EGU Position Statement on Ocean Acidification

”Impacts of ocean acidification may be just as dramatic as those of global warming (resulting from anthropogenic activities on top of natural variability) and the combination of both are likely to exacerbate consequences, resulting in potentially profound changes throughout marine ecosystems and in the services that they provide to humankind”.

1/5 of coral reefs already lost, much more feared

The world has lost nearly one-fifth of its coral reefs and much of the rest could be destroyed by increasingly acidic seas if climate change continues unchecked, an environmental group warned Wednesday.

Global warming and the rising temperature of the oceans are the latest and most serious threats to coral, already damaged by destructive fishing methods and pollution, the International Union for Conservation of Nature said.

“The world has lost about 19 percent of its coral reefs during the last 20 years,” said IUCN’s director general, Julia Marton-Lefevre, on the sidelines of the 190-nation U.N. talks on a new climate change treaty.

“If current trends in carbon dioxide emission continue, many of the remaining reefs will be lost in the next 20 to 40 years,” she told reporters.

Fifth of world’s corals already dead, say experts

Almost a fifth of the planet’s coral reefs have died and carbon emissions are largely to blame, according to an NGO study released Wednesday.

The report, released by the Global Coral Reef Monitoring Network, warned that on current trends, growing levels of greenhouse gases will destroy many of the remaining reefs over the next 20 to 40 years.

“If nothing is done to substantially cut emissions, we could effectively lose coral reefs as we know them, with major coral extinctions,” said Clive Wilkinson, the organisation’s coordinator.

Fifth of Corals Are Dead, CO2 Destroys Ocean Habitat

One-fifth of the world’s corals have died and many remaining reefs may be lost by 2050 as carbon dioxide from cars and pollution-spewing industries make ocean water warmer and more acidic, the Global Coral Reef Monitoring Network said.

While natural disasters such as the earthquake that set off the Indian Ocean tsunami in 2004 killed some reefs instantly by forcing them out of the water, seas made warmer by heat-trapping CO2 gas is the biggest threat to corals, said the report from the International Union for Conservation of Nature. The Gland, Switzerland-based group is one of eight that manages the network.

The study was released as delegates from about 190 nations are meeting in Poland to lay the groundwork for a new treaty to fight global warming that is due to be signed a year from now in Copenhagen. The report shows that to sustain corals, CO2 emissions as well as damage from human activities must be kept to a minimum, said Clive Wilkinson, coordinator of the monitoring network.

“If nothing is done to substantially cut emissions, we could effectively lose coral reefs as we know them, with major coral extinctions,” Wilkinson said in the report.

Time Running Out On Coral Reefs As Climate Change Becomes Increasing Threat

Increasing pressures from climate change will reach a tipping point in less than a decade triggering a significant decline in the health of the planet’s coral reef ecosystems according to the findings in an international report.

Released by the Global Coral Reef Monitoring Network and the International Coral Reef Initiative, international governmental and scientific partnerships, “Status of Coral Reefs of the World: 2008″ provides both good and bad news while sounding the call for urgent global action to respond to climate change.

Coral reefs continue to be threatened from direct human activities of pollution and over-fishing, but now the threat of climate change is being recognized as the major threat to the future of reefs around the world. One fifth of the Earth’s coral reefs have disappeared since 1950, and a NOAA authored report issued in July states that more that that nearly half of U.S. coral reef ecosystems are considered to be in “poor” or “fair” condition.

“Unless the world gets serious about reducing greenhouse gas emissions in the next few years, it is likely there will be massive bleaching and deaths of corals around the world,” notes the report’s lead editor and global coral authority Clive Wilkinson who coordinates the Global Coral Monitoring Network in Australia. “This will have significant impacts on the lives of the people in developing countries who are dependent on reefs for food, for tourism, and for protecting the land they live on.”

Evidence for a multi-species coccolith volume change over the past two centuries: understanding a potential ocean acidification response

Major questions surround the species-specific nature of coccolithophore calcification in response to rising atmospheric CO2 levels. Here we present CaCO3 particle volume distribution data from the coccolith size-fraction of a rapidly accumulating North Atlantic sediment core. Without direct volume measurements on coccoliths produced by individual coccolithophore species, and knowledge of organic, as well as inorganic carbon production, it is not possible to state conclusively the coccolithophore calcification change at this site. However, by analysing the size distribution of CaCO3 particles in the less than 10 μm sediment fraction, we demonstrate a changing particle volume since the late 20th Century consistent with an increase in the mass of coccoliths produced by the larger coccolithophore species, and potentially a decrease in mass of coccoliths produced by the smaller species, present at this location. This finding has significant implications for the realistic representation of an assemblage-wide coccolithophore CO2-calcification response in numerical models.