Is the Great Barrier Reef on Death Row?

An extract from the public presentation, by Prof. J.E.N. Veron, with an introduction by Sir David Attenborough, which took place Monday afternoon at the Royal Society, London. I attended the presentation, which was followed by a summary of a statement produced by the technical expert workshop held in the morning. Above is a photo I took during the event questions session, showing Sir David Attenborough on the left and Prof. Veron on the right.

In his introduction to the presentation Sir David Attenborough started by saying ‘we all think we know coral reefs, we have seen it on the telly.’ He introduced Prof. Veron, who he said has the best job in the world - swimming and studying the most beautiful reefs in the world and pointed out he produced the definitive catalogue of reefs in the world. During his research life he discovered that coral reefs are dying and that things will get worse as CO₂ emissions increase. Sir David ended his introduction by saying we hear a lot about the impact of global warming on the environment second hand in the media, but today we are privileged to hear about coral reefs first hand from the world’s authority on coral reefs.

Prof Veron started the presentation entitled ‘Is the Great Barrier Reef on Death Row’ with a background on corals. Coral reefs are unique. They exist at an interface of the atmosphere and the ocean. They are geological structures very closely attuned to their environment and they are very particular about light, temperature and carbonate chemistry of the ocean. Reefs are nature’s historians; they are made of limestone and so are preserved in fossils; every fossil is a book of the environment that existed.

He also discussed the history of coral reefs mass extinction from the Ordovian, millions of years ago, to today, showing that extinction happened in each era and the reefs managed to reform themselves. Carbon dioxide concentrations in the atmosphere went up and down over each era, but only now it has been linked to coral reefs mass extinction, which coincided with periods of high CO₂ in the atmosphere. However, corals are very good at recovering from mass bleaching in a matter of a few months (from rubble to reef), but only if the water quality in their environment is good.

Bleaching started happening recently in the early 1980s and the effects increase with increased CO₂ concentration in the atmosphere, since the oceans absorb 1/3 of the CO₂ we produce. The effects of increasing CO₂ concentration on coral reefs were shown and are as follow:

• 320 ppm  - not much effect
• 350 ppm - periodic bleaching
• 387 ppm (current level) - compound long-term degradation
• 400 ppm (target for year 2015) - will cause severe bleaching
• 450 ppm - severe bleaching most years
• 500 ppm - will cause bleaching every year, if there are any coral reefs left.
  

The morning technical workshop meeting group, which included marine scientists and climate change experts produced a statement, which concluded that at today’s CO₂ levels of 387 ppm reefs are seriously declining. Proposals to limit CO₂ levels to 450 ppm will not prevent catastrophic loss of corals, and other human impacts will prevent coral reefs from recovering. This is just a brief summary of the statement, which contains many more recommendations in more detail.

This link to the statement was just emailed to me by Prof. Veron, as I was writing this blog.

All the participants of the workshop and the presentation audience signed the statement, which is going to be sent to Copenhagen before the December meeting of the UNFCCC and Kyoto protocol parties.

Many other ocean life forms are affected by mass bleaching, but it’s only the coral habitat that is lost. Coral reefs loss will also result in large economic losses from tourism and, more importantly, a loss to a large section of the population mainly in developing countries, who depended on coral reefs for food and their livelihoods. 

Link to Prof. Veron’s research site: Coral Reefs and Climate Change