Archive for the ‘Alarmism’ Category

South Australian blackouts due to over-reliance on wind and solar were predicted 2 years ago

February 13, 2017

I see that in South Australia some people have been complaining about the “record” heat with temperatures of 44ºC. Of course they take this as “evidence” of global warming. Never mind that some 120 years ago without any urban heat effects and without any industrialisation, the temperature reached 48-49ºC. It wasn’t global warming then.

In any event, South Australians and their elected representatives must get used to the fact that they have only themselves – and their political correctness – to blame. Winning greenie points seems to take precedence over common sense.

The SA blackouts caused by unreliable solar and wind were predicted two years ago in the journal Transactions of the Royal Society of South Australia, and every MP in the Parliament was told.

The Telegraph: 

100,000 SA customers blacked out because of reliance on unreliable wind and solar power in our network – more than a third of SA’s generation capacity.

IT is hard to disagree with the blunt assessment of Business SA that South Australia has been caught on electricity planning like a frog in boiling water. The story goes, with mixed results in scientific experiments, that a frog suddenly put into hot water will jump out but if heated slowly it will not figure out the danger.

The state was warned of the electricity-shortage crisis – and consequent blackouts – yet ignored the warnings, according to Business SA executive Anthony Penney.

“The most frustrating aspect of this most recent event is that it was anticipated by many businesses and other energy industry experts well in advance but, like the frog in boiling water, nothing happened in time,” he says.

This week the SA frog boiled. About 100,000 customers were blacked out because of the reliance on unreliable wind and solar power in our network – more than a third of SA’s generation capacity. ……….

Ben Heard, a doctoral researcher at the University of Adelaide also runs environmental non-Government organisation Bright New World – which supports the use of nuclear – explains the problem. He says the SA blackouts caused by unreliable solar and wind were predicted two years ago in the journal Transactions of the Royal Society of South Australia, and every MP in the Parliament was told.

“Back when wind generation was providing only 28 per cent of SA’s electricity supply, we flagged the risk presented by low supply in extreme heat conditions,’’ he says. Mr Heard said it was well known that extreme heat conditions in SA were accompanied by very little wind. “Our expectation at the time was that this would make it impossible to retire other generators from the market because of the security risk. Instead, the generators were allowed to retire, we took the risk, and we have started paying the price.”

Trans. Royal Society of South Australia


“Dilbert” withdraws his support for Berkeley

February 7, 2017

Scott Adams (creator of Dilbert) got his MBA from UC Berkeley but he is not amused by the shenanigans there. He suggests Berkeley is closer to Hitler than the right wing Milo Yiannopoulos they stopped (by rioting).


Berkeley and Hitler

Here’s the best article you are likely to read about the absurdity of calling ANY American president Hitler. This is the sort of persuasion (sprinkled with facts) that can dissolve some of the post-election cognitive dissonance that hangs like a dark cloud over the country. Share it liberally, so to speak. You might save lives.

Speaking of Hitler, I’m ending my support of UC Berkeley, where I got my MBA years ago. I have been a big supporter lately, with both my time and money, but that ends today. I wish them well, but I wouldn’t feel safe or welcome on the campus. A Berkeley professor made that clear to me recently. He seems smart, so I’ll take his word for it.

I’ve decided to side with the Jewish gay immigrant who has an African-American boyfriend, not the hypnotized zombie-boys in black masks who were clubbing people who hold different points of view. I feel that’s reasonable, but I know many will disagree, and possibly try to club me to death if I walk on campus. 

Yesterday I asked my most liberal, Trump-hating friend if he ever figured out why Republicans have most of the Governorships, a majority in Congress, the White House, and soon the Supreme Court. He said, “There are no easy answers.”

I submit that there are easy answers. But for many Americans, cognitive dissonance and confirmation bias hide those easy answers behind Hitler hallucinations. 

I’ll keep working on clearing the fog. Estimated completion date, December 2017. It’s a big job.

As he says, the privileged elite, Trump-haters need to come to terms with the reality that most of the US Governors, both houses of Congress, the White House and most of (soon) the Supreme Court are Republican.


The faking of climate data before the Paris conference

February 5, 2017

The “global temperature” is calculated by dividing the world into a grid, determining the temperature applying to each grid element and then “calculating” (not a simple average) a “global temperature” to apply to the world. The problem is that there are actual measurements (raw data) for just about 20% of the grid elements. These 20% are then used to “fill in” temperatures for all the other grid elements. There are algorithms devised first for “correcting” the raw data, then there are those governing the manner in which the corrected data are to be combined to fill in empty grid elements, and further algorithms to be used when combining all the elements of the grid to give a single “global temperature”. The accuracy of the raw data is only about 0.1ºC while the “global temperature” is presented to 0.001ºC, and differences of the order of 0.001ºC are used to make conclusions for  “policy” decisions. Climategate 1 revealed how data has been cherry picked and fudged for the first time. The deception continues.

Dr John Bates (formerly of NOAA) is now blowing the whistle on how the NOAA has manipulated climate data:

John Bates received his Ph.D. in Meteorology from the University of Wisconsin-Madison in 1986. Post Ph.D., he spent his entire career at NOAA, until his retirement in 2016.  He spent the last 14 years of his career at NOAA’s National Climatic Data Center (now NCEI) as a Principal Scientist, where he served as a Supervisory Meteorologist until 2012.

…….. NOAA Administrator’s Award 2004 for “outstanding administration and leadership in developing a new division to meet the challenges to NOAA in the area of climate applications related to remotely sensed data”. He was awarded a U.S. Department of Commerce Gold Medal in 2014 for visionary work in the acquisition, production, and preservation of climate data records (CDRs). He has held elected positions at the American Geophysical Union (AGU), including Member of the AGU Council and Member of the AGU Board. He has played a leadership role in data management for the AGU.

He has a guest post at Judith Curry’s blog.

Climate scientists versus climate data

by John Bates

A look behind the curtain at NOAA’s climate data center.

I read with great irony recently that scientists are “frantically copying U.S. Climate data, fearing it might vanish under Trump” (e.g., Washington Post 13 December 2016). As a climate scientist formerly responsible for NOAA’s climate archive, the most critical issue in archival of climate data is actually scientists who are unwilling to formally archive and document their data. I spent the last decade cajoling climate scientists to archive their data and fully document the datasets. I established a climate data records program that was awarded a U.S. Department of Commerce Gold Medal in 2014 for visionary work in the acquisition, production, and preservation of climate data records (CDRs), which accurately describe the Earth’s changing environment.

The most serious example of a climate scientist not archiving or documenting a critical climate dataset was the study of Tom Karl et al. 2015 (hereafter referred to as the Karl study or K15), purporting to show no ‘hiatus’ in global warming in the 2000s (Federal scientists say there never was any global warming “pause”). The study drew criticism from other climate scientists, who disagreed with K15’s conclusion about the ‘hiatus.’ (Making sense of the early-2000s warming slowdown). The paper also drew the attention of the Chairman of the House Science Committee, Representative Lamar Smith, who questioned the timing of the report, which was issued just prior to the Obama Administration’s Clean Power Plan submission to the Paris Climate Conference in 2015.

In the following sections, I provide the details of how Mr. Karl failed to disclose critical information to NOAA, Science Magazine, and Chairman Smith regarding the datasets used in K15. I have extensive documentation that provides independent verification of the story below. I also provide my suggestions for how we might keep such a flagrant manipulation of scientific integrity guidelines and scientific publication standards from happening in the future. Finally, I provide some links to examples of what well documented CDRs look like that readers might contrast and compare with what Mr. Karl has provided.

Background …..

Read the whole post here.

Of course the mainstream, politically correct media have no time for this. However David Rose of the Mail on Sunday is one of the few reporters who still has the nerve to question the fanatic, religious orthodoxy on this subject.

Exposed: How world leaders were duped into investing billions over manipulated global warming data 

  • The Mail on Sunday can reveal a landmark paper exaggerated global warming
  • It was rushed through and timed to influence the Paris agreement on climate change
  • America’s National Oceanic and Atmospheric Administration broke its own rules
  • The report claimed the pause in global warming never existed, but it was based on misleading, ‘unverified’ data

The Mail on Sunday today reveals astonishing evidence that the organisation that is the world’s leading source of climate data rushed to publish a landmark paper that exaggerated global warming and was timed to influence the historic Paris Agreement on climate change.

A high-level whistleblower has told this newspaper that America’s National Oceanic and Atmospheric Administration (NOAA) breached its own rules on scientific integrity when it published the sensational but flawed report, aimed at making the maximum possible impact on world leaders including Barack Obama and David Cameron at the UN climate conference in Paris in 2015.

The report claimed that the ‘pause’ or ‘slowdown’ in global warming in the period since 1998 – revealed by UN scientists in 2013 – never existed, and that world temperatures had been rising faster than scientists expected. Launched by NOAA with a public relations fanfare, it was splashed across the world’s media, and cited repeatedly by politicians and policy makers.

But the whistleblower, Dr John Bates, a top NOAA scientist with an impeccable reputation, has shown The Mail on Sunday irrefutable evidence that the paper was based on misleading, ‘unverified’ data.

It was never subjected to NOAA’s rigorous internal evaluation process – which Dr Bates devised.

His vehement objections to the publication of the faulty data were overridden by his NOAA superiors in what he describes as a ‘blatant attempt to intensify the impact’ of what became known as the Pausebuster paper. …….

NOAA data manipulation (from David Rose - Mail on Sunday)

NOAA data manipulation (from David Rose – Mail on Sunday)

There will be more whistle-blowers now stepping out from behind the woodwork.


97% of “climate scientists” thought Trump couldn’t win

December 18, 2016

97% of the UK media thought Brexit would lose.

97% of US political pundits thought Trump couldn’t win.

97% of polling models had an inbuilt, politically correct, confirmation bias.

97% of the US media thought Clinton would trounce Trump.

97% of the politically correct think climate is science.

97% of AGW fanatics believe the sun does not drive climate but that man does.

97% of climate funding goes to the religiously correct.

97% of “climate science” is religious belief.

97% of climate models have an inbuilt, religiously correct, confirmation bias.

97% of “climate scientists” thought Trump would be trounced.

97% of “climate scientists” are charlatans.


Trump’s choice for Energy Secretary will be a coal supporter

December 12, 2016


It is reported that Donald Trump has a short-list of four for Energy Secretary. What seems clear is that whoever it is will be making coal jobs a priority. One of the four (Rick Perry) would be a fierce opponent of  all the fake science masquerading as “climate science”, while two (Heidi Heitkamp and Joe Manchin) are coal protectors rather than climate change opponents. The fourth (Ray Washburne) has been involved primarily in economic and finance matters and has (for me) unknown positions about coal and AGW. But he is from Texas and is unlikely to ignore the bottom line (which is of no consequence for the AGW orthodoxy).

Bloomberg: Donald Trump has narrowed his search for energy secretary to four people, with former Texas Governor Rick Perry the leading candidate. People familiar with the president-elect’s selection process said two Democratic senators from energy-producing states — Heidi Heitkamp of North Dakota and Joe Manchin of West Virginia — are also in the mix, along with Ray Washburne, a Dallas investor and former chairman of the Republican National Committee.

If Trump picks any of the four he’ll break with recent tradition of putting scientists at the top of the Energy Department. Among other things, the agency is responsible for policies on the safe handling of nuclear material and on emerging energy technologies.

A quick search gives the positions of the four on coal production and the global warming fantasy.

Rick PerryRick Perry said Wednesday morning that he does not believe in global warming science and suggested it is grounded in scientists manipulating data for financial gain. …….. Perry said scientists are coming forward almost daily to question “the original idea that man-made global warming is what is causing the climate to change.” He said the climate is changing but that it has been changing “ever since the earth was formed.” ……….. Perry added that “the issue of global warming has been politicized,” and argued that America should not spend billions of dollars addressing “a scientific theory that has not been proven, and from my perspective is more and more being put into question.”

Rick Perry could be expected to be quite active in cleaning out the muck in the Department of Energy Climate Change stables.

Heidi Heitkamp: I applaud the President’s efforts to address climate change and its effects. …… However, several of the initiatives introduced today by the President, while not new, amplify the Administration’s continuing war on coal and coal-fired power. While the President claims to believe in an all-of-the-above energy policy, he consistently fails to step-forward and truly commit to such a policy. Instead the Administration continues developing regulations that do nothing more than choke off good-paying American jobs, and threatening millions of Americans with the loss of a reliable and affordable energy source. Instead of taking this route, we need to find a path forward for the coal industry and coal-fired power by encouraging continued investments in new and existing technologies to further reduce emissions through clean coal technology projects including commercially scalable carbon capture and sequestration. 

Heitkamp is only concerned about jobs and will subordinate her thinking to that end. Her apparent belief in carbon capture and sequestration though suggests that her logical thinking is a little suspect. To be kind, it may just be her attempt to save coal jobs and not any strong belief in nonsense technology which which has no real purpose and which has a fundamental “floor” energy cost which makes it meaningless.

Joe ManchinSenator Joe Manchin (D-WV) went on Fox News on Wednesday to slam President Obama’s renewed push to take action on climate change.However, returning to the refrain that Obama has declared a “war on coal” appears not to be enough this time. Now, the coal-backed senator has upgraded his rhetoric to a “war on America.”

STEVE DOOCY (HOST): The President of the United States declared a war on coal and a war on jobs and essentially a war on West Virginia.

MANCHIN: Well, really a war on America. When you look at it from that standpoint, 8 billion-tons of coal is being burned in the world as we speak. The United States of America consumes about one billion tons. Now, what’s going to happen to the other 7 billion-tons? What’s going to happen to the countries that are consuming and using 7 billion and it’s increasing rapidly? Nothing is being done there. We have done more to clean the environment than ever in the last two decades. And there is more that can be done.

Manchin, like Heitkamp, is primarily concerned about jobs in the coal industry. He has not dared, politically, to be heretical about global warming orthodoxy but has fought for coal jobs.

Ray WashburneMr. Ray W. Washburne has been the Chief Executive Officer of Charter Holdings since 1990 and its President. Mr. Washburne has been National Finance Chairman at Republican National Committee Inc., since February 2013. He is a Managing Partner at HP Village Partners Ltd., and served as Managing Director. He was the Chairman of Charter Holdings since 1990. He also serves on the board of directors for M Crowd Restaurant, which he co-founded in 1991. He serves as Director of Baylor Health Care System Foundation. He has been Director of Entrust Inc. since June 5, 2006. He has been an Independent Director of Veritex Holdings, Inc., since 2009 and serves as Director of Veritex Community Bank. Mr. Washburne is also a Director for Colonial Bank, Southern Methodist University-21st Century Council, and Dallas Citizens Council. He is an Adjunct Professor at SMU’s Cox School of Business and graduated from Southern Methodist University (“SMU”) in 1984.

It is not apparent that Washburne has any strong position on coal or energy or AGW. Nevertheless he can be expected to have a clear view of the bottom line and therefore, not a great supporter of subsidising non-commercial technologies for religious or ideological reasons.

If I had to bet, I would put a small amount of money on Rick Perry.

Cold weather in Alberta gives record electricity consumption (thank goodness for coal)

December 11, 2016

Canada has been experiencing some rather cold weather with windchill factors down to -40°C.

Environment Canada has issued an extreme cold warning starting in northwestern B.C., going west through central and northern Alberta, central and southwestern Saskatchewan and southeastern Manitoba. By Friday afternoon, the extreme cold warning extended to most of central and northern Alberta, including High Level and Fort Chipewyan and as far south as Airdrie and Cochrane.

The Alberta Electric System Operator AESO reports record electricity consumption due to the cold spell.

Extremely cold weather across Alberta this week contributed to the province setting three records in a row for electricity consumption.

On December 8, 2016 between 5-6 p.m., Alberta was using a record hourly average amount of electricity at 11,442 MW. This surpassed the December 7 record of 11,404 MW, and the December 5 record of 11,400 MW.

The new winter peak usage was set due to cold weather, reduced daylight hours and the convergence of Christmas lighting load at homes, businesses, malls and buildings across the province. Another factor that contributed was the low market price for electricity – this prevented price sensitive industrial facilities from going offline during peak hours. The average wholesale price for electricity during that peak hour was approximately $30/MWh.

In Alberta the installed capacity and energy generation shows the reliance on fossil fuels in general and coal in particular. It’s a good thing they have coal to fall back on.




74 questions from the Trump transition team which are bothering the Department of Energy

December 10, 2016

Whatever one may think of Trump, his transition team’s questions for the Department of Energy are penetrating. They are causing some little worry among the adherents of the man-made global warming religion.

Willis Eschenbach has the list of questions and his comments over at WUWT.


Man-made climate change (actually the lack of such), vast grants to companies which go bankrupt in the night, jaunts to resorts for climate meetings, prolonging nuclear power …. are all apparently within the sights of the transition team.

The questions and Willis Eschenbach’s comments are reproduced below

Questions for DOE

This memo, as you might expect, is replete with acronyms. “DOE” is the Department of Energy. Here are the memo questions and my comments.

1. Can you provide a list of all boards, councils, commissions, working groups, and FACAs [Federal Advisory Committees] currently active at the Department? For each, can you please provide members, meeting schedules, and authority (statutory or otherwise) under which they were created? 

If I were at DOE, this first question would indeed set MY hair on fire. The easiest way to get rid of something is to show that it was not properly established … boom, it’s gone. As a businessman myself, this question shows me that the incoming people know their business, and that the first order of business is to jettison the useless lumber.


Reading University shows Antarctic ice increased over last 3 decades and is largely unchanged over 100 years

November 24, 2016

You cannot have “global” warming which applies differently to different parts of the globe. If man-made CO2 is having any significant effect on “global” temperature it must be an effect that is visible in both the Arctic and the Antarctic. Even if all the Arctic ice melts but the Antarctic ice does not then “global” warming is clearly not “global”.

A new study by Reading University shows that Antarctic ice is largely unchanged over 100 years and increasing over the last 3 decades. The man-made “global” warming theory is just not possible with these results.

Research article
21 Nov 2016

Estimating the extent of Antarctic summer sea ice during the Heroic Age of Antarctic Exploration

Tom Edinburgh1,a and Jonathan J. Day11Department of Meteorology, University of Reading, Reading, UK
acurrently at: Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, UK

Abstract. In stark contrast to the sharp decline in Arctic sea ice, there has been a steady increase in ice extent around Antarctica during the last three decades, especially in the Weddell and Ross seas. In general, climate models do not to capture this trend and a lack of information about sea ice coverage in the pre-satellite period limits our ability to quantify the sensitivity of sea ice to climate change and robustly validate climate models. However, evidence of the presence and nature of sea ice was often recorded during early Antarctic exploration, though these sources have not previously been explored or exploited until now. We have analysed observations of the summer sea ice edge from the ship logbooks of explorers such as Robert Falcon Scott, Ernest Shackleton and their contemporaries during the Heroic Age of Antarctic Exploration(1897–1917), and in this study we compare these to satellite observations from the period 1989–2014, offering insight into the ice conditions of this period, from direct observations, for the first time. This comparison shows that the summer sea ice edge was between 1.0 and 1.7° further north in the Weddell Sea during this period but that ice conditions were surprisingly comparable to the present day in other sectors.

Citation: Edinburgh, T. and Day, J. J.: Estimating the extent of Antarctic summer sea ice during the Heroic Age of Antarctic Exploration, The Cryosphere, 10, 2721-2730, doi:10.5194/tc-10-2721-2016, 2016.

Ice observations recorded in the ships’ logbooks of explorers such as the British Captain Robert Scott and Ernest Shackleton and the German Erich von Drygalski have been used to compare where the Antarctic ice edge was during the Heroic Age of Antarctic Exploration (1897-1917) and where satellites show it is today.

The study, published in the European Geosciences Union journal The Cryosphere, suggests Antarctic sea ice is much less sensitive to the effects of climate change than that of the Arctic, which in stark contrast has experienced a dramatic decline during the 20th century. ……

……. Jonathan Day, who led the study, said: “The missions of Scott and Shackleton are remembered in history as heroic failures, yet the data collected by these and other explorers could profoundly change the way we view the ebb and flow of Antarctic sea ice.

“We know that sea ice in the Antarctic has increased slightly over the past 30 years, since satellite observations began. Scientists have been grappling to understand this trend in the context of global warming, but these new findings suggest it may not be anything new.

“If ice levels were as low a century ago as estimated in this research, then a similar increase may have occurred between then and the middle of the century, when previous studies suggest ice levels were far higher.”

The new study published in The Cryosphere is the first to shed light on sea ice extent in the period prior to the 1930s, and suggests the levels in the early 1900s were in fact similar to today, at between 5.3 and 7.4 million square kilometres. Although one region, the Weddell Sea, did have a significantly larger ice cover.

Published estimates suggest Antarctic sea ice extent was significantly higher during the 1950s, before a steep decline returned it to around 6 million square kilometres in recent decades.

The research suggests that the climate of Antarctica may have fluctuated significantly throughout the 20th century, swinging between decades of high ice cover and decades of low ice cover, rather than enduring a steady downward trend.


“Adjusting” temperatures is a political exercise in a politicised “science”

November 24, 2016

To pretend that politicised science does not exist is to be naive. To state as a religious conviction that man-made CO2 is causing global warming is little different to the religiously expressed beliefs by politically correct media that Brexit would not happen or that Trump could not win. Climate “scientists” and their gullible followers need to remember that all beliefs can only exist in the space of ignorance.

I dislike algorithms for “calculating” an artificial “global temperature” by “adjusting” and “weighting” raw data to suit pre-conceived notions of what final result should be. It gets worse when the “adjustments” about past temperatures are variable and are themselves “adjusted” every year. The reports about every year being hotter than the last are actually just a statement that “adjustments” every year are greater than the last.

I reproduce Tony Heller’s post about the US temperatures in realclimatescience:

NOAA Adjustments Correlate Exactly To Their Confirmation Bias

Thermometers show the US cooling since about 1920, but NOAA massively cools the past to create the appearance of a warming trend.


These adjustments make a spectacular hockey stick of data tampering.


When plotted against atmospheric CO2, the correlation is almost perfect.  NOAA is tampering with the data exactly to match their theory.



Judith Curry’s guide to climate models

November 13, 2016

Judith Curry’s guide to climate models.

Well worth reading.

Though written for lawyers, it might even be tough for many lawyers. However politicians should get their “science” aides to read, digest and summarise it for them (it would be far too ambitious to expect the politicians to be able to read so much, understand it or to digest so much in one go).

For me, the real issue with GCM’s is not that the modelling is done but that they are used for policy making. Assumed sensitivities are effectively used to fit the results for the immediate past. The forced fit is then taken as proof that the assumptions are true and are then projected into the future. The claimed objective of the resultant policies can neither be monitored nor measured.

Climate models for lawyers

by Judith Curry

I have been asked to write an Expert Report on climate models.

No, I can’t tell you the context for this request (at this time, anyways).  But the audience is lawyers.

Here are the specific questions I have been asked to respond to:

  1. What is a Global Climate Model (GCM)?
  2. What is the reliability of climate models?
  3. What are the failings of climate models?
  4. Are GCM’s are a reliable tool for predicting climate change?

I’ve appended my draft Report below. I tried to avoid giving a ‘science lesson’, and focus on what climate models can and can’t do, focusing on policy relevant applications of climate models.  I’ve tried write an essay that would be approved by most climate modelers; at the same time, it has to be understandable by lawyers. I would greatly appreciate your feedback on:

  • whether you think lawyers will understand this
  • whether the arguments I’ve made are the appropriate ones
  • whether I’m missing anything
  • anything that could be left out (its a bit long).


What is a Global Climate Model (GCM)?

Global climate models (GCMs) simulate the Earth’s climate system, with modules that simulate the atmosphere, ocean, land surface, sea ice and glaciers.  The atmospheric module simulates evolution of the winds, temperature, humidity and atmospheric pressure using complex mathematical equations that can only be solved using computers. These equations are based on fundamental physical principles, such as Newton’s Laws of Motion and the First Law of Thermodynamics.

GCMs also include mathematical equations describing the three-dimensional oceanic circulation, how it transports heat, and how the ocean exchanges heat and moisture with the atmosphere. Climate models include a land surface model that describes how vegetation, soil, and snow or ice cover exchange energy and moisture with the atmosphere. GCMs also include models of sea ice and glacier ice.

To solve these equations on a computer, GCMs divide the atmosphere, oceans, and land into a 3-dimensional grid system (see Figure 1). The equations and are then calculated for each cell in the grid repeatedly for successive time steps that march forward in time throughout the simulation period.


Figure 1. Schematic of a global climate model.

The number of cells in the grid system determines the model ‘resolution.’ Common resolutions for a GCM include a horizontal resolution of about 100-200 km, a vertical resolution of about 1 km, and a time stepping resolution that is typically about 30 minutes. While GCMs represent processes more realistically at higher resolution, the computing time required to do the calculations increases substantially at higher resolutions. The coarseness of the model resolution is driven by the available computer resources, and tradeoffs between model resolution, model complexity and the length and number of simulations to be conducted.

Because of the relatively coarse spatial and temporal resolutions of the models, there are many important processes that occur on scales that are smaller than the model resolution (such as clouds and rainfall; see inset in Figure 1). These subgrid-scale processes are represented using ‘parameterizations.’ Parameterizations of subgrid-scale processes are simple formulas based on observations or derivations from more detailed process models. These parameterizations are ‘calibrated’ or ‘tuned’ so that the climate models perform adequately when compared with historical observations.

The actual equations used in the GCM computer codes are only approximations of the physical processes that occur in the climate system. While some of these approximations are highly accurate, others are unavoidably crude. This is because the real processes they represent are either poorly understood or too complex to include in the model given the constraints of the computer system. Of the processes that are most important for climate change, parameterizations related to clouds and precipitation remain the most challenging, and are the greatest source of disagreement among different GCMs.

GCMs are used for the following purposes:

  • Simulation of present and past climate states to understand planetary energetics and other complex interactions
  • Numerical experiments to understand how the climate system works. Sensitivity experiments are used to turn off, constrain or enhance certain physical processes or external forcings (e.g. CO2, volcanoes, solar output) to see how the system responds.
  • Understanding the causes of past climate variability and change (e.g. how much of the change can be attributed to human causes such as CO2, versus natural causes such as solar variations, volcanic eruptions, and slow circulations in the ocean).
  • Simulation of future climate states, from decades to centuries, e.g. simulations of future climate states under different emissions scenarios.
  • Prediction and attribution of the statistics extreme weather events (e.g. heat waves, droughts, hurricanes)
  • Projections of future regional climate variations to support decision making related adaptation to climate change
  • Guidance for emissions reduction policies
  • Projections of future risks of black swan events (e.g. climate surprises)

The specific objectives of a GCM vary with purpose of the simulation. Generally, when simulating the past climate using a GCM, the objective is to correctly simulate the spatial variation of climate conditions in some average sense.  When predicting future climate, the aim is not to simulate conditions in the climate system on any particular day, but to simulate conditions over a longer period—typically decades or more—in such a way that the statistics of the simulated climate will match the statistics of the actual future climate.

There are more than 20 climate modeling groups internationally, that contribute climate model simulations to the IPCC Assessment Reports. Further, many of the individual climate modeling groups contribute simulations from multiple different models. Why are there so many different climate models? Is it possible to pick a ‘best’ climate model?

There are literally thousands of different choices made in the construction of a climate model (e.g. resolution, complexity of the submodels, parameterizations). Each different set of choices produces a different model having different sensitivities. Further, different modeling groups have different focal interests, e.g. long paleoclimate simulations, details of ocean circulations, nuances of the interactions between aerosol particles and clouds, the carbon cycle. These different interests focus computational resources on a particular aspect of simulating the climate system, at the expense of others.

Is it possible to select a ‘best’ model? Well, several models generally show a poorer performance overall when compared with observations. However, the best model depends on how you define ‘best’, and no single model is the best at everything. The more germane issue is to assess model’s ‘fitness for purpose’, which is addressed in Sections 2-4.

The reliability of climate models ……

Read the whole post



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