Marine ecosystems and fish stocks are under threat. The warming of tropical oceans is amplifying the destructive force of hurricanes and cyclones. Sea-level rise is accelerating, due in large part to the ever more rapid melting of continental ice.
WBGU chair Prof. Dr. Hans Joachim Schellnhuber leaves no doubt that the situation is serious: ‘Global CO2 emissions are continuing to rise from year to year. If the international community fails to take action immediately to halt this trend and bring about a real reduction in emissions within the next ten to fifteen years at the latest, it will be barely possible to prevent massive damage being inflicted upon the oceans as well as upon coastal regions over the coming decades.’
The oceans are acidifying worldwide because increased amounts of CO2 are being taken up by them from the atmosphere. This effect, which is already clearly measurable in seawater today, hampers the growth of calcifying organisms such as corals. Furthermore, reduced calcification can lead indirectly to worsen conditions for other marine organisms. For instance, hypoxic zones could spread in deeper water levels.
The oceans are under various additional pressures. These include over-fishing, pollution, over-fertilization, the spread of unsustainable aquaculture and the extraction of seabed resources.
The causes are several:
- There is a lack of political will to combat ocean warming and acidification rapidly and effectively.
- There is no comprehensive international strategy for sustainable ocean management.
- The present agreements in international law, especially the United Nations Convention on the Law of the Sea, are inadequate. Inefficiencies arise due to overlapping responsibilities among the institutions tasked with protecting the oceans.
In this situation, WBGU reaffirms its urgent recommendation that top priority should be given to combating climate change. If the oceans are to be conserved and used sustainably in the future, rapid and drastic reductions in greenhouse gases will be essential. This further underscores the pivotal role of the climate negotiations due to take place in Copenhagen this December.
WBGU further stresses that, in order for marine ecosystems to become more resilient to higher sea temperatures and acidification, it is crucial to protect marine resources more effectively and to manage them sustainably. One element of such efforts would be to establish a network of marine protected areas covering 20–30% of the ocean area. WBGU urges the German government to strenghten its efforts in the European Union and in international forums to achieve that goal.
Every fifth person lives less than 30 kilometres from the sea and is directly threatened by sea-level rise and storm surges. This highlights the need to improve protective and adaptive strategies at both national and international level. Such strategies will need to include plans to abandon areas at risk.
A further concern is to give legal certainty to refugees fleeing from sea-level rise. There is at present no commitment in international law to receive people forced by climate change to leave coastal areas or islands, nor is the cost issue resolved. A possible long-term solution would be to establish a quota system under which states would have to assume differentiated responsibility for refugees.
Finally, WBGU considers adjustments to existing agreements in international law (notably the United Nations Convention on the Law of the Sea) commensurate with the new challenges to be an urgent necessity.