Is happening.
Yes, AGW is happening and that can be shown by spectrometer readings—no models or theories needed.
See:
http://www.ozpolitic.com/forum/YaBB.pl?num=1464603948/1856#1856That settled, what problems is AGW causing?
Low global oceanic oxygen is one. We know the oceans are absorbing a lot of the CO2 we emit and this causes problems for organisms to create their calcium carbonate shells, especially by the plankton that is the base of the food pyramid in our seas—ocean acidification, which means our oceans are getting less alkaline and so more acid, not that our oceans are becoming acidic. Mention that because people get that term wrong.
Lack of global oxygen is another.
Quote:A large research synthesis, published in one of the world’s most influential scientific journals, has detected a decline in the amount of dissolved oxygen in oceans around the world — a long-predicted result of climate change that could have severe consequences for marine organisms if it continues.
The paper, published Wednesday in the journal Nature by oceanographer Sunke Schmidtko and two colleagues from the GEOMAR Helmholtz Centre for Ocean Research in Kiel, Germany, found a decline of more than 2 percent in ocean oxygen content worldwide between 1960 and 2010. The loss, however, showed up in some ocean basins more than others. The largest overall volume of oxygen was lost in the largest ocean — the Pacific — but as a percentage, the decline was sharpest in the Arctic Ocean, a region facing Earth’s most stark climate change.
https://www.washingtonpost.com/news/energy-environment/wp/2017/02/15/its-officia...If you think it odd that the ocean can absorb more CO2 but lose oxygen content then remember that there is a lot more O2 than CO2 in our seas: 18% oxygen v .04% CO2 in the atmosphere
Quote:Ocean oxygen is vital to marine organisms, but also very delicate — unlike in the atmosphere, where gases mix together thoroughly, in the ocean that is far harder to accomplish, Schmidtko explained. Moreover, he added, just 1 percent of all the Earth’s available oxygen mixes into the ocean; the vast majority remains in the air.
So any loss of oxygen will be hard to replace. And the loss of oxygen is not evenly spread in depth:
Quote:“When the upper ocean warms, less water gets down deep, and so therefore, the oxygen supply to the deep ocean is shut down or significantly reduced,” Schmidtko said.
Oxygen enters the sea directly from the atmosphere and by photosynthesis by ocean plants and algae, including the algae living symbiotically with coral.
Quote:The new study represents a synthesis of literally “millions” of separate ocean measurements over time, according to GEOMAR. The authors then used interpolation techniques for areas of the ocean where they lacked measurements.
The resulting study attributes less than 15 percent of the total oxygen loss to sheer warmer temperatures, which create less solubility. The rest was attributed to other factors, such as a lack of mixing.
Quote:“Natural variations have obscured our ability to definitively detect this signal in observations,” Long said in an email. “In this study, however, Schmidtko et al. synthesize all available observations to show a global-scale decline in oxygen that conforms to the patterns we expect from human-driven climate warming. They do not make a definitive attribution statement, but the data are consistent with and strongly suggestive of human-driven warming as a root cause of the oxygen decline.
“It is alarming to see this signal begin to emerge clearly in the observational data,” he added.
“Schmidtko and colleagues’ findings should ring yet more alarm bells about the consequences of global warming,” added Denis Gilbert, a researcher with the Maurice Lamontagne Institute at Fisheries and Oceans Canada in Quebec, in an accompanying commentary on the study also published in Nature.
It gets worse:
Quote:Because oxygen in the global ocean is not evenly distributed, the 2 percent overall decline means there is a much larger decline in some areas of the ocean than others.
Moreover, the ocean already contains so-called oxygen minimum zones, generally found in the middle depths. The great fear is that their expansion upward, into habitats where fish and other organism thrive, will reduce the available habitat for marine organisms.
In shallower waters, meanwhile, the development of ocean “hypoxic” areas, or so-called “dead zones,” may also be influenced in part by declining oxygen content overall.
On top of all of that, declining ocean oxygen can also worsen global warming in a feedback loop. In or near low oxygen areas of the oceans, microorganisms tend to produce nitrous oxide, a greenhouse gas, Gilbert writes. Thus the new study “implies that production rates and efflux to the atmosphere of nitrous oxide … will probably have increased.”
Positive feedback loops are going to see a jump in atmospheric methane and CO2 and now we see nitrous oxide, a minor greenhouse gas in the atmosphere, is also increasing in the atmosphere. Not good.
cont’d