Saturday 11 October 2014

Ocean acidification

We are Looking at the Complete Loss of Tropical Coral Reefs By 2050 to 2100

Ecosystems that have thrived and developed over millions of years are being smashed down by human activities in just a few decades. It is a very sad state of affairs that hopefully we can turn around before it is too late.”
Ken Caldeira of Stanford University.



9 October, 2014

One trillion dollars. That’s the economic impact a new UN study found resulting from the world’s oceans becoming 170 percent more acidic by 2100 under an inexorable and ongoing human carbon emission.
It’s a rapidly ramping acidity that is being driven by an ever-rising level of CO2 in the Earth’s atmosphere. An emission that is already setting the stage for a first wave of mass extinction in the world ocean — starting now and hitting high gear once global CO2 levels reach about 500 parts per million (this year, global CO2 levels topped off at 401 parts per million and under current and planned emissions are likely to hit 500 ppm within about 30 years).
At issue is the vulnerability of coral reefs and many other species with calcareous skeletons and shells to rapid acidification. In the deep geological past, we’ve seen mass extinctions in many of these species due to rapid rises in ocean acidity. Events such as the Permian and PETM extinctions all showed terrible losses of species due to ocean acidification alone.
But the pace at which humans are increasing ocean acidification has never been seen before in the geological record. So the blow that is coming to many of the animals we rely on is worse than anything witnessed in Earth’s deep past.

Ocean Acification Through 2050
(Ocean acidification and related impacts to coral reefs through 2050 [500 ppm CO2]. Bands in the marginal and extremely marginal range represent acidity levels in which reefs struggle to survive. Image source: Threat to Coral Reefs From Ocean Acidification.)

Recent studies have provided numerous highlights to the extraordinary risks posed to coral reefs over the coming decades. One study, published in 2011, called into question the reefs’ ability to survive even through to the 2050 timeframe. A sudden loss that would be both staggering and unconscionable.

The reefs themselves are home to more than a million species — all of whom provide untold and priceless benefits to the Earth and to human beings alike. The reefs also provide broad support for worldwide fishing and tourism industries. Without the reefs both a critical life support and a key support to human civilization simply dissolves.
It’s callous to put a price on such an egregious loss. But behind the massive 1 trillion dollars in economic damages we can glimpse a world that has also lost a great portion of its beauty and vitality. Imagine a world barren and bereft of the living jeweled belt of coral reefs. Imagine desertified oceans, leeched of life as a result. Such a loss is unconscionable. Like witnessing a holocaust of wonder.
A stark example of the terrible life, wealth and beauty destruction engine that is human-driven climate change.
But that’s what we can look for as ocean PH levels spiral from 8.1 during the 1880s to 8.0 now to 7.9 by or before 2100.
The study did not assess the added damage also ongoing throughout the world due to rapid ocean warming, resulting in widespread coral bleaching. A major instance of which is now ongoing in Hawaii due to dangerous ocean temperatures in excess of 86 degrees Fahrenheit.
In order to prevent a rise of global CO2 levels to 500 parts per million, we must begin rapidly shutting down global fossil fuel infrastructure. This includes all emitting infrastructure — coal, oil, or natural gas. Shutting down coal plants is a good start, but building gas plants to replace them still results in an easy overshoot of the 500 ppm level.
Links:
(Hat Tip to Colorado Bob)

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