Understanding Global Climate Change
Ocean Acidification, Ocean Temperature


Ocean Acidification: The Other CO2 Problem

  Ocean acidification (OA) is the quiet tsunami of
  environmental degradation. Within a few decades, OA may
  devastate some marine ecosystems and threaten the
  productivity of our fisheries. When we burn oil, coal, or
  gas, scientists have recently shown, we are transforming the
  fundamental chemistry of the oceans, rapidly making the
  water more acidic.

Ocean acidification


  For more than 200 years, or since the industrial revolution
  began, the concentration of carbon dioxide (CO2) in the
  atmosphere has increased due to the burning of fossil fuels
  and land use change (e.g. increased car emissions and
  deforestation). During this time, the pH of surface ocean
  waters has fallen by 0.1 pH units. The pH scale, like the
  Richter scale, is logarithmic, so this change represents
  approximately a 30 percent increase in acidity.

  The ocean absorbs about 30% of the CO2 that is released in
  the atmosphere, and as levels of atmospheric CO2 increase,
  so do the levels in the ocean. When CO2 is absorbed by
  seawater, a series of chemical reactions occur resulting in
  the increased concentration of hydrogen ions. This increase
  causes the seawater to become more acidic and causes
  carbonate ions to be relatively less abundant.

Covering Ocean Acidification: Chemistry and Considerations

An Upwelling Crisis: Ocean Acidification

TED Talk (18+ Minutes)
Rob Dunbar: Discovering Ancient Climates in Oceans and Ice

  Rob Dunbar hunts for data on our climate from 12,000 years
  ago, finding clues inside ancient seabeds and corals and
  inside ice sheets. His work is vital in setting baselines
  for fixing our current climate -- and in tracking the rise
  of deadly ocean acidification.

Ocean acidification on track to be among the worst of the last
300 million years

  A new paper in Science examines the geologic record for
  context relating to ocean acidification, a lowering of the
  pH driven by the increased concentration of carbon dioxide
  in the atmosphere. The research group (twenty-one scientists
  from nearly as many different universities) reviewed the
  evidence from past known or suspected intervals of ocean
  acidification. The work provides perspective on the current
  trend as well as the potential consequences. They find that
  the current rate of ocean acidification puts us on a track
  that, if continued, would likely be unprecedented in last
  300 million years.

  The authors conclude, "The current rate of (mainly fossil
  fuel) CO2 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."

Greenhouse emissions similar to today's may have triggered
massive temperature rise in Earth's past

  About 55.5 million years ago, a burst of carbon dioxide
  raised Earth's temperature 5C to 8C, which had major
  impacts on numerous species of plants and wildlife.
  Scientists analyzing ancient soil samples now say a previous
  burst of the greenhouse gas preceded this event, known as
  the Paleocene-Eocene thermal maximum (PETM), and probably
  triggered it. Moreover, they believe humans are pumping
  similar levels of carbon dioxide into the atmosphere right
  now, raising concerns that our own emissions may also
  destabilize Earth's climate, triggering the planet to emit
  devastating bursts of carbon in the future.

NOVA scienceNOW | Mass Extinction (13+ Minutes)
  Host Neil deGrasse Tyson joins a team of investigators hot
  on the trail of a mass murderer--one that knocked off its
  victims 252 million years ago when it wiped out the majority
  of life on our planet.

Five mass extictions--and what we can learn from them

  So, are we currently in the middle of a mass extinction? If
  we really are, this time the cause is not a meteorite impact
  or volcanic eruptions. It is the work of a single species:
  Homo sapiens. Habitat destruction and climate change from
  rising carbon dioxide levels has driven extinction rates to
  levels reminiscent of the mass extinctions of the ancient

  The similarities between today and the past are uncanny. The
  majority of past extinctions are associated with carbon
  dioxide from volcanoes causing rapid global warming, which
  led to a number of environmental cascade effects. The cause
  may be different, but the results will be the same.

Mass Extinction in Earth's Oceans Could Begin by 2100

  The amount of carbon in our planet's oceans has varied
  slowly over the ages. But 31 times in the past 542 million
  years the carbon level has deviated either much more than
  normal or much faster than usual. Each of the five great
  mass extinctions occurred during the same time as the most
  extreme carbon events. In each case, more than 75 percent of
  marine animal species vanished. Earth may enter a similar
  danger zone soon.