The Impact Of Climate Change On The Biggest Coral Reef

Nestled at a mere 1,500 miles long, the Great Barrier Reef off the coast of Australia is home to approximately 9,000 species of marine life — when you visualize it, the Reef’s magnificence and dazing beauty is the first thing that comes to mind. However, majesty does not indicate immortality. Recently, the Great Barrier Reef endured two drastic bleaching events that occurred over the span of two years (starting with the 2016 bleaching, where roughly a fifth of the corals perished). Not only has the vast and swift die-off of the corals caused widespread concern among scientists over the Reef’s future vitality, it has prompted even larger distress in how such happenings — if they persist at similar scales — will completely alter the character of the coral community and ecosystem in its entirety. In no form, though, do these incidences emerge at the mystification of the offenders that precede them. Rampant, human-induced climate change is the single greatest threat posed against the long-term wellbeing of the Great Barrier Reef. Scientists around the world are in consensus of the extent that the incurred damage on the coral reef system alludes to rising sea temperatures, ocean acidification, and increased frequency of severe weather events as a result of global warming. The continued survival of coral reefs in oceans around the world (including the Great Barrier Reef) depend heavily on the action that must be taken to diminish greenhouse gas emission levels over the coming years and decades. The main question: what drivers of pollution are most imperative for us to fixate our attention to?

In consideration of timescales that vary from hundreds to hundreds of thousands of years, climate change has often befallen on earth due to natural causes. Yet, in scope of more contemporary timescales (commencing from the Industrial Era), with the basis of substantial evidence, it is clear that the environmental changes that have occurred over the last few decades are in strong correlation to human activity. These ecological shifts in part of human influences derive from the combustion of fossil fuels (or hydrocarbon fuels) that, consequently, modify the earth’s radiative equilibrium by altering the composition of its atmosphere; in effect, this enhances the natural greenhouse effects and augments the reflectivity of the earth’s surface and atmosphere. At a global scale, the primary factors in human-induced greenhouse gases are Carbon dioxide (CO2), Methane (CH4), Nitrous oxide (N20), and Fluorinated gases (F-gases). These greenhouse gas emissions can also be supplemented by the economic activities/sectors that largely lead to their production: Electricity and Heat Production (such as burning of coal, natural gas, and oil for heat and electricity); Industry (fossil fuels burned on site at facilities for energy); Agriculture & Forestry (cultivation of crop and livestock in addition to deforestation); Transportation (petroleum-based fuels, mainly gasoline and diesel, burned for road, rail, air, and marine transportation).

You may be thinking, how does any of this affect the ocean so greatly when the effects aren’t immediately apparent? The answer to this is simple: you don’t…not yet. Decades of research show that there is strong evidence in support of ocean’s critical role in regulating these gases as a buffer against the damage of climate change. Particularly, over 90% of the heat that is received from these gases are being trapped in the atmosphere and are directly absorbed by the ocean. Without the ocean as a buffer, the average global temperature would be resting around 120 degrees (Fahrenheit), far beyond the suit of habitable conditions for almost any earthly species. As the level of carbon emissions increase in our atmosphere, so do the number of stressors that pose an accumulating strain on the ocean’s defense. Among the more potent dangers of a warming atmosphere are warming sea temperatures and ocean acidification. Given that coral reefs are especially sensitive to increases in temperature, research shows that these extended, severe oceanic “heat waves” will push more marine animals and ecosystems to their dire limits in domino order. The ocean absorbs roughly a third of the carbon dioxide floating in the atmosphere, consisting of a mere 22 million tons every day. Accordingly, ocean acidification is about 30 times larger than traditional variations, resulting in a drop of the ocean’s average pH level by 0. 1 unit — that’s relative to a 25% rise in acidity, which is fairly significant to say the least. From the time of the Industrial Revolution, the ocean has faced a 30% increase in acidity in addition to a 35% rise in atmospheric CO2 as a result from burned fossil fuels. This increase in acidity infringes marine species’ ability to utilize calcium carbonate to shape their skeletons and shells. However, on a macro scale, this impacts entire marine ecosystems as coral reefs, which greatly rely on calcium carbonate to form their reef structures, in turn reside as homes for many reef organisms. Since the ocean is a crucial climate regulator, acidification will decrease the outflow of the sea’s sulfur into the atmosphere, reducing solar radiative reflection, thereby creating a loop of positive feedback exponentiating atmospheric CO2.

The Great Barrier Reef stands symbolically as a key ecological, social, cultural, and economic asset at risk under climate change as well as a posed warning sign for coral reefs around the world. However, the Great Barrier Reef will not be able to withstand as a symbol for anything as long as the drivers of climate change continue their path. Mining, for example, has expanded exponentially in the region covering the last 10 years, with it carrying a stimulation of shipping and ports conduction. It has been estimated that roughly 21 million cubic meters of dredge spoil from ports was dumped in the ocean in shy proximity to the Great Barrier Reef World Heritage Area covering the years of 2000 and 2013. Although, luckily, considerable measures have been taken by the Australian government to manage the impact incurred on the Reef. Legislation drafted by the government in 2015 mandated a ban on dumping of dredge spoil in the Great Barrier Reef Area as well as a prohibition of major capital dredging outside four primary ports. Yet, despite these actions, approximately 1 million tons of maintenance spoil per annum continue to be dumped with suitable ecological approvals. Additionally, the amount and frequency of visiting vessels is expected to surge by 250% extending through the year 2020. The interactions between the Reef, climate, and other stressors are expected to yield detrimental synergies. In illustration, corals exposed to the previously noted dredge spoil, including other pollutants and sedimentation, are vulnerable to bleaching and disease. Continually, stressors that cause further impediment result from the poor water quality as a result of these spoils, making the recovery potential of reef communities much bleaker.

Resilient and well-funded institutions will be greatly needed to ensure the fortitude of the coral reefs against these stresses. There is, though, current debate in regard to the vivacity of current legislation and regulation to sufficiently protect the coral and bolster the Reef’s strength to weather current and future stresses. Independent risk assessment and management ploys could provide a groundwork for evidence-based, financed adaptation strategies (like agricultural buy-back, regulatory reform to impede further polluting and land clearance). The Queensland Government established the Great Barrier Reef Water Science Taskforce in 2015, providing intelligence on how to achieve improved water quality targets. Subsequently, in 2016, Queensland purchased rehabilitative property disclosed for relieving roughly half the sediment runoff of the northern Reef.

With the resources we have today, it is important to understand the necessity of protecting the way ocean ecosystems naturally facilitate CO2 as well as governing the global carbon cycle, all vital steps to ensuring earth’s capability for sustaining life. To promote ecological conservation, we must restore the ocean and coastal areas that amass stored carbon using a science-based, data-driven approach. This should detail the reduction of human-initiated stresses on marine bionetworks by instituting thorough accounting and transparent administrations to safeguard these solutions without providing loopholes to subordinate ambitions. Collectively, we must be able to work with partners to identify organizational changes that will support commercial, recreational, and other uses of ocean resources while continuing toward a sustainable future. Recognizing and protecting our ocean’s role in the climate structure is central to guaranteeing a healthy future for our ocean as well as being unified and ready to combat whatever comes next.