The rate at which oceans are currently acidifying is faster than any rate over the last 300 million years. During that time span, there were four mass extinctions researchers discovered. During those four mass extinction events, the increase in CO₂ in the atmosphere not only warmed the planet but made the oceans more acidic as well. These changes are directly linked with major climate shifts and mass extinction events.
Mass Extinction Events
In the four previous mass extinction events and CO₂ levels in the atmosphere were a result of volcanic and other naturally occurring events, however, our current atmospheric CO₂ level increases are a direct result of human activities whether deniers like it or not and may very well lead to the sixth mass extinction event.
Sixth Mass Extinction Event
In the past 100 years atmospheric CO₂ levels have risen by roughly 30% up to 393 ppm, and the pH in the oceans has fallen by 0.1 units, to 8.1, which is an acidification rate which is at least 10 times faster than 56 million years ago during the Paleocene-Eocene Thermal Maximum (PETM). To make matters worse, the Intergovernmental Panel on Climate Change (IPCC) predicts that the ocean pH levels may fall by another 0.3 units by the end of this century to a 7.8 pH, thus raising the possibility that we may soon witness changes to our oceans similar to those witnessed during the PETM.
During the PETM, this is considered by experts as one of the most intensive, abrupt intervals of global warming in geological records. The period, at the boundary between the Paleocene and Eocene epochs, was marked by a similar rapid increase in the concentration of greenhouse gases in the Earth’s atmosphere which trapped heat and drove up global temperatures by more than 5°C in just a few thousand years. Fossil records from the PETM period gives scientists the means of understanding just how life on Earth was affected by the PERM and provides an excellent opportunity to study the relationships between evolution, extinction, migration and climate change so we can better understand what is happening to our world today, and the potential risks the future holds.
According to the study’s lead author Bärbel Hönisch who is a pale-oceanographer at Columbia Universities Earth Institute Lamont-Doherty Earth Observatory:
“What we’re doing today really stands out. We know that life during past ocean acidification events was not wiped out—new species evolved to replace those that died off. But if industrial carbon emissions continue at the current pace, we may lose organisms we care about—coral reefs, oysters, salmon.”
The oceans are similar to trees in that they act like a sponge to draw down excessive CO₂ from the atmosphere, which in turn reacts with the seawater to form carbonic acid (H₂CO₃). Over a period of time, the carbonic acid is neutralized by fossil carbonate shells on the ocean floor, however, if the CO₂ is absorbed by the oceans too rapidly, it depletes the carbonate ions that corals, mollusks and some plankton need for reef and shell-building processes.
During the PETM, as discovered in an early 1990’s research project, carbonate plankton shells dissolved. It was also discovered that as many as half of all species of benthic foraminifers, a group of single cell organisms that live at the ocean bottom went extinct, suggesting that organisms higher up in the food chain may have also met the same fate according to study co-author Ellen Thomas, a pale-oceanographer at Yale University. According to Thomas:
“It’s really unusual that you lose more than 5 to 10 percent of species over less than 20,000 years. It’s usually on the order of a few percent over a million years.” During this time, scientists estimate, ocean pH—a measure of acidity–may have fallen as much as 0.45 units. (As pH falls, acidity rises.)”
Mass Extinction Events
Many critics as well as skeptics of man made climate change will point out that this is all part of our natural cycles and that there is nothing to be alarmed about, however we disagree, as does most scientists. We will grant the fact that many catastrophic events have disrupted our planet before, some much worse, however none can compare to the rapid advancement of these changes we are experiencing today which can be regarded as .rapid climate change. These events have led to mass extinction events in the past, and may very well lead to the completely man made sixth mass extinction event.
Other similar events such as the end of the Permian and Triassic periods, massive volcanic eruptions led to rapid elevations of atmospheric carbon. The Permian event led to the extinction of 96% of all marine life. In our current situation, scientists from Stony Brook University did a recent study that concluded that Acidification Of Oceans May Contribute To Global Declines of Shellfish. The scientists discovered that the rising levels of CO₂ may be contributing to the global decline of clams, scallops and other shellfish by interfering with the development of shellfish larvae.
Another recent study published in December of 2011 found that Ocean Acidification May Directly Harm Fish. Up to this point, scientists assumed that marine fish stocks were immune to the effects of ocean acidification. However in a new study, which examines the effects of CO₂ during the early development of fish eggs and larvae, which is entirely ignored by most scientists that believe fish are okay and that they are immune to the effects of CO₂. In their study they concluded:
Their present study is the first to show that elevated CO2 levels significantly decreased survival and growth rates in eggs and larvae of a fish.2 The researchers reared newly fertilized eggs of a common estuarine fish, the inland silverside (Menidia beryllina), under different CO2 levels predicted for future oceans (current: ~400 ppm3, mid-century: ~600 ppm, end-of-century: ~1,000 ppm) and found that egg and larval stages of these fish were highly sensitive to CO2. On average, survival rates until one week post-hatch declined by over 70% under elevated (1,000 ppm) compared to current day CO2 conditions. In addition, surviving larvae were 18% smaller in the high than in the low CO2 group. The experiment was fully replicated and repeated five separate times, each revealing the same pattern.
“We knew from the study of other ocean animals, such as scallops and clams, that earliest life stages such as larvae are most sensitive to CO2 and thus targeted the same life stage during our investigation of fish,” said Professor Gobler. The study thus joins a growing body of evidence, suggesting that fish will both directly and indirectly be affected by ocean acidification, which also includes the potential for decreasingly productive commercial fish stocks. Brad Warren, Science Director of Sustainable Fisheries Partnerships stated: “This study is a shot across the bow and shows that some important fish stocks may be eroded by high CO2 levels. And keep in mind, as estuarine fish, inland silversides are likely to be adapted to higher levels of CO2 than many fish found in the open ocean, where chemistry is much more stable. This suggests that many commercially harvested marine fish stocks may be vulnerable too. Pelagic spawners, such as albacore, bigeye, yellowfin, and bluefin tuna, whose larvae are not adapted to acidified waters, could be particularly vulnerable.”
This study, if it plays out like they assume it will, will greatly increase the man made sixth mass extinction no doubt. Our friends at Columbia University are also wary of the possibilities, according to the Hönisch study:
“The current rate of (mainly fossil fuel) carbon dioxide release stands out as capable of driving a combination and magnitude of ocean geochemical changes potentially unparalleled in at least the last 300 million years of Earth history, raising the possibility that we are entering an unknown territory of marine ecosystem change.”
They couldn’t be more right, as each new day we seem to be discovering untold truths about our planet and ecosystems, and that they are more fragile than we thought. This in light of the fact that others are attempting to add Climate Change Denial Curriculum In Public School Science Classrooms, which is just absurd. Are they really that profit driven, or are they just trying to hide the fact that they were the biggest contributors to our future issues from climate change in the future, and trying to rewrite history so to speak? Either way, we are at the cusp of one of the mass extinction events, as the sixth mass extinction may well be under way, and we have front row seats to the event, not to mention the fact that we are primarily responsible for it as well. This should give us all great concern and create pause for us to sit back and think “what the heck are we doing?” In any event, let us take pause and consider our moving forward, not with the reckless abandon we witnessed during the last century, but with wisdom and intelligence and not repeat the mistakes of the past. We still have a window of opportunity to avoid catastrophic rapid climate change, let us use it wisely and make the right choices! Peace my friends and Godspeed!