One argument is that many different things are contributing to the destruction of coral rather than climate change including overfishing, marine pollution and cyclones/hurricanes (World Climate Report, 2010). Although this may be true, the main causes of coral reef destruction still relates back to global warming. From 1985 to 2012, coral populations in the Great Barrier Reef have decreased by 50.7 per cent, with 48 per cent due to tropical cyclones, 42 per cent because of crown of thorns starfish (COTS) and 10 per cent directly due to bleaching (De 'ath et al., 2012). It has been indicated that due to global warming, there has been an increase in the number of tropical cyclones (Knutson et al., 2010). However, it has also been found that there is a possibility of cyclones actually mitigating coral bleaching (Baker et al., 2008; Schultz, 2012).
Climate change is a long term change in the earth’s climate. Climate change is attributed largely to the increased levels of atmospheric carbon dioxide produced by the use of fossil fuels. There are 328,000,000 cubic miles of seawater on the planet, covering approximately 71 percent of the earth's surface. Ninety-seven percent of all water is in the oceans. The other three percent is divided amongst the two percent ice and one percent fresh water.
About 30% of CO2 emissions are taken up by the oceans today (Freely et al. 2004) and this percentage will continue to rise if nothing is done to prevent it, potentially leading to enhanced levels of ultraviolet radiation at the earth’s surface (Harley, C. D. G., et al, 2006). While many marine organisms have adapted to thermal fluctuations in the last few million years, the expected changes in pH are higher than any other pH changes inferred from the fossil record over the past 200–300 million years (Caldeira & Wickett 2003; Feelyet al. 2004). The following diagram represents the effect of greenhouse gas emissions on the oceans causing increased CO2, decreased pH, sea level rise, storm frequency and potential upwelling.
Introduction: Human activities have led to an exponential increase in the use of fossil fuel. The benefits of using fossil fuels are short lived in comparison to its long-term negative effects. In the last couple of decades, the major consumption of fossil fuel played a significant role in the rise of concentration of CO2 in the atmosphere. Roughly two trillion metric tons of CO2 have been emitted in the atmosphere and over a quarter of these got mixed with the ocean water resulting in ocean acidification (Buffie and Carr, 2010). Ocean acidification is the decrease of pH in the oceans due to absorption of CO2 in the atmosphere (Fabry, 2008).
He stated that marine life has endured large climatic changes and acidification discrepancies in the past but the anticipated rates of climate change and ocean acidification over the next century are much rapid than experienced by the planet earlier. The ocean has always absorbed CO2 from the air. An article presented in Nature August 2012 enlightens that about half of all CO2 generated by human is absorbed by the ocean. This chemical reaction is occurring naturally and the rate at which carbon is being absorbed, the concentration of carbonic acid is increasing. This has overwhelming concerns, particularly for shelled creatures.
Benefits and harms should be measured before making any conclusion. Anyhow, there is no doubt that carbon is mostly affecting the heat level of atmosphere. Human releasing emissions are root cause of this. Carbon is also causing acidification in oceans and less oxygen to the sea life. Till now climate changes has created many unfavorable and drastic events on earth so there should be a debate between the scientists of different views and solutions should be ruled out to reach the goal of making our environment healthy for centuries to come.
While it affects all environments, it has an extreme effect on coastal environments and estuarine environments since these environments rely heavily on chemical concentrations and pH balances. The pH balances have decreased majorly over the recent years since the industrial revolution because of increased partial pressure of carbon dioxide released into our environment and into the oceans. Because of this, ocean pH balance has now reached a record low for the past two million years. The high amount of carbon dioxide is increasing the levels of calcium carbonate, which is altering the performance of calcifiers and other marine organisms like the algal community. Lastly, the decreased pH balance in the seawater is causing high metal pollution, which also affects marine organisms(Ivanina & Sokolova, 2015).
Extinction of certain species is a real threat as past research has shown extinction rates dramatically increase as atmospheric carbon dioxide levels increase. Slower growing shells and skeletons can have an impact on the food webs of marine life, therefore threatening even well-established species. Important metabolic processes, such as respiration in fish, may also be impaired by the acidity, as lowering the pH reduces the efficiency of oxygen exchange in their gills. Many marine organisms also act as a carbon storehouse, so as the oceans continue to absorb more carbon dioxide these organisms are less likely to be able to do this effectively, increasing carbon dioxide levels in the atmosphere and ocean acidity further. The full effects of ocean acidification are not yet fully known but most scientists believe marine life will have trouble
Ocean acidification is one result of climate change. Acidification is caused by an increase of carbon dioxide in our oceans and leads to a decrease in the pH levels of seawaters. This pH decrease reduces the ability of corals to make their hard skeletons. Rates of coral calcification on the Great Barrier Reef and many other reef systems around the world have declined by 15-20% since 1990 due to increasing thermal stress (De’ath 2012). It has already been mentioned that the oceans are absorbing almost all of the excess heat from climate change.
According to Webster’s dictionary, “climate change is the change in global climate patterns apparent from the mid-to-late 20th century and onwards attributed largely to the increased levels of atmospheric carbon dioxide produced by the use of fossil fuel.” There is stronger evidence now than there has been in the past 50 years that climate change is actually a fact. As of today, carbon dioxide levels have risen higher than they had in the past fifty years. Ninety percent of this change can be blamed on humans. The estimated increase of carbon dioxide levels from the nineteenth century and now is 112 (112 what?? ), and quickly increasing (“The basics: A brief Introduction to Climate Change”).