PARIS: Humanitymust heal oceans made sick by climate change and pollution to protect marinelife and to save itself, experts warned days before the release of a major UNreport. By absorbing a quarter of manmade CO2 and soaking up more than 90percent of the heat generated by greenhouse gases, oceans keep the populationalive - but at a terrible cost, according to a draft of the IntergovernmentalPanel for Climate Change (IPCC) assessment seen by AFP.
Seas have grownacidic, potentially undermining their capacity to draw down CO2. Warmer surfacewater has expanded the force and range of deadly tropical storms. Marineheatwaves are wiping out coral reefs, and accelerating the melt-off of glaciersand ice sheets driving sea level rise.
"The lastbook of the Bible talks about the four horseman of the Apocalypse," saidDan Laffoley, strategic lead for ocean protection at the International Unionfor the Conservation of Nature. "For the oceans, the lead horseman issurface warming," he told AFP. "The three others are ocean heating,loss of oxygen and acidification." There are at least three types ofactions humans can take to help repair the damage and ensure that oceans don't turnfrom friend to foe, scientists say.
Restoration,Protection
Less than sevenpercent of oceans - which cover 70 percent of Earth's surface - benefit fromsome form of regional or national protection, often with minimal enforcement.Ocean advocates and experts say the area safeguarded must be vastly expanded."We need to protect 30 percent of the ocean by 2030," said LisaSpeer, director of the international oceans program at the National ResourcesDefense Council in Washington DC. "This cannot be achieved without a highseas agreement," she added. UN negotiations for a treaty to regulateexploitation of the high seas - waters beyond national jurisdiction coveringnearly half the planet - began last fall, and could take years to complete.
At the same time,regions not included in marine parks or conservation areas "must bemanaged in a cautious and durable way," Tom Dillon, Vice President of PewCharitable Trust said. Restoring coastal mangroves and seagrass meadows,meanwhile, would draw down CO2 emissions, and shield coastal communities fromstorm surges as a bonus. These "blue carbon" ecosystems couldpotentially stock just under a billion tons of CO2 per year, about two percentof current emissions, according to the UN report.
Renewable energy
Off-shore andocean-based renewable energy - including wind, wave, tidal, currents and solar- could meet a significant slice of future energy demand, numerous studies haveshown. Such schemes are mostly experimental and thus costly per unit of energygenerated, but economies-of-scale are possible. Floating wind farms, forexample, fuelled by high wind speed over the open ocean could eventuallygenerate more electricity than those on land, Carnegie Institution for Scienceresearchers reported in PNAS.
In winter, NorthAtlantic wind farms "could provide sufficient energy to meet all ofcivilization's current needs," the authors said. "That's a bit offantasy, but it makes the point that these technologies have not beensufficiently developed," said Jean-Pierre Gattuso, a senior scientist atFrance's National Centre for Scientific Research. There are several ready to bescaled up, he said.
Geoengineering
The failure ofhumanity to draw down planet-warming greenhouse gases - which continue to riseyear-on-year - has opened the door to other ideas once thought risky orfar-fetched, such as injecting particles into the upper atmosphere to deflectthe Sun's radiation. Some geoengineeringschemes to cool Earth's surface or reduce CO2 are ocean-based. One that has beentested with inconclusive results involves sowing the open ocean with iron tocreate phytoplankton colonies that absorb CO2 as they photosynthesise. When thetiny creatures die, they drag the CO2 into the inky depths.
Another schemewould brighten mirror-like marine clouds to reflect sunlight back into space.Spreading long-lasting white foam across vast expanses of open water would - intheory - have the same effect. Scientists from Princeton and Beijing NormalUniversity recently costed a plan to build an underwater barrier in front of anAntarctic glacier the size of England to help prevent warm ocean water fromeroding its underbelly, thus preventing the glacier from slipping into the sea.The price tag was several hundred billion dollars. - AFP