A Journal of People report
Interdecadal Pacific Oscillation (IPO) is likely to accelerate global warming, which may smash the agreed Paris target of 1.5°C by as early as 2026, finds a new research. And, the amount of dissolved oxygen contained in the water has been declining for more than 20 years, reveals another new research.
A research report from the University of New South Wales says:
Global temperatures could break through the 1.5°C barrier negotiated at the Paris conference as early as 2026 if a slow-moving, natural climate driver known as the Interdecadal Pacific Oscillation (IPO) has, as suspected, moved into a positive phase. (University of New South Wales. “Paris 1.5°C target may be smashed by 2026: A change to a positive phase of the Interdecadal Pacific Oscillation could see global warming accelerate rapidly.” ScienceDaily. ScienceDaily, 8 May 2017. http://www.sciencedaily.com/releases/2017/05/170508184929.htm>.)
The new research published in Geophysical Research Letters by the University of Melbourne scientists at the ARC Centre of Excellence for Climate System Science shows that a positive IPO would likely produce a sharp acceleration in global warming over the next decade. (Benjamin J. Henley, Andrew D. King. Trajectories toward the 1.5°C Paris target: Modulation by the Interdecadal Pacific Oscillation. Geophysical Research Letters, 2017; DOI: 10.1002/2017GL073480)
The May 8, 2017 datelined and “Paris 1.5°C target may be smashed by 2026” headlined Science Daily report said:
“Since 1999, the IPO has been in a negative phase but consecutive record-breaking warm years in 2014, 2015 and 2016 have led climate researchers to suggest this may have changed. In the past, these positive phases have coincided with accelerated global warming.”
“The IPO has a profound impact on our climate because it is a powerful natural climate lever with a lot of momentum that changes very slowly over periods of 10-30 years.
“During its positive phase the ocean temperatures in the tropical Pacific are unusually warm and those outside this region to the north and south are often unusually cool. When the IPO enters a negative phase, this situation is reversed.
“In the past, we have seen positive IPOs from 1925-1946 and again from 1977-1998. These were both periods that saw rapid increases in global average temperatures. The world experienced the reverse — a prolonged negative phase — from 1947-1976, when global temperatures stalled.
“A striking characteristic of the most recent 21st Century negative phase of the IPO is that on this occasion global average surface temperatures continued to rise, just at a slower rate.”
Dr Ben Henley, the lead author, according to the report, said:
“Even if the IPO remains in a negative phase, our research shows we will still likely see global temperatures break through the 1.5°C guardrail by 2031.”
Dr Ben Henley said:
“If the world is to have any hope of meeting the Paris target, governments will need to pursue policies that not only reduce emissions but remove carbon from the atmosphere.”
“Should we overshoot the 1.5°C limit, we must still aim to bring global temperatures back down and stabilize them at that level or lower.”
“Although the Earth has continued to warm during the temporary slowdown since around 2000, the reduced rate of warming in that period may have lulled us into a false sense of security. The positive phase of the IPO will likely correct this slowdown. If so, we can expect an acceleration in global warming in the coming decades,” Dr Henley said.
The scientist said:
“Policy makers should be aware of just how quickly we are approaching 1.5°C. The task of reducing emissions is very urgent indeed.”
Troubling oxygen decline in oceans
A new analysis of decades of data on oceans across the globe has revealed that the amount of dissolved oxygen contained in the water – an important measure of ocean health – has been declining for more than 20 years.
A research report from the Georgia Institute of Technology said:
Researchers at Georgia Institute of Technology looked at a historic dataset of ocean information stretching back more than 50 years and searched for long term trends and patterns. They found that oxygen levels started dropping in the 1980s as ocean temperatures began to climb.
The study published April in Geophysical Research Letters (Takamitsu Ito, Shoshiro Minobe, Matthew C. Long, Curtis Deutsch. Upper Ocean O2 trends: 1958-2015. Geophysical Research Letters, 2017; DOI: 10.1002/2017GL073613), was sponsored by the National Science Foundation and the National Oceanic and Atmospheric Administration.
The team included researchers from the National Center for Atmospheric Research, the University of Washington-Seattle, and Hokkaido University, Japan.
A “Decades of data on world’s oceans reveal a troubling oxygen decline” headlined Science Daily report said:
“Falling oxygen levels in water have the potential to impact the habitat of marine organisms worldwide and in recent years led to more frequent “hypoxic events” that killed or displaced populations of fish, crabs and many other organisms.” (Georgia Institute of Technology. “Decades of data on world’s oceans reveal a troubling oxygen decline.” ScienceDaily. ScienceDaily, 4 May 2017. <www.sciencedaily.com/releases/2017/05/170504104346.htm>.)
The May 4, 2017 datelined report said:
“Researchers have for years anticipated that rising water temperatures would affect the amount of oxygen in the oceans, since warmer water is capable of holding less dissolved gas than colder water. But the data showed that ocean oxygen was falling more rapidly than the corresponding rise in water temperature.”
“The majority of the oxygen in the ocean is absorbed from the atmosphere at the surface or created by photosynthesizing phytoplankton. Ocean currents then mix that more highly oxygenated water with subsurface water. But rising ocean water temperatures near the surface have made it more buoyant and harder for the warmer surface waters to mix downward with the cooler subsurface waters. Melting polar ice has added more freshwater to the ocean surface – another factor that hampers the natural mixing and leads to increased ocean stratification.
“In an earlier study, Ito and other researchers explored why oxygen depletion was more pronounced in tropical waters in the Pacific Ocean. They found that air pollution drifting from East Asia out over the world’s largest ocean contributed to oxygen levels falling in tropical waters thousands of miles away.
“Once ocean currents carried the iron and nitrogen pollution to the tropics, photosynthesizing phytoplankton went into overdrive consuming the excess nutrients. But rather than increasing oxygen, the net result of the chain reaction was the depletion oxygen in subsurface water.”
“The oxygen in oceans has dynamic properties, and its concentration can change with natural climate variability,” said Taka Ito, an associate professor in Georgia Tech’s School of Earth and Atmospheric Sciences who led the research. “The important aspect of our result is that the rate of global oxygen loss appears to be exceeding the level of nature’s random variability.”
“The trend of oxygen falling is about two to three times faster than what we predicted from the decrease of solubility associated with the ocean warming,” Ito said. “This is most likely due to the changes in ocean circulation and mixing associated with the heating of the near-surface waters and melting of polar ice.”
“After the mid-2000s, this trend became apparent, consistent and statistically significant — beyond the envelope of year-to-year fluctuations,” Ito said. “The trends are particularly strong in the tropics, eastern margins of each basin and the subpolar North Pacific.”
That, too, is likely a contributing factor in waters across the globe, Ito said.