Friday, June 04, 2021

Koonin responds to a Scientific American article by Oreskes et al.

On 2nd., I put up a short demolition of the Oreskes et al attack on the work of Steven Koonin. Koonin's own rebuttal has now come to hand so I reproduce it below

Scientific American has published a criticism of me and my recent book, Unsettled. Most of that article’s 1,000 words are scurrilous ad hominem and guilt-by-association aspersions from the twelve co-authors. Only three scientific criticisms are buried within their spluttering; here is my response to each them.

The first criticism concerns rising temperatures: A recent Washington Post column by conservative contributor Marc Thiessen repeats several points Koonin makes. The first is citing the 2017 National Climate Assessment to downplay rising temperatures—but the report’s very first key finding on the topic says temperatures have risen, rapidly since 1979, and are the warmest in 1,500 years.

In fact, Unsettled explicitly acknowledges a warming globe, but also the problems in comparing instrumental and proxy temperatures that weaken confidence in the “warmest in 1,500 years”.

The book’s Chapter 5 criticizes in detail the 2017 report’s misleading and inaccurate representation of a different temperature metric, US extreme temperatures. To the surprise of many, the country’s warmest temperatures have not increased since 1960 and are no higher in recent years than they were in 1900.

The authors go on to offer: The second is Thiessen quoting Koonin’s use of an outdated 2014 assessment on hurricanes to downplay climate concerns. But the newer 2017 report finds that human activity has “contributed to the observed upward trend in North Atlantic hurricane activity since the 1970s.”

In fact, Unsettled’s Chapter 6 discusses the description of hurricanes in the 2014 report, in the 2017 report, and in more recent research papers through 2020, including an authoritative 2019 assessment by eleven hurricane experts. None of those studies claim any detectable human influences on hurricanes.

Finally, we’re given: A third point downplays sea level rise by portraying it as steady over time, cherry-picking reports from the Intergovernmental Panel on Climate Change. In fact, the rate of sea-level rise has quadrupled since the industrial revolution, as climate scientists pointed out years ago when Koonin made this same argument.

In no sense does Unsettled portray sea level rise as “steady over time”. Rather, the book’s Chapter 8 does quite the opposite, describing the full decadal variability as portrayed in the IPCC reports and subsequent research literature, but somehow omitted in the 2017 National Climate Assessment. The IPCC statement that rates of rise between 1920 and 1950 were likely similar to those of recent decades complicates attribution of recent trends.

It is telling that these three criticisms cite Thiessen’s column rather than what I’ve written in Unsettled. That they are readily countered suggests the authors haven’t read the book or, if they have, they aren’t acting in good faith. That’s precisely the same unprofessional behavior found in the easily rebutted “fact check” of, again, a review of Unsettled, not the book itself.

To paraphrase a statement attributed to Einstein, “If I were wrong, it wouldn’t take a dozen scientists to disprove me - one would be sufficient.”

As I write in Unsettled, I welcome serious, informed discussion of any of the points I raise in the book. Unfortunately, the article by Oreskes et al. falls well short of that standard.

Steven E. Koonin is the author of the bestselling book Unsettled: What climate science tells us, what it doesn’t, and why it matters.


Warming effect of greenhouse gases 'has been overestimated': Ice samples suggest pre-industrial air pollution was WORSE than we thought

Which demolishes all previous Greenie statistics on the subject

Antarctic ice has revealed that pre-industrial air pollution was worse than thought, suggesting climate models have overstated the warming from greenhouse gases.

Key to modelling the climate of the future is understanding how the rate at which surface temperatures are likely to rise in response to greenhouse gas levels.

To do this, modern climate models start by looking at how temperatures responded to known changes in the past — and then extrapolating from there.

The problem is that while past greenhouse gas levels are well documented, they are not the only things in the atmosphere that can affect surface temperatures.

Aerosols, as released by volcanoes and fires, have a cooling effect — but, unlike greenhouse gases, their levels before the Industrial era are poorly understood.

A team led from Harvard University analysed cores of Antarctic ice, trapped in which were soot particles from Africa, Australia and South America dating back to 1750.

Analysing this suggested that — in the southern hemisphere at least — pre-industrial times were more fiery than was previously anticipated, with four times the soot.

This means that, before 1780, the atmosphere was being cooled by soot more than expected — with implications for atmospheric models based on this assumption.

Specifically, in order to account for the observed increase in surface temperatures since then, models may have overestimated the warming from greenhouse gases.

While the world is 'clearly' warming, as the team put it, the new findings suggest that it might not be heating up at quite the rate that was previously feared.

'Up till now, the magnitude of past fire activity, and thus the amount of smoke in the preindustrial atmosphere, has not been well characterized,' explained paper author and atmospheric chemist Pengfei Liu of Massachussets' Harvard University.

'These results have importance for understanding the evolution of climate change from the 1750s until today, and for predicting future climate.'

In total, Dr Liu and colleagues analysed the content of 14 different ice cores, each bored up from a different location across the southernmost continent.

'Soot deposited in glacier ice directly reflects past atmospheric concentrations so well-dated ice cores provide the most reliable long-term records,' explained hydrologist Joseph McConnell of the Desert Research Institute in Nevada.

The researchers were surprised to find that the pre-industrial (here defined as 1750–1780) soot levels were considerably higher than was long thought.

'While most studies have assumed less fire took place in the preindustrial era, the ice cores suggested a much fierier past, at least in the Southern Hemisphere,' said atmospheric chemist Loretta Mickley, also of Harvard University.

To account for these surprising levels of soot, the team ran computer simulations which explored both the impact of wildfires and the burning practices of indigenous peoples in the southern hemisphere.

'The computer simulations of fire show that the atmosphere of the Southern Hemisphere could have been very smoky in the century before the Industrial Revolution,' said earth scientist Jed Kaplan of the University of Hong Kong.

'Soot concentrations in the atmosphere were up to four times greater than previous studies suggested,' he added.

'Most of this was caused by widespread and regular burning practiced by indigenous peoples in the pre-colonial period.'

Indeed the smelting of copper is known to have taken place in South America from as early as 1400 BC, with the Incas smelting silver ore later that century and air pollution increasing when the conquistadors invaded the century after.

Both the ice core data and the models conclude that soot levels were abundant before the industrial era and remained relatively constant across the 20th century.

As land use changed — and fire activity decreased — emissions from industry increased instead, the models suggest.

'Climate scientists have known that the most recent generation of climate models have been over-estimating surface temperature sensitivity to greenhouse gasses, but we haven't known why or by how much,' explained Dr Liu.

'This research offers a possible explanation', he noted. The new finding, added Dr Mickley, 'allows us to refine our predictions moving forward.'

'Clearly the world is warming but the key question is how fast will it warm as greenhouse gas emissions continue to rise, she added.

The full findings of the study were published in the journal Science Advances.


Climate change blamed for more than a third of heat-related deaths

Will this nonsense ever stop? For a start: It' arguable that ANY deaths occur in response to heat. I grew up in the topics where we have "heatwaves" for most of sunmmer. But where were the epidemics of deaths from it? We saw none. We had electric fans, cold beer and places to go swimming. So we coped. The weather problems described below stemmed from a failure to adapt to the climate

And the big season of dying is winter. Cold kills, not warmth. Warmth undoubtedly saves lives

Human-caused global warming was responsible for thousands of heat-related deaths in recent decades, a fraction of the numbers expected in the future even if nations adopt ambitious emissions-cutting efforts.

Research of 30 million deaths, spanning almost three decades in 732 locations in 42 countries, found 37 per cent of heat-related mortality could be attributed to climate change. For Brisbane, Melbourne and Sydney, there were almost 3000 extra deaths, the international study, published on Tuesday in Nature Climate Change journal, found.

The authors, including two based at Australian universities, applied the latest epidemiological and climate models to assess warm-season changes. The result was the largest such study of the health impacts of a hotter world to date, they said.

“We have demonstrated that health burdens from anthropogenic climate change are occurring, are geographically widespread and are non-trivial,” the paper concluded. “In many locations, the attributable mortality is already in the order of dozens to hundreds of deaths each year.”

Yuming Guo, head of Monash University’s Climate, air quality research unit, said warm-season heat-related deaths in Australia amounted to about 1.8 per cent of the total, of which about one-third can be attributed to climate change. That ratio is in line with the rest of the world, he said.

“Australians are still sensitive to heat, particularly extreme heat,” Professor Guo said. Even though residents could expect to access more air-conditioning and other relief from high temperatures, an ageing population brought extra deaths in line with other parts of the world.

For the 1991-2018 period, there were 2968 deaths in the three Australian cities that could be attributed to climate change, Professor Guo told the Herald and The Age. Sydney had the highest toll at 1484, with Melbourne at 924 and Brisbane suffering 560 extra deaths.

The fatalities would likely be proportionally higher in other parts of the country. “Normally low socio-economic areas have a higher mortality,” Professor Guo said.

Still, the additional deaths are occurring when average global temperatures have only increased about 1 degree since 1900. “That rise is lower than even the strictest climate targets outlined in the Paris Agreement [to limit warming to 1.5–2 degrees] and a fraction of what may occur if emissions are left unchecked”, the researchers said


Climate crisis is suffocating the world’s lakes, study finds

Most likely it is increased use of river water by humans that explains any effect here. Taking more from the rivers reduces inflow to the lakes

The climate crisis is causing a widespread fall in oxygen levels in lakes across the world, suffocating wildlife and threatening drinking water supplies.

Falling levels of oxygen in oceans had already been identified, but new research shows that the decline in lakes has been between three and nine times faster in the past 40 years. Scientists found oxygen levels had fallen by 19% in deep waters and 5% at the surface.

Rising temperatures driven by global heating is the main cause, because warmer water cannot hold as much oxygen. Furthermore, rising summer heat leaves the top layer of lakes hotter and less dense than the waters below, meaning mixing is reduced and oxygen supply to the depths falls.

Oxygen levels have increased at the surface of some lakes. But this is most likely due to higher temperatures driving algal blooms, which can also produce dangerous toxins. Cutting emissions to tackle the climate crisis is vital, the scientists said, as well as cutting the use of farm fertiliser and urban sewage pollution that also damages lakes.

“All complex life depends on oxygen and so, when oxygen levels drop, you really decrease the habitat for many different species.” said Prof Kevin Rose, of the Rensselaer Polytechnic Institute (RPI) in the US, who was part of the research team.

“This study proves that the problem is even more severe in fresh waters [than in oceans], threatening our drinking water supplies and the delicate balance that enables complex freshwater ecosystems to thrive,” said Curt Breneman, RPI’s dean of science.

Freshwater habitats are rich in fish, insects, birds and animals, and are important for food and recreation for humans. But they have already suffered great damage, with average wildlife populations having fallen by 84% since 1970. In addition to global heating and pollution, the causes include overuse of water for farming.

The study, published in the journal Nature, analysed 45,000 dissolved oxygen and temperature profiles collected from nearly 400 lakes worldwide. Most records started in about 1980, though one went back to 1941.

Most of the lakes were in temperate zones, particularly in Europe and the US, but there were a few records from higher latitudes, nearer the poles, and for tropical lakes in Africa. In both cases, oxygen was falling as in the other lakes.

In lakes where oxygen levels have fallen to almost zero, phosphorus can be drawn out of sediments, providing an essential nutrient for bacteria. These can proliferate and produce the powerful greenhouse gas methane, driving further heating.

Oxygen levels in surface waters were increasing in about a fifth of the lakes studied, almost all of which were prone to pollution. This is an indicator of widespread increases in algal blooms, said Rose. “Without taxonomic data, we can’t say that definitively, but nothing else we’re aware of can explain this pattern.”

Global temperatures are still rising, pushing lake oxygen levels ever lower, so just keeping the status quo requires action to clean up freshwater bodies. Rose said a positive example was Oneida Lake in New York state, where a clean-up led to better water clarity, which in turn allowed more photosynthesis from oxygen-producing algae.

“The new study provides a much-needed global overview of what happens in the limited freshwater stores of the planet – their health is a prime concern,” said Prof Hans-Otto Poertner, of the Alfred-Wegener-Institute in Bremerhaven, Germany, who was not part of the team. Lakes are isolated and small compared with oceans, in which global currents can still provide oxygen to deeper waters, he said.

“Climate change, together with [agricultural pollution], threatens vulnerable freshwater systems, adding to the urgency to strongly cut emissions,” Poertner said.




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