By Lara Levison
“Human influence on the climate system is clear, and recent anthropogenic emissions of greenhouse gases are the highest in history. Recent climate changes have had widespread impacts on human and natural systems.”
This seemingly mild statement opens the November 1 report issued by the international committee of scientists charged with assessing climate change science. In fact, although the report is written in an academic style, it is clear that the 800 plus scientists who wrote it are deeply alarmed by the climate challenge facing humanity. Some major points from the Intergovernmental Panel on Climate Change (IPCC)—rephrased in our words—include the following:
- Climate change is happening now—not in some distant future time. Really.
- There is no doubt that human activities are warming the Earth’s climate.
- Concentrations of carbon dioxide pollution are the highest in at least 800,000 years—since long before modern humans walked the earth.
- Climate deniers’ claims that the climate hasn’t warmed in the past 15 years are hogwash.
- Climate change is impacting human society and ecosystems around the world, on all continents and the oceans.
- People who are already disadvantaged are at greater risk, and one of the big risks is starvation.
- A large number of species face extinction due to climate change.
- Aggressive action now to curb carbon pollution can still save us from disaster.
The report includes quite a few specifics about what climate change means for our oceans:
- Between 1971 and 2010, more than 90 percent of the warming was stored in the global ocean, especially near the surface.
- Ocean warming will continue, especially on the ocean surface in the tropical and Northern Hemisphere subtropical regions.
- Since the beginning of the industrial era (1750), the ocean has absorbed about 30 percent of the carbon pollution added to the atmosphere by human activities.
- As a result, the ocean has become 26 percent more acidic, and will become increasingly more acidic in the future.
- Arctic sea ice has decreased in every season and in every decade since 1979.
- Since 1901, sea level globally has risen 7.5 inches, though local rates of sea level rise vary.
- Marine organisms will face lower oxygen levels, high rates of ocean acidification, and greater temperature extremes, with coral reefs and polar ecosystems highly vulnerable.
- Reduced productivity of fisheries will undermine food security for many people.
The scientists have rang the bell for action. Many of the climate change impacts, including sea level rise, are now irreversible and will continue for centuries. But the greatest risks can be averted by deep reductions in greenhouse gas emissions over the next several decades. This is referred to as climate change “mitigation”. To have a decent chance of keeping global warming below 2 degrees Celsius worldwide, emissions need to go down 40 to 70 percent by 2050, compared to 2010 levels, and drop to around zero by the end of the century. Measures to assist communities and natural systems to adapt to climate change also reduce the risks.
At Oceana, our campaigns dovetail with both mitigation and adaptation strategies. We oppose expanding oil and gas drilling into the Arctic and Atlantic oceans off our coasts, and we promote development of wind farms off the Atlantic coast to provide clean, renewable energy to our communities. We promote sustainable fisheries in the U.S. and abroad, because healthy sustainable fish populations can better adapt to climate change—and help feed people around the world who may otherwise face food shortages due to population growth and climate change. Click here to learn more about Oceana’s work.