Earth has the stamp of mankind on it, and has since the earliest people set fires to clear land or built crude dams across wild streams. Over the centuries man’s impact on the planet has grown more widespread and usually not for the better. Some recent events demonstrate that the power to shape our environment is real, and point to two possible outcomes for our stewardship of this planet. The first story is one of unexpected results and a possible acceleration of environmental collapse.
In early October the sun set on the North Pole for the last time before it appears again in the spring. In most years, that is the trigger for sea ice to freeze across the Arctic Ocean. Researchers have discovered a curious phenomenon: Starting in mid-October this year, the growth of sea ice slowed, came to a halt, then started to decrease. Apparently extreme warmth, stored in the atmosphere and ocean water, is melting the Arctic sea ice just as it should be increasing. This anomaly is occurring even earlier than last year, when temperatures spiked in December, months after the usual freeze had set in.
Climate change is creating a new set of records that underscore the steady and undeniable impact of man’s activities on global climate: Maximum sea ice extent has been at its lowest for two years in a row, and each of the three preceding years saw a record for the hottest average global temperature. This year’s Arctic Ocean October Surprise already has had direct and measurable effects, and the sea ice is missing a chunk of ice roughly one-fourth the size of the lower 48 states. Even into November, scientists recorded air temperatures as high as 36 degrees Fahrenheit above normal. In spite of the lack of sunlight, sea ice continued to disappear. Water temperatures on the edge of the sea ice are above normal in many locations, further hindering the growth of sea ice.
The nature of ice that is in place has also changed over time. Detailed measurements and ice cores kept since the 1980s confirm “old ice” is mostly gone, and most of the ice pack is now “young ice” accumulated in the last few years. This young ice is likely to be more brittle and prone to breakup and melting when confronted with extreme warmth. And where is this warmth coming from? Most directly, convection currents in the atmosphere created large troughs and ridges. In mid-October the eastern edge of one of these troughs settled over northeast Asia, creating a strong surface low that channeled warm air at the surface across the Bering Strait. A similar low developed over the North Atlantic, creating another conduit for warm air to funnel into the Arctic.
The inability of the sea ice to freeze to its previous extent created a feedback loop that is accelerating the warming and melting process. In the summer, the Arctic Ocean’s dark open water absorbed the sun’s energy much more readily than sea ice, which reflects much of the energy back into space. This process not only slowed freezing, it also warmed and moistened the air. The result was excessive water vapor — a greenhouse gas that tends to create more clouds and trap heat near the ocean surface. At one time, the warming trend in the Arctic led to predictions of ice-free summers by the year 2050; some researcher now estimate that ice-free summers may be the norm as soon as the 2030s. Climate researchers, in near unanimity, identify the primary driver of these changes as man-made carbon pollution, which serves to heat the planet through greenhouse gas creation on a global scale.
A second story points to an alternate future where man’s intervention may actually improve the environment. In 1970, Bruce McDuffie, a chemistry professor at the State University of New York at Binghamton, discovered levels of .75 parts per million of mercury in cans of tuna taken from supermarket shelves. This level of mercury, which can cause blindness, nerve and brain damage and even death, exceeded by 50 percent the limits set by the U.S. Food and Drug Administration (FDA). Shortly thereafter McDuffie announced finding even higher concentrations of mercury in swordfish. The FDA confirmed the reports, and the world fishing market went into turmoil, ultimately withdrawing hundreds of thousands of dollars of tuna and swordfish from the market.
In a positive turn, a recent study indicates that levels of mercury in Atlantic Bluefin tuna are rapidly declining, falling 19 percent in the period from 2004 to 2012. The report links the decline directly to reduced mercury emissions in North America, due mainly to the shift by power plants and industry away from coal, the major source of mercury emissions, as well as pollution control requirements imposed by the Environmental Protection Agency (EPA). This news is tempered by the fact that worldwide mercury emissions continue to rise, particularly in the Pacific, increasing about 3.8 percent per year, based largely on increased reliance on coal-fired power plants in China, India and other Asian countries.
Still, the decrease in Bluefin mercury levels is an encouraging sign that shifting away from highly polluting energy sources and following regulations targeted at improving the environment can lead to positive results in a relatively short amount of time. Most importantly it offers some hope that man’s hands can heal, as well as harm, this planet, our only home and hope for the foreseeable future.
