Creating an Ecological Society. Chris Williams
in December 2015 by world leaders from 194 countries and the European Union, states that human-caused climate change represents “an urgent and potentially irreversible threat to human societies and the planet” that will require “deep reductions in global emissions.” The agreement notes “with serious concern” the “significant gap between the aggregate effect of Parties’ mitigation pledges in terms of global annual emissions of greenhouse gases by 2020 and aggregate emission pathways consistent with holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels.”14
The agreement goes on: “Parties should, when taking action to address climate change, respect, promote and consider their respective obligations on human rights, the right to health, the rights of indigenous peoples, local communities, migrants, children, persons with disabilities and people in vulnerable situations and the right to development, as well as gender equality, empowerment of women and intergenerational equity.”15 Currently there is no mechanism in place to achieve these lofty—and urgently necessary—objectives.
Based on temperature records dating back to the nineteenth century, 2016 was the third year in a row to set a global temperature record. Compared to the base period of 1880-1920, the earth was warmer in 2016 by an average of 2.27°F (1.26°C), a level last seen over 100,000 years ago.16 Even if we stopped all production of fossil fuels right now, today, we are already locked in to at least another 1.8°F (1°C) of average warming. The amount of warming guaranteed if the Parties to the 2015 Paris Agreement do everything they say they’re going to, will put the world on track for a truly catastrophic warming of up to 7.2°F (4°C), warmer than the planet has ever been during our existence as a species. Scientists have estimated that the extra energy we have been putting into the atmosphere since 1998, by trapping more greenhouse gases, is equivalent to exploding four atomic bombs every second—over two billion nuclear detonations.17
The last time that global temperatures dropped below the twentieth-century average was February 1986. And the record heat of 2016 brought the world within touching distance of the 1.5°C maximal limit declared dangerous at the Paris meeting the previous year. As of September 2016, eleven of the twelve previous months had set monthly high temperature records. July 2016 set a record for the warmest month ever recorded and then August tied the record.
Such rapid warming of the land and sea is devastating, particularly as it combines with other impacts and leads to further instability and detrimental cumulative effects. The significance of turtles to humans and to the integrity of the ecosystem goes beyond their contribution to human culture and how they are simultaneously threatened by that culture. They are also natural predators of jellyfish, helping to keep their populations in check. As drift animals, jellyfish are swept into every ocean, and the gigantic leatherbacks migrate over vast oceanic distances to chase their prey. Since jellyfish are almost all water and not much protein, leatherbacks must eat huge quantities of jellyfish to stay alive. One study reports that in a single day leatherbacks eat 73 percent of their body mass in jellyfish, an amount that equates to several hundred lion’s mane jellyfish per turtle.18 With leatherbacks driven to near extinction, jellyfish populations have been proliferating, leading to another, even greater problem. Jellyfish subsist by eating huge quantities of fish eggs and fry. If jellyfish populations are not kept in check by their natural predators they will help to undermine the base of oceanic ecosystems.
But the ultimate threat to life on earth, particularly leatherbacks and other nesting reptiles that bury their eggs in sand, is rapid climate change prompted by warming of the atmosphere and oceans—a fact recognized as early as 1953. In The Edge of the Sea, Rachel Carson explained the importance of a stable temperature to the oceans:
Life in the aggregate is lived within a relatively narrow range of temperature. The fact that our planet Earth has a fairly stable temperature helps make it hospitable to life. In the sea, especially, temperature changes are gradual and moderate and many animals are so delicately adjusted that they cannot tolerate an abrupt or extensive change in temperature of the surrounding water. If such occurs they must migrate or die…. Now our climate is changing and we are moving into a warm cycle of unknown duration.19
Turtles lack sex chromosomes. Their genes do not directly determine whether a baby turtle is male or female. Instead, buried eggs take their gender cue from the ambient temperature of the sand. For leatherbacks, temperatures below 85°F (29.4°C) produce a clutch that is mostly male; above that, it’s mostly female. With a relatively tiny 3.6°F (2°C) increase, a nest will produce all females, which is already beginning to happen.20 A few degrees higher yet, and the “boiled” eggs don’t hatch at all.
Unless we do something about limiting climate change to less than 2°C, these majestic creatures, from a species that is 100 million years old, will be driven to extinction because they will only produce females.
Warmer Oceans
The world’s oceans are absorbing an estimated 90 percent of the excess heat generated by global warming.21 The effects of the increasing water temperatures go way beyond affecting leatherback turtles. As Rachel Carson noted, species are forced to migrate to colder waters, displacing those already there. Greater rates of evaporation put more water vapor into a warmer atmosphere that can hold more water, thus leading to more severe downpours and extreme rainfall events.
Temperatures are increasing in the Arctic and Antarctic at greater rates than in the middle latitudes. As a result, over the last fifty years, Arctic Ocean ice has vanished from an area twice the size of Alaska and the remaining ice is 50 percent thinner. The lowest maximum winter ice in thirty-seven years of satellite data occurred in February and March of 2016. The year 2016 tied with 2007 for the second lowest Arctic summer sea-ice level on record; the lowest occurred in 2012.22 Later in the same year the situation became even more striking: “On October 20, 2016, Arctic sea ice extent began to set new daily record lows for this time of year.” When Arctic and Antarctic sea ice extents are combined for September through November 2016, the quantity is dramatically lower than for those months in any previous year on record.23
During the summer months ice reflects 50 percent of the sun’s rays, helping to cool and regulate planetary temperature. By contrast, open water absorbs 90 percent of incoming sunlight, warming the water even more. Warmer air temperatures play a major role in ice melt, as does the self-reinforcing impact of ice disappearing. In a classic example of a positive feedback loop, warming Arctic waters lead to more ice melt, which exposes more dark sea, which absorbs more heat, which melts more ice, and so on. It should come as little surprise that the loss of sea ice appears to be accelerating.
More and more evidence indicates that decreasing Arctic Ocean sea ice is altering the jet stream and already affecting weather patterns around the world.24
The accelerated melting of the gigantic Greenland ice sheet is as dramatic as the disappearance of Arctic sea ice: over 50 percent of the surface was melting during the summer of 2015, contributing to the thirty-sixth consecutive year of global glacier loss.
In contrast to the melting of the massive Greenland ice sheet, the greatest danger for ice loss resulting from warming air and oceans in the Antarctic is the flow of the continental glaciers into the sea. As they reach the sea, “ice shelves” in contact with the water are formed, with the shelves still attached to the ice sheet on land. Melting from below and under tidal forces, these shelves produce the greatest amount of ice loss in Antarctica. As the ice shelves melt and icebergs calve off, more ice flows from the land into the sea. The loss of ice in this most active ice-loss region “shows signs of becoming ‘unstoppable.’ There’s enough water locked up in West Antarctica’s Amundsen Sea region alone to raise the global average sea level by four feet, and it’s the fastest-melting spot on the continent.”25
As a result of thermal expansion and melting glaciers and ice sheets, sea levels rose about seven inches during the twentieth century, causing saltwater intrusion to damage low-lying coastal agricultural soils in Bangladesh, the Mekong Delta in Vietnam, and other areas of the world. The sea level is projected to rise another 1 to 4 feet by 2100.26