Moron-posting a picture of a pristine body of water proves nothing about what is happening on the macro level. Hard to argue with someone who is both intellectually dishonest and scientifically illiterate.
Quote:The final point that needs to be made with respect to the question of why we are worried today if coral reefs of undergone big changes in the past is that of timescale. When coral reefs have experience calamities in the past, they have been absent for very long periods (i.e. millions of years). These timescales are well beyond those that make any sense with respect to humans and their dependence on the ecological services provided by coral reefs.
Putting it bluntly, it is irrelevant that reefs have bounced back in geological time when the timescale of importance for the people depend on coral reefs (such as our vibrant tourist industry here in Australia, or the millions of people around the world need them for their food) is on a month to year basis .
Quote:Idiot - Great Barrier Reef Still Not Dying, Whatever Washington Post Says…
Quote:The decline of the Great Barrier Reef
What the science says...
The evidence clearly shows that ocean warming and acidification due to human CO2 emissions are adversely impacting the Great Barrier Reef.
Climate Myth...
Great Barrier Reef is in good shape
the Great Barrier Reef is in fine fettle (Bob Carter)
https://skepticalscience.com/great-barrier-reef-decline.htm
Is climate change a big threat to the Great Barrier Reef and how do we know?
Coral reefs like the Great Barrier Reef depend on a narrow set of environmental conditions within which they prosper. At the heart of their biology, is a symbiosis that they form with tiny plant-like organisms known as dinoflagellates (commonly called zooxanthellae). This symbiosis is critical to the survival of corals and coral reefs, making possible the efficient trapping of sunlight by reef-building corals. This allows them a cheap source of energy with which to grow in the sunlit waters along tropical coastlines, and where they often deposit of vast quantities of calcium carbonate (a limestone-like substance), creating the three-dimensional structures that we know of as coral reefs. These magnificent structures build up over time, attracting over one million species which are known to live in and around coral reefs (Reaka-Kudla 1997). This mega-diversity is unrivalled anywhere else in the ocean, and supports industries like tourism and fisheries, and provides food for at least 100 million people worldwide (Hoegh-Guldberg 1999).
Coral reefs have come under increasing pressure from the local effects discussed in Part 1 which arise from the rapidly growing coastal populations worldwide. In the early 1980s, coral reefs all over the world began to exhibit a phenomenon known as mass coral bleaching. Mass coral bleaching occurs when the symbiosis between corals and tiny plant-like organisms known as dinoflagellates breaks down. As a result, corals are deprived of their energy source, leaving them prone to disease and death. Over the past 25 years, mass coral bleaching and mortality events have grown in frequency and scale.
Corals survived in past climates with warmer temps and higher CO2 than now, so shouldn't GBR survive now?
The Great Barrier Reef has undergone major transformations in the geological past. During the glacial periods when large amounts of water have been locked up in glaciers and landlocked ice masses, sea levels were over 100 m lower than they are today. This meant that the Great Barrier Reef lagoon was completely exposed and was a wooded grassland not too dissimilar to those found in Queensland today. All of the islands and reef structures that remained after the water retreated were covered with soil and were unrecognisable as coral reefs.
This has prompted some to ask: Why are we so worried about climate change today if the Great Barrier Reef has undergone these types of changes in the past?
The answer to this question is straightforward and comes down to the issue of the rate of change. The changes in temperature and sea level associated with glacial cycles occurred over 10-20,000 years. In this period of time, global temperatures changed by 5-8 degrees Celsius and atmospheric concentrations of carbon dioxide by 100 ppm.
If we compare these sets of changes to that going on today, we see that we are undergoing similar set of changes only we are undertaking them in less than 100 years. That essentially means that the rate of change today is about 100-200 times faster than in the past.
