Claim: Ocean acidification causing coral ‘osteoporosis’ on iconic reefs

by WOODS HOLE OCEANOGRAPHIC INSTITUTION, August, 28, 2020 in WUWT


Scientists have long suspected that ocean acidification is affecting corals’ ability to build their skeletons, but it has been challenging to isolate its effect from that of simultaneous warming ocean temperatures, which also influence coral growth. New research from the Woods Hole Oceanographic Institution (WHOI) reveals the distinct impact that ocean acidification is having on coral growth on some of the world’s iconic reefs.

 

IMAGE: WHOI SCIENTIST ANNE COHEN (LEFT) AND MIT-WHOI JOINT PROGRAM STUDENT NATHAN MOLLICA EXTRACT CORE SAMPLES FROM A GIANT PORITES CORAL IN RISONG BAY, PALAU. view more CREDIT: PHOTO BY RICHARD BROOKS, LIGHTNING STRIKE MEDIA PRODUCTIONS, PALAU.

In a paper published Aug. 27, 2020, in the journal Geophysical Research Letters, researchers show a significant reduction in the density of coral skeleton along much of the Great Barrier Reef–the world’s largest coral reef system–and also on two reefs in the South China Sea, which they attribute largely to the increasing acidity of the waters surrounding these reefs since 1950.

“This is the first unambiguous detection and attribution of ocean acidification’s impact on coral growth,” says lead author and WHOI scientist Weifu Guo. “Our study presents strong evidence that 20th century ocean acidification, exacerbated by reef biogeochemical processes, had measurable effects on the growth of a keystone reef-building coral species across the Great Barrier Reef and in the South China Sea. These effects will likely accelerate as ocean acidification progresses over the next several decades.”

Roughly a third of global carbon dioxide emissions are absorbed by the ocean, causing an average 0.1 unit decline in seawater pH since the pre-industrial era. This phenomenon, known as ocean acidification, has led to a 20 percent decrease in the concentration of carbonate ions in seawater. Animals that rely on calcium carbonate to create their skeletons, such as corals, are at risk as ocean pH continues to decline. Ocean acidification targets the density of the skeleton, silently whittling away at the coral’s strength, much like osteoporosis weakens bones in humans.

New confirmation that climate models overstate atmospheric warming

by Dr. Judith Curry, August 27, 2020 in WUWT


Reposted from Dr. Judith Curry’s Climate Etc.

Posted on August 25, 2020

by Ross McKitrick

Two new peer-reviewed papers from independent teams confirm that climate models overstate atmospheric warming and the problem has gotten worse over time, not better.

The papers are Mitchell et al. (2020) “The vertical profile of recent tropical temperature trends: Persistent model biases in the context of internal variability” Environmental Research Letters, and McKitrick and Christy (2020) “Pervasive warming bias in CMIP6 tropospheric layers” Earth and Space Science. John and I didn’t know about the Mitchell team’s work until after their paper came out, and they likewise didn’t know about ours.

Mitchell et al. look at the surface, troposphere and stratosphere over the tropics (20N to 20S). John and I look at the tropical and global lower- and mid- troposphere. Both papers test large samples of the latest generation (“Coupled Model Intercomparison Project version 6” or CMIP6) climate models, i.e. the ones being used for the next IPCC report, and compare model outputs to post-1979 observations. John and I were able to examine 38 models while Mitchell et al. looked at 48 models. The sheer number makes one wonder why so many are needed, if the science is settled. Both papers looked at “hindcasts,” which are reconstructions of recent historical temperatures in response to observed greenhouse gas emissions and other changes (e.g. aerosols and solar forcing). Across the two papers it emerges that the models overshoot historical warming from the near-surface through the upper troposphere, in the tropics and globally.

Mitchell et al. 2020

Mitchell et al. had, in an earlier study, examined whether the problem is that the models amplify surface warming too much as you go up in altitude, or whether they get the vertical amplification right but start with too much surface warming. The short answer is both.

No Fuel, No Fire

by Mike Jonas, August 25, 2020 in WUWT


With wildfires devastating California, it may be worth while seeing if lessons can be learned from Australia. Connections between American and Australian firefighters go back many years, with each helping the other from time to time. There were devastating bushfires in Australia last summer, and, tragically, three Americans who had come to help were killed when their water tanker plane crashed. It’s now Australia’s turn to help California, and let us all hope there is a better outcome.

Gum trees burnt in the bushfires in The Blue Mountains in Australia

Submissions to Enquiries

Australia’s federal enquiry into the bushfires is not due to report until 28 October 2020 but the NSW [New South Wales] state enquiry report was published today. There were nearly 2,000 public submissions. Before I go into the report’s recommendations, it may be worth looking at a couple of the public submissions in order to understand the extreme level of public frustration with green tape and the way that the fire hazard has been allowed to grow ever larger over the years.

Astrophysicist Asserts The Globe Will Cool ~1°C During 2020-2053 Due To An Oncoming Grand Solar Minimum

by K. Richard, August 27, 2020 in NoTricksZone


During the last Grand Solar Minimum (17th century), global surface temperatures dipped to the coldest of the last 10,000 years – about 1.4°C colder than today. Dr. Zharkova, an astrophysicist, has determined another imminent drop in solar activity will lead to a 1°C cooling in the coming decades.

From 1645 to 1710, the Sun went into a quiet phase referred to as the Maunder Minimum. During this period, the “surface temperature of the Earth was reduced all over the Globe” (Zharkova, 2020). Cold summers and winters ensued, with glaciers extending onto farmland, sea ice expanding beyond the Arctic, and “frost fairs” on frozen rivers in Europe.
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The coldest temperatures and most expansive ice extent (glaciers,  permafrost, sea ice) of the last 10,000 years occurred during both this period and the surrounding centuries – often referred to as the Little Ice Age (LIA) (Glazer et al., 2020Geirsdottir et al., 2019).

In a new paper, Dr. Valentina Zharkova asserts that during solar cycles 25-27, the Sun may return to a modern Maunder-like Grand Solar Minimum. This solar quiet phase is expected to substantially reduce the Earth’s solar magnetic field, which will, in turn, lead to an increase in cosmic rays extending into Earth’s atmosphere and thus an increase in high clouds reflecting the Sun’s radiation back to space.

The consequence? A reduction in global temperatures to just 0.4°C above what they were in 1710.

The role of atmospheric CO2 as a temperature-driving mechanism is not mentioned in the paper.