Archive for the ‘modelling’ Category


The theme here is that aerosols have to some extent been having the opposite of the alleged effect of so-called greenhouse gases. This study, based on climate modelling, suggests at least some recent warming is linked to reductions in atmospheric aerosol content.
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A new NOAA study covering four decades of tropical cyclones found that reducing particulate air pollution in Europe and North America has contributed to an increase in the number of tropical cyclones in the North Atlantic basin and a decrease in the number of these storms in the Southern Hemisphere, says Green Car Congress.

The open-access study, published in Science Advances, also found that the growth of particulate pollution in Asia has contributed to fewer tropical cyclones in the western North Pacific basin.

While a number of recent studies have examined how increasing greenhouse gas emissions are impacting global tropical cyclone activity, Hiroyuki Murakami examined the less studied and highly complex area of how particulate pollution in combination with climate changes is affecting tropical cyclones in different areas of the planet.

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Are ‘corrections’ the answer? Avoiding the need for them might be better. The researchers observe that ‘the projected warming in response to greenhouse gases is too great’. This has been known for years but the penny of reliance on a certain climate theory has yet to drop, it seems.
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Climate projections are crucial for adaptation and mitigation planning says Eurekalert.

The output of the latest round of the Coupled Model Intercomparison Project, phase 6 (CMIP6) has been widely used in climate projections.

However, a subset of CMIP6 models is “too hot” and the projected warming in response to greenhouse gases is too great.

How to tackle the “hot model” problem at the regional scale had previously been unclear.

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Too much hot air


We’ve been hearing this for years, but here it is again. It seems hard to get climate science to follow best practice and discard models that perform poorly against observational data, or at least the worst ones. Time’s up now as it’s getting too embarrassing, with the climate clearly failing to comply with ultra-warmist predictions. But over-optimistic belief that the models are nearly on course is still rife.
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U.N. report authors say researchers should avoid suspect models – from Science.org.

One study suggests Arctic rainfall will become dominant in the 2060s, decades earlier than expected. Another claims air pollution from forest fires in the western United States could triple by 2100. A third says a mass ocean extinction could arrive in just a few centuries.

All three studies, published in the past year, rely on projections of the future produced by some of the world’s next-generation climate models.

But even the modelmakers acknowledge that many of these models have a glaring problem: predicting a future that gets too hot too fast.

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I’m delighted Ned Nikolov and Karl Zeller have chosen the Talkshop as the venue for the publication of this new open peer review paper on climate sensitivity. Scientific advance at the cutting edge has always been the most important aim of this blog, and I think this paper truly is an advance in our understanding of the climate system and the factors which support and modulate surface temperature on Earth and other rocky planets. 

The paper is mathematically rigorous, but is also accessible to everyone, thanks to Ned and Karl’s exemplary effort to fully explain their concepts and definitions in terms which can be understood by any interested reader who has some familiarity with the climate debate. Building on the bedrock of their 2014 and 2017 papers, this new work extends the applicability and validates the postulates of those previous papers by examining the causes of variability in planetary surface temperature and incorporating the previous findings in quantifying and deriving equations to model them. They find that Earth is sensitive to changes in cloud cover, which affects the amount of solar shortwave radiation reaching the surface, but not very sensitive to changes in Total Solar Irradiance arriving at the top of the atmosphere. They also find that the sensitivity to changes in CO2 levels has been heavily overestimated by current climate models. They show that a doubling of atmospheric CO2 concentration from 280 ppm to 560 ppm will cause an undetectable global warming of 0.004K.

A PDF of the paper can be downloaded here:  ECS_Universal_Equations.

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Exact Formulas for Estimating the Equilibrium Climate Sensitivity of Rocky Planets & Moons to Total Solar Irradiance, Absorbed Shortwave Radiation, Planetary Albedo and Surface Atmospheric Pressure.
Ned Nikolov, Ph.D. and Karl Zeller, Ph.D.
April, 2022

1. Introduction

The term “Equilibrium Climate Sensitivity” (ECS) has become a synonym for the steady-state response of global surface temperature to a modeled long-wave radiative forcing caused by a doubling of atmospheric CO2 concentration with respect to an assumed pre-industrial level of 280 ppm. According to climate models based on the Greenhouse theory, an increase of atmospheric CO2 from 280 ppm to 560 ppm would produce a net radiative forcing (i.e. an atmospheric radiant-heat trapping) of 3.74 W m-2 (Gregory et al. 2004) resulting in a global surface warming between 2.5 K and 4.0 K with a central estimate of 3.0 K according to IPCC AR6 (see p. 11 in Climate Change 2021: The Physical Science Basis. Summary for Policymakers). This implies an average unit ECS of 3.0/3.74 = 0.8 K / (W m-2) with a range of 0.67 ≤ ECS ≤ 1.07 K / (W m-2). Contemporary climate science and IPCC Assessment Reports do not discuss global temperature sensitivities to changes in cloud albedo, absorbed solar radiation or total surface atmospheric pressure. Consequently, no equations have been derived/proposed thus far to calculate these sensitivities. The reason for such an omission is the implicit assumption made by IPCC based on the 19th-Century Greenhouse theory (Arrhenius 1896) that the observed warming during most of the 20th Century and especially over the past 40 years was chiefly caused by an increase of industrial CO2 emissions, which are believed to trap outgoing long-wave radiation in the Earth’s troposphere and reduce the rate of surface infrared cooling to Space.

However, a plethora of studies published during the past 15 years have shown through both satellite and surface observations that the absorption of solar radiation by the Earth-atmosphere system has increased significantly since 1982 due to a decreased cloud cover/albedo, a phenomenon often referred to as “global brightening” (e.g. Goode & Pallé 2007; Wild 2009; Herman et al. 2013; Stanhill et al. 2014; Hofer et al. 2017; Pfeifroth et al. 2018; Pokrovsky 2019;  Delgado-Bonal et al. 2020; Dübal & Vahrenholt 2021;  Yuan et al. 2021). This implies a global warming driven by a rising surface solar radiation rather than CO2.

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That’s what it amounts to, even if the phrasing is different. Scenarios based on theories of climate that aren’t borne out by reality are the curse of modelling. All they seem to come up with is impossible demand reduction i.e. much less of everything – except renewables of course. It can’t get any better while their built-in CO2 obsession persists.
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Renewable energy transition won’t come fast enough to solve the climate crisis—we also need to reduce global energy consumption, according to new research from UNSW Sydney.

The research, published recently in Climate Policy, models different energy-use scenarios for reducing global energy-related CO2 emissions to zero by 2050, says Phys.org.

It found that simply substituting fossil fuels with renewable energy at current energy usage levels is no longer enough.

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Antarctic sea ice [image credit: BBC]


The obvious conclusion would be that the climate models are wrong, due to application of incorrect climate theory. As usual, researchers cast around desperately for other alternatives, only to find natural variation preventing warming from being global.
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Antarctic sea-ice has expanded over the period of continuous satellite monitoring, which seemingly contradicts ongoing global warming resulting from increasing concentrations of greenhouse gasses, says Phys.org.

In a study, published in Nature Climate Change, an international team of scientists from the University of Hawaiʻi at Mānoa, National Oceanic and Atmospheric Administration (NOAA) and South Korea shows that a multi-decadal swing of the tropical sea surface temperatures and its ability to change the atmospheric circulation across large distances is in large part responsible for the observed sea-ice expansion since the late 1970s.

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Ross Ice Shelf, Antarctica


It’s noted that ‘Getting clouds right…is important for calculating how much solar radiation reaches Earth.’ A difference of 10 watts per square metre could be involved in some zones, the researchers found.
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Clouds come in myriad shapes, sizes and types, which control their effects on climate, says Phys.org.

New research led by the University of Washington shows that splintering of frozen liquid droplets to form ice shards inside Southern Ocean clouds dramatically affects the clouds’ ability to reflect sunlight back to space.

The paper, published March 4 in the open-access journal AGU Advances, shows that including this ice-splintering process improves the ability of high-resolution global models to simulate clouds over the Southern Ocean—and thus the models’ ability to simulate Earth’s climate.

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Arctic sea ice [image credit: cbc.ca]


The researchers find ‘a significantly declining AA effect on the millennial time scale’ — but then attempt to link that to anthropogenic forcing in recent times, according to the article at least. That seems illogical if the argument is that humans are playing a part. In any case if the effect has been shown to occur over at least a millennium, that in itself casts doubt on claims that humans must be the prime (or any) cause of the most recent observed changes.
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The recent amplified warming in the Arctic during the last decades has received much attention, says Phys.org.

But how Arctic amplification (AA) has varied on longer time scales and what drives these variations remain unclear.

Recently, a study has provided a new perspective on the AA effect during the past millennium based on the best available paleoclimate data and novel data assimilation methods.

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A portion of the Atlantic meridional overturning circulation [image credit: R. Curry, Woods Hole Oceanographic Institution @ Wikipedia]


Another supposed climate tipping point, popular with the alarm-loving media, floats away? A feature that’s “built into many models” was found not to work as advertised.
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Most simulations of our climate’s future may be overly sensitive to Arctic ice melt as a cause of abrupt changes in ocean circulation, according to new research led by scientists at the University of Wisconsin–Madison.

Climate scientists count the Atlantic Meridional Overturning Circulation (or AMOC) among the biggest tipping points on the way to a planetary climate disaster, says Phys.org.

The Atlantic Ocean current acts like a conveyor belt carrying warm tropical surface water north and cooler, heavier deeper water south.

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Kangerlussuaq Fjord, Greenland [image credit: notsogreen.com]


‘Temperatures and rates of ice sheet melting both peaked in 2012’ – interesting quote from the report. The researchers assume that natural factors are merely impeding the inevitable warming they expect from carbon dioxide emission increases, but assumptions can be risky.
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A puzzling, decade-long slowdown in summer warming across Greenland has been explained by researchers at Hokkaido University in Japan, says Phys.org.

Their observational analysis and computer simulations revealed that changes in sea surface temperature in the tropical Pacific Ocean, thousands of miles to the south, trigger cooler summer temperatures across Greenland.

The results, published in the journal Communications Earth & Environment, will help improve future predictions of Greenland ice sheet and Arctic sea ice melting in coming decades.

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In this new research paper the leading climate models turn out to be either too inaccurate (higher sensitivity) or unalarming (lower sensitivity).
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Plain Language Summary

The last-generation Coupled Model Intercomparison Projects (CMIP6) global circulation models (GCMs) are used by scientists and policymakers to interpret past and future climatic changes and to determine appropriate (adaptation or mitigation) policies to optimally address scenario-related climate-change hazards. However, these models are affected by large uncertainties. For example, their equilibrium climate sensitivity (ECS) varies from 1.83°C to 5.67°C, which makes their 21st-century predicted warming levels very uncertain. This issue is here addressed by testing the GCMs’ global and local performance in predicting the 1980–2021 warming rates against the ERA5-T2m records and by grouping them into three equilibrium climate sensitivity (ECS) classes (low-ECS, 1.80–3.00°C; medium-ECS, 3.01–4.50°C; high-ECS, 4.51–6.00°C). We found that: (a) all models with ECS > 3.0°C overestimate the observed global surface warming; (b) Student t-tests show model failure over 60% (low-ECS) to 81% (high-ECS) of the Earth’s surface. Thus, the high and medium-ECS GCMs do not appear to be consistent with the observations and should not be used for implementing policies based on their scenario forecasts. The low-ECS GCMs perform better, although not optimally; however, they are also found unalarming because for the next decades they predict moderate warming: ΔTpreindustrial→2050 ≲ 2°C.


The signal that wasn’t found could be ‘masked’, researchers suggest. They expected ‘ongoing climate change’ to do something, but maybe it just wasn’t there? Cue more research.
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A new Met Office-led study – reviewing evidence from previous scientific papers and climate models – reveals natural patterns of weakening and strengthening of ocean currents which influence the UK’s weather and climate.

In the North Atlantic lies one of the world’s largest climate mechanisms: a system of currents transporting relatively warm water from the tropics to the poles, with return currents at depth transporting colder, denser water further south.

The transport of heat to the North Atlantic keeps the UK’s climate warmer than other locations at our latitude, says the Met Office.

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Several types of cirrus clouds [image credit: Piccolo Namek @ Wikipedia]


Headline: ‘Airborne study reveals surprisingly large role of desert dust in forming cirrus clouds’. Researchers found ‘Even at low concentrations dust was found to play a big role in controlling cloud properties’. One said: “These results are a striking message to the aerosol and cloud science community, that we need to improve our treatment of dust and cloud formation in climate models to more accurately predict current and future climate.” Not much faith can be put in predictions of the future climate if predicting the present one is known to be inaccurate?
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Every year several billion metric tons of mineral dust are lofted into the atmosphere from the world’s arid regions, making dust one of the most abundant types of aerosol particles in the atmosphere, says Phys.org.

Now, scientists are learning that tiny bits of dust from the hottest and driest parts of the Earth are a surprisingly large driver in forming the delicate, wispy ice clouds known as cirrus in the cold, high-altitudes of the atmosphere.

While scientists have known that desert dust particles can seed certain clouds, the extent of that relationship has been a long-standing question.

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Erie, Pennsylvania [image credit: UK Met Office]


Another modelling problem to add to the list: ‘The models reproduced decreasing snow depth trends that contradicted the observations’. Will any of this get a mention in next week’s new IPCC report?
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Seasonal snow cover plays an important role in the interactions between ground and atmosphere, including energy and hydrological fluxes, thus influencing climatological and hydrological processes, says Phys.org.

Researchers from the Northwest Institute of Eco-Environment and Resources of the Chinese Academy of Sciences and Lanzhou University evaluated the simulated snow depth from 22 CMIP6 models across high-latitude regions of the Northern Hemisphere over the period 1955–2014 by using a high-quality in situ observational dataset.

Related results were published in the Journal of Climate.

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Image credit: NASA


Ice age flooding, recreated in models.
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Earth’s last major ice age locked up gargantuan amounts of water in vast glaciers, says Science Alert.

Once they melted, it was a spectacle to behold as tremendous floods gouged channels into the face of the planet.

The remnants of one of the largest of these ancient deluges are still visible in eastern Washington, in an area now known as the Channeled Scablands.

For a long time, geologists have been struggling to understand the dynamic properties of these floods, until a recent key insight was made.

These ancient glaciers were so large and heavy, they actually tilted Earth’s crust beneath them – when weight was released due to melting, the land would have moved too, changing the course of the megaflood.

Using modeling of ancient megafloods, researchers decided to test whether glacial isostatic adjustment (GIA) – deflections in the crust as heavy chunks of ice form and melt – would affect the routing flow and erosion in two prominent Scabland tracks.

“We used relatively simple, yet plausible, numerical experiments to test whether GIA could have had a substantial impact on flood routing and erosion for two major scabland tracts, Cheney-Palouse and Telford-Crab Creek,” write the authors of the study.

“To this end, we modeled GIA to reconstruct the topography of the Channeled Scabland at different times during the period of Ice Age flooding.”

Up until now, reconstructions of ancient megaflood routing had investigated how other variables would affect them – things like erosion and the movement of sediment, the three-dimensional mechanics of the environment, or how ice dams break, for example.

But they would also base these reconstructions on present-day topography, approximating how past landscapes may have looked.

“People have been looking at high water marks and trying to reconstruct the size of these floods, but all of the estimates are based on looking at the present-day topography,” said lead author Tamara Pico, assistant professor of Earth and planetary sciences at UC Santa Cruz.

Geologists realized that the effects melting glaciers were having on Earth’s crust were also likely playing a role in the routing and behavior of these megafloods.

“GIA caused crustal deformation in the Channeled Scabland with rates up to 10 millimeters per year, orders of magnitude above regional tectonic uplift rates and, therefore, may have influenced flood routing,” note the authors.

“The course of ancient, glacial outburst floods was likely influenced by glacial isostatic adjustment (GIA), and reconstructing these events informs our understanding of how floods shape landscapes on Earth and Mars,” they added.
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The researchers believe the deformation of Earth’s crust due to the expanding and contacting of the ice sheets would have altered the elevation of the landscape by hundreds of meters over this period.

Moving forward, the researchers want to simulate past megaflood events which incorporate the multiple factors that determine their routing.

However, understanding the important role that ice age crustal deformation plays during flood routing and erosion in these ancient megafloods is a step in the right direction.

Full article here.

met-o-update-22
Caution – alarmist brainwashers at work. Never mind the ‘unrealistic’ climate models.
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Thirty-eight emails released under a recent FOI request provide an interesting insight into the way Government science advisers plotted to change Boris Johnson’s mind over the causes of climate change, ahead of a Cabinet Office presentation, says The Daily Sceptic.

The event on January 28th 2020 was led by the Government’s Chief Scientific Officer Sir Patrick Vallance and presented, using 11 slides, by the Chief Scientist of the Met Office, Professor Stephen Belcher.

According to Belcher, the stated goal of the presentation was to “stabilise climate which requires net zero emissions”.

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Can Boris now explain the causes of the Little Ice Age and Medieval Warm Period, pre-dating industrial development?

NOT A LOT OF PEOPLE KNOW THAT

By Paul Homewood

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A slide show that Prime Minister Boris Johnson says helped convince him on climate change has been revealed for the first time.

The slides used to “teach” him about climate science have been released after a Freedom of Information request by UK climate website Carbon Brief.

While Mr Johnson has urged action on climate change, he previously, as a journalist, expressed scepticism.

He called the presentation, given just after he took office, “very important”.

The “teach in”, as it was described in email correspondence, took place in the Cabinet Room of Number 10 Downing Street on 28 January 2020.

It was organised by the office of Sir Patrick Vallance, the government’s chief scientific adviser.

The briefing consisted of 11 slides showing key aspects of climate science and its impacts and the presentation was led by Prof Stephen Belcher, the chief scientist at the Met Office.

https://www.bbc.co.uk/news/science-environment-60203674

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Opposite sea ice trends? [Credits: NASA Goddard Space Flight Center/Joy Ng]


Climate modellers need yet more and bigger computers to stand a chance of eradicating faulty sea ice projections in the polar regions, apparently. Meanwhile, they believe there must be some ‘delay’ in their long-predicted but not (yet?) happening Antarctic sea ice decline. Quote: “Our study supports the hypothesis that climate models and projections of the Antarctic sea ice will be far more reliable as soon as they are capable of realistically simulating a high-resolution ocean, complete with eddies”.
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Despite global warming and the sea-ice loss in the Arctic, the Antarctic sea-ice extent has remained largely unchanged since 1979, says Eurekalert.

However, existing climate model-based simulations indicate significant sea-ice loss, contrary to actual observations.

As experts from the Alfred Wegener Institute have now shown, the ocean may weaken warming around Antarctica and delay sea-ice retreat.

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Antarctica


A key sentence to note in this report says: ‘Half of all carbon dioxide bound in the world’s oceans is found in the Southern Ocean.’ What impact does the outgassing have on the total carbon dioxide content of the atmosphere, which we’re expected to believe is a matter of huge climate concern requiring drastic and expensive measures for decades to come?
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Storms over the waters around Antarctica drive an outgassing of carbon dioxide into the atmosphere, according to a new international study with researchers from the University of Gothenburg. — Phys.org reporting.

The research group used advanced ocean robots for the study, which provides a better understanding of climate change and can lead to better global climate models.

The world’s southernmost ocean, the Southern Ocean that surrounds Antarctica, plays an important role in the global climate because its waters contain large amounts of carbon dioxide.

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Credit: nationalreview.com


Hilarious – somebody must have been watching too many Hollywood fantasy movies. But why on earth is the Met Office paying for such juvenile nonsense?
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It is a bleak forecast even by the Met Office’s standards – the complete collapse of society leaving armed militias and criminal gangs to roam the land unchallenged, says the Daily Mail (via Climate Change Dispatch).

That is one of the doomsday scenarios set out in a report commissioned by the UK’s weather service to model the potential consequences of climate change.

The extraordinary report, called Shared Socioeconomic Pathways and developed for the Government-funded UK Climate Resilience Programme, sets out supposedly ‘plausible futures’ as a result of global warming.

One of those scenarios described by the authors is a surge in ‘Right-wing populism’, resulting in the collapse of ‘political and governance systems.’

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