Recently, I read that that global CO2 levels are set to exceed the 400 ppm threshold, a sobering milestone. The Mauna Loa observatory in Hawaii is considered the gold standard for the last 50 years in carbon dioxide observation and has recorded hourly levels higher than 400 ppm several times already. We can now watch the daily readings in real time http://keelingcurve.ucsd.edu/
What does this mean? The earth is getting warmer, and has been for the last 200 years, coinciding with the beginning of the industrial revolution where levels were around 280 ppm.
What I find fascinating, is that we have a blueprint for what the earth is like with CO2 levels that high, the Late Pliocene epoch (5.3 – 2.6 million years ago, or.. never if you are a creationist). The way that we are able to discern this is through analysis of carbon isotopes of tiny marine phytoplankton preserved in ocean sediment. At that time, the sea level was around 20-40 meters higher than it is now. One of the hallmarks of the epoch was the mass extinction of coral species, something which we are already observing currently. “Our most significant finding is that a major episode of accelerated faunal turnover and extinction occurred during Plio-Pleistocene time (4-1 Ma)” –Evolution and Environment in Tropical America
Most think that the issue with CO2 is that it will create holes in the ozone layer, but that is just one of the problems – the main being ocean acidification. “Rising levels of carbon dioxide will lower the pH in the oceans, a process known as ocean acidification, and will make it difficult for corals to build their limestone skeletons.”- James Klaus, assistant professor in the Department of Geological Sciences, College of Arts and Sciences, at UM
Australian scientist Ove Hoegh-Guldberg said 26 percent of coral reefs around the world have already been destroyed and that in another 20 years, water temperatures are likely to have risen to the point where corals will be sitting in a “hot soup” and unable to survive. This is equated to losing all of the worlds rainforests at once, which themselves are already on their last legs. “I wish it weren’t true, but it looks like the world is going to blow through the 400-ppm level without losing a beat,” said Scripps geochemist Ralph Keeling, who has taken over the Keeling Curve measurement from his late father. “At this pace we’ll hit 450 ppm within a few decades.”
There is no known period in which rates of increase have been so sharp. It appears that is is already to late to do anything about it. The next global climate meeting is not until 2015.