have underestimated the overall risks and that the whole of marine degradation is greater tha thte sum of its parts, and that degradation is now happening at a faster rate than expected"
The preliminary report posits seven key points to "drive a common sense rethink":
- Human actions have resulted in warming and acidification of the ocean and are now causing increased hypoxia (low oxygen)
Studies of the Earth's past indicate these three symptoms (warming, acidification, hypoxia) indicate "disturbances of the carbon cycle" associated with all five previous mass extinctions on Earth. The rate of carbon absorption by the ocean is already far greater than what it was at the time of the last globally significant marine mass extinction when up to half of some marine deep-sea species where wiped out.
- The speeds of many negative changes to the ocean are near to or are tracking the worst-case scenarios from the 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
The longer we take to get serious about reducing carbon emissions, the more it will cost and the harder it will be to effectively make meaningful reductions. In the meantime, environmental damage will accrue causing greater socioeconomic impacts. The problem isn't going away.
- Resilience of the ocean to climate change impacts is severely compromised by the other stressors from human activities, including fisheries, pollution, and habitat destruction
- Ecosystem collapse is occurring as a result of both current and emerging stressors
Among those stressors are chemical pollutants, overfishing, agricultural runoff, and sediment loads.
- The extinction threat to marine species is rapidly increasing
The report cites a wholly inadequate approach to management of marine resources and activities that impact the ocean, all of which have led to "intense multiple stressors acting together in many marine ecosystems." These impacted ecosystems lack the resilience to withstand increased pressures from expanding human populations and increasing rates of CO2 emissions.
A spate of other research supports the findings of the IPSO study, all showing an ocean under severe threat, including disappearing coral reefs, rapidly increasing acidification, and growing incidences of marine life extinctions.
The IPSO report urges a change of human interaction with the ocean and adoption of a "holistic approach to sustainable management of all activities that impinge marine ecosystems."
"This has to be part of a wider re-evaluation of the core values of human society and its relationship to the natural world and the resources on which we all rely."
Sources and further reading:
Summary workshop report: International Earth system expert workshop on ocean stresses and impacts (pdf)