The Ocean Rules Climate … Climate Rules the Ocean
The ocean is the engine that drives our planet’s climate. It is our life support system, providing much of the air we breathe, the food we eat, and the resources we depend on for life every day. The ocean is essential for life. 

Unfortunately, the ocean will be the first ecosystem to suffer widespread effects of global climate change. Increasing levels of carbon dioxide and other greenhouse gases pose major threats to our ocean as well as our atmosphere. Widespread effects brought on by higher air and water temperatures include loss of sea ice, sea level rise, extreme weather events, and harmful changes to marine fish and wildlife populations. Increased concentrations of carbon dioxide will lead to acidification of ocean water, threatening many ocean organisms, particularly corals and important species at the base of the ocean food web.

The picture is grim, but ultimately, this is a message of hope because the will to act and the solutions are the products of knowledge. It is not too late to act. The big question remains will our federal government provide the vision and leadership we need, or will that role fall to the States and world leaders?

Ocean Conservancy has documented here a few of the most serious consequences of global warming for the ocean.

A Warmer Ocean
The ocean has absorbed over 80% of the excess heat produced by the greenhouse effect and roughly half of the carbon dioxide (CO2) we have pumped into the sky. Consequently, the ocean has warmed steadily over the last 50 years, especially at the surface. This has led to the melting of polar ice, rising sea level, loss of coastal habitats, coral bleaching, and a likely increase in the intensity of hurricanes. These are but a few of the serious consequences for the ocean.  The atmosphere has warmed at an average of 1.4ºF since 1850 (the industrial era).  This change sounds insignificant, but we are learning through killer heat waves, extended droughts, and disappearing glaciers just how significant slight but widespread changes can be to our planet.  Climate models predict a further warming of 1ºF by the end of the century will intensify these impacts, likely leading to extinctions of sensitive plants and animals, biodiversity losses and a decrease in our ecosystems’ ability to adapt to change. And, this is if we hold to year-2000 CO2 levels—a goal we are far from reaching.  Warming in the range of 3-7ºF, which is predicted to occur if we do nothing to reduce emissions, could produce the widespread extinction of large numbers of species, the severe alteration or collapse of ecosystems, and devastating impacts on humans, especially the poor.

Melting Ice
It seems counterintuitive but Arctic air temperatures have increased at almost twice the rate of the rest of the world.  Climate change effects are expected to be greater here and to occur more rapidly than anywhere else. Each year, as summer reigns in the Arctic, the ice cap that covers the North Pole recedes and then, like the tides, begins to expand again as the sun disappears for the winter. Since 1979, scientists have measured the extent of the Arctic ice cap at its summer low-point. In 2005 the extent of sea-ice was 20% lower than 1979—a troubling trend, to be sure.  Just two years later, in 2007, the cap receded to a level 43% lower than the 1979 measurement—a rate that startled everyone, including scientists. If this trend continues, the North Pole could be entirely devoid of summer sea ice by 2050. If the large land-based ice sheets of Antarctica and Greenland melt completely, as predicted by some climate models, the ocean could rise by over 20 feet.

Threats to Ocean Life
Animals such polar bears, seals and walrus depend on the sea-ice habitat for hunting and places to reproduce.  The effect of ice loss on such wildlife could be catastrophic. Impacts on these species are already being felt. If the ice cap vanishes, conservative predictions show a loss of two-thirds of all polar bears by 2050.  In addition to sea-ice, land-based ice sheets and glaciers are melting or breaking up, altering the salinity of coastal waters, changing habitats critical for wildlife, and affecting the distribution of marine wildlife, among other serious consequences.  The human inhabitants of the Arctic are acutely aware of the profound changes occurring in their world that are already altering their way of life and ability to sustain their communities. In the tropics, climate change is accelerating the destruction of coral reefs and other sensitive systems, eliminating the myriad animal life there.

A Rising Sea
Melting land-based ice and the natural expansion of seawater as it warms, are causing sea level to rise.  At present, the rise is just millimeters per year, but it is increasing.  In time, the seas will override coastal lands, severely impacting communities, destroying wetlands, pushing seawater into fresh and damaging habitats critical for wildlife.  Should the ice sheets of Antarctica and Greenland melt completely, as predicted by some climate models, the world would lose valuable lands and infrastructure. Much of the state of Florida, the fertile mega-deltas of Africa and Asia, and many small oceanic islands would be swamped, permanently displacing millions of people and inundating important agricultural lands.

Acidifying Seawater
The ocean absorbs much of the carbon dioxide from the air, taking in half of all CO2 emitted by human activity—far more than all the rain forests on Earth combined.  Without this process the atmosphere would be much warmer today, and we on land would be suffering much more.   The absorption of CO2 has increased the acidity at the ocean surface, limiting availability of the calcium carbonate essential to coral, plankton that contribute to ocean productivity, and other marine life that need it to build the skeletal structures or shells that provide them protection.  Scientific studies suggest that these organisms are already suffering reduced growth rates.  Unchecked, ocean acidification could one day make seawater so corrosive to these organisms that their protective structures will dissolve in the very water in which they live. Some researchers believe ocean acidification to be a greater threat to the ocean than warming.

Retreating Coral Reefs
Ocean warming is causing longer and more frequent extreme temperature events in the tropics where coral occur. Coral are extremely sensitive to high water temperatures and when water temperature rises—even slightly—coral polyps expel their symbiotic algae, resulting in a whitening known as ‘coral bleaching.’  If the rise persists, the corals die.  Bleaching events have grown in number and size since the 1980s. In 1998 alone, bleaching killed an estimated 16% of all the world’s corals. In addition to bleaching, coral reefs suffer from pollution, nutrient runoff, overfishing and now, acidification.  Each of these multiple impacts reduces the ability of coral reefs to withstand the damaging effects of the others, making the future for coral reefs very bleak In recent decades. A global assesment of coral species in 2008 concluded that one-third of coral species have a high risk of extinction in the near future.

Ecosystems on the Move
Changes in ocean temperature, ice cover, circulation, and salinity are already causing plant and animal populations to change size, species to shift their geographic range, and enhancing the spread of invasive species. These effects will alter the character and functioning of ocean ecosystems, and, thus, impact human communities and economies that rely upon the ocean.   Ecosystems are naturally resilient to stress, but the increases in CO2, acidity and temperature—all at levels not seen for hundreds, thousands and, in some cases millions, of years—may be too much. The speed at which these changes are occurring, and the compounding effect of multiple other stresses, like pollution and overfishing, may lead to altered states or outright ecosystem collapse.

Storms Intensifying
As the Ocean continues to warm, the duration and intensity of hurricanes is predicted to increase, which is no surprise to those who live in New Orleans. When more intense storms strike land coastal habitats and communities will suffer significant losses. Hurricane Katrina may have been an early glimpse of the future for the Caribbean and Gulf of Mexico, where many scientists believe there has been a significant increase in violent storms since the 1970s.

Climate Change Accelerating
As if all this wasn’t enough, the very latest research shows more rapid increases in CO2, losses of Arctic sea ice, breakup of Antarctic ice shelves, ocean acidification, coral bleaching, and on and on… than were predicted just a short time ago. Research published in November 2007 documented a surprising acceleration in atmospheric CO2, driven by economic growth and the deterioration of carbon absorption on land and in the ocean. It appears that the vast Southern Ocean may be saturated with CO2 and unable to absorb as much as it once did. Another study from the same time, shows that rising acidity is happening faster in the Southern Ocean where it could negatively affect the plankton that are critical to removing CO2 from the atmosphere, further compromising the seawater’s already reduced ability to absorb CO2. In terms of the melting Arctic ice cap, scientists recently thought it would take a century or more for the Arctic ice cap to disappear, but the timeframe is now estimated in decades. One researcher has even projected its loss in less than 10 years.

Solutions: A Ray of Hope
Can we do anything to avoid or at least reduce the impacts of climate change? The answer is yes … but not completely.  Damaging change is now occurring and it will likely get worse in the near term. Even if we were to immediately cap CO2 emissions at today’s level, warming would continue.  Our response, therefore, must include mitigation strategies that substantially reduce greenhouse gas emissions through changes in energy policy and use (e.g., use less energy and find alternatives to fossil fuels), and in land use (e.g., reduce the burning of forests).  Other proven methods, such as reforestation, hold the promise of enhancing the absorption of CO2 from the atmosphere. Reducing other stresses on marine ecosystems  such as pollution, habitat destruction and overfishing will increase ecosystem resilience, improving the ocean’s ability to resist and recover from the effects of climate change. These responses are required of the developed and developing worlds.  Regardless of what we do, we will have to adapt to some degree of change. It is inevitable.  Adaptation offers the great hope that we can adjust to and minimize the negative impacts of climate change and use our technological acumen to build a more sustainable society.  It is not too late, but, if we want to secure an acceptable future for our grandchildren, we must undertake these difficult steps toward mitigation and adaptation now.