Climate deal may be too late to save coral reefs, scientists
warn  Plight of the coral reefs reefs including the Great
Barrier Reef off Australia could begin to break up within a few
decades, research suggests. Photograph: Cathie Page
Carbon dioxide in the atmosphere has risen from 280 parts per
million (ppm) before the industrial revolution to more than
380ppm now. Campaigners and politicians in Europe and the UK say
a new global climate deal, which is expected to be agreed next
year, must aim to limit CO2 to 450ppm, though scientists say
that is unlikely and the world is heading for 550ppm or even
650ppm.  The research suggests that stabilising world carbon
levels at 450ppm would still dump so much carbon dioxide in the
oceans that only 8% of coral reefs would be surrounded by water
with enough aragonite to maintain their structure. Some 7% of
the ocean below 60 degrees south will see a shortage of
aragonite, while parts of the high latitude ocean could see a pH
drop of 0.2 units.  At 550ppm CO2 in t