Presentation by Ross McKitrick: is a worst case scenario (of Climate Change) really bad?

Reposted from Clintel

Ross McKitrick, the Canadian economics professor who publishes regularly in climate journals, gave an online talk for the Irish Climate Science Forum and the international CLINTEL Foundation (of which I am the cofounder). I have some sort of special bond with both McKitrick and McIntyre, because back in 2004, when I was an editor for a Dutch monthly science magazine, my editor in chief told me I had to write an article about a socalled hockey stick graph. I had never written about climate change and so was completely blank. Two months later (and a lot of research), on the day that McIntyre and McKitrick published their critique on the hockey stick in GRL, my article about this saga came out (both in Dutch and in English). It was my entree in the climate debate and thanks mainly to the (lack of) response to this critique of M&M I became intrigued by the climate discussion, quit my job and started working fulltime on the climate issue. And I am still stuck in it.

So I have followed the work of McKitrick pretty closely throughout the years. He has the wonderful gift to be able to do both deep scientific and technical/mathematical work and get this published in high profile scientific journals (often after long battles with reviewers) and at the same time can write essays and op-eds (mainly for the Financial Post in Canada) that are easy to understand for anyone. In presentations he sounds somewhat unemotional but everything he says is well-thought-out.

So let’s talk about his presentation (a 45 minutes recording of the talk is available here) which was not about the physical climate science debat this time but about climate policy: “Climate Policy – When Emotion Meets Reality”. The key question in the talk was: why is it so difficult to do something against CO2? McKitrick provided the answers in this slide:

These six points were each discussed in more detail during the talk. I will just focus on a few remarks that draw my attention. The most important one for me was point 3: “Emissions tied to fossil use which is essential for economic growth and development.” McKitrick explained that under socalled worst case scenarios people tend to focus on the climate effects only. They forget to look at the economic side of this scenario and that paints a spectacular view. Under this scenario people in developing countries will be 70 times (!) richer around 2100 and will have on average a yearly income of 70.000$. That is they will be considerably richer than we are right now. What this means is that by that time every development problem known to humanity will be solved. Mckitrick joked that the main job loss at the time will be in the foreign aid sector.

The question then of course is how catastrophic the climate consequences will be under this scenario. McKitrick then started to show some of his own work about the long track record of overestimation of both trends in CO2 and trends in temperature forecasts. As the the latter are well-known to most readers, let’s for this moment focus on the former. McKitrick showed this graph:

Source: Hausfather, Z., Drake, H., Abbott, T. and Schmidt, G. (2019) Evaluating the performance of past climate model projections. Geophysical Research Letters doi: 10.1029/2019GL085378.

As you can see the real CO2 concentration in the atmosphere ‘hugs’ the bottom end of the forecast range (after decades of forecasts). McKitrick added this will again be the case in the upcoming AR6 report. He also showed the overestimation of temperature trends.

He then moved on to the cost of abatement (reduction), first emphasizing that people often have a wrong impression of the potential of abatement:

People tend to believe that all costs related to global warming can be avoided (the left blue bar) if only we stopped emitting CO2. However this isn’t the case. After decades of research and measurements and after a steady rise in CO2 no trends are visible in for example hurricanes and flooding (two extremes that McKitrick mentioned). So damage due to such events will happen, even (or also) after abatement. The potential benefit of climate policy is therefore much smaller (the small white box at the top of the right blue bar).

And it gets better and better. McKitrick with colleagues published two very interesting papers in 2017 and 2019 about the socalled Social Cost of Carbon, which reflects the extra cost for society of emitting one extra ton of CO2. In the 2017 paper they used empirically constrained estimates for climate sensitivity (adapted from a paper by Nic Lewis and Judith Curry) instead of much higher model based estimates. The effect on the Social Cost of Carbon was this:

In the second paper in 2019 they added on top of this the additional benefits of CO2 for agriculture. The Social Cost of Carbon then more or less drops to zero or even negative values depending on the discount rate used. What does this all mean? McKitrick: “The CO2 benefits greatly outweigh the climate costs.”

With uncertain climate effects, very costly abatement policies (applies both for Kyoto and Paris), overestimation of both the CO2 and temperature trends, low to zero estimates for the Social Cost of Carbon (if you use observational estimates for climate sensitivity and take into account the benefits of higher CO2 levels for agriculture), there is only one conclusion possible: “We are on pretty safe ground to prioritize economic growth over very ambitious climate policies”.

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Tom Halla
May 14, 2021 10:19 am

Doing something expensive and probably counterproductive is so leftist.

James Donald Bailey
Reply to  Tom Halla
May 14, 2021 12:22 pm

True, but so is doing something blatantly harmful to others. They know that they can’t stop the use of carbon fuels without impoverishing people, putting them back decades or even centuries of improvements to life. And they even dismantle carbon free nuclear power at the same time.

And everybody will be even worse off if they succeed in establishing global control through this phony climate emergency.

Gary Pearse
Reply to  Tom Halla
May 14, 2021 1:56 pm

Tom, 90 trillion for converting the US alone to a ‘carbon free’ energy future and that doesnt count the enormous costly damage to the economy and cost of living.

I like a physical picture for appreciating such magnitudes of costs. The distance from earth to the sun is 15 trillion centimeters. This is also the approximate length of one trillion US dollar bills laid end to end. 90 trillion would therefore equal in miles 45 trips to the sun and back. That’s got to hurt a lot of people!

Reply to  Gary Pearse
May 14, 2021 4:26 pm

You are clearly not a miner or employed in the mining industry yet.

As humanity wanders down the path of righteousness toward an energy future entirely dependent on the weather, more and more people will be employed in the industries that source the raw materials for wind turbines, solar panels and batteries.

The miners will rule the world. The woke miners are abandoning dirty thermal coal and seeking out the minerals of the future that will source the copper, iron ore, aluminium, lithium, neodymium and a horde of other materials needed to electrify the world.

Dave Andrews
Reply to  RickWill
May 15, 2021 7:22 am

You are right. The IEA have just published a new report ‘The Role of Critical Minerals in Clean Energy Transitions’ the following extracts are from the Executive Summary.

“A typical electric car requires six times the mineral inputs of a conventional car, and an onshore wind plant requires nine times more mineral resources than a gas fired plant. Since2010, the average amount of minerals needed for a new unit of power generation capacity has increased by 50% as the share of renewables has risen.”

“a concerted effort to reach the goals of the Paris Agreement…… would mean a quadrupling of mineral requirements for clean energy technologies by 2040. An even faster transition to net zero by 2050 would require six times more mineral inputs in 2040 than today.”.

Reply to  Tom Halla
May 14, 2021 2:35 pm

Oh, boy. You are deluded if you think this is only on the left. It’s hard to find a right-wing politician in the world who isn’t a warmist, too.

Tom Halla
Reply to  Thylacine
May 14, 2021 2:51 pm

Most of the opposition to the CAGW scenario comes from the right. There are a few people I can think of, like GW Bush or Boris Johnson, who are on the right but choose to suck up to the mostly leftist green blob.

Gary Pearse
Reply to  Thylacine
May 14, 2021 2:56 pm

Thylacine, you are probably from Europe. In America, the left (Democrats) are are even to the right of your ‘right’. Cameron, May, Bojo are all left of center crowded in policies without a difference.

The crop of polies in waiting, will however, occupy the totally vacant right of the spectrum. It’s already happened in a few EU countries and France has a credible civil war threat that would be a world changer politically.

Bob Hunter
Reply to  Gary Pearse
May 14, 2021 3:28 pm

IMO, many political leaders support climate change alarmism and its “shoddy” science because they come from areas with very little fossil fuel reserves left. ie Europe or the base for the US Democrat Party or Canada’s Liberal Party. Of course, developing countries love the handouts promised in the Paris Climate Accord.

Reply to  Bob Hunter
May 14, 2021 5:01 pm

All these areas have LOTS of fossil fuels left. Germany coal, Canada oil, the US oil and coal, including NY.

Rory Forbes
Reply to  Drake
May 14, 2021 5:25 pm

In Canada we have coal, oil and gas in abundance … some of the largest reserves on the planet. We simply have a history of returning to incompetent governments … because they promise free stuff to the immigrants.

Izaak Walton
Reply to  Rory Forbes
May 14, 2021 7:56 pm

Including land stolen from the native Americians.

Rory Forbes
Reply to  Izaak Walton
May 14, 2021 8:45 pm

There isn’t a square inch of land on his planet that wasn’t “stolen” from some culture at some time. The “First Nations” regularly “stole” land from each other. Most of them had no concept of land ownership. Residency does not imply ownership. Apart from that, I was speaking about reserves of coal, oil and gas. Your comment is a non sequitur … but you’re no stranger to logical fallacies.

Tom Abbott
Reply to  Izaak Walton
May 15, 2021 5:47 am

Native Americans who stole it from other native Americans.

Who are the original owners?

At one time the Americas were devoid of humans. So, when the first human sets foot on the soil of the Americas, does that mean that he and his decendants own the entire continent for all time?

Last edited 1 month ago by Tom Abbott
Reply to  Izaak Walton
May 15, 2021 11:06 am

Not to be too picky, but since they didn’t evolve here, when did they arrive?

And who was displaced then?

Bob Hunter
Reply to  Drake
May 14, 2021 5:28 pm

Vast majority of Germany’s coal is Lignite
US Democrat Base in The Northeast and along the West Coast have little coal and oil left
Canada Liberal base in Ontario, Quebec, Maritimes and Vancouver don’t either
However, Vancouver does allow 11 million tones Wyoming & Montana Thermal coal leave its port for Asia every year carbon tax free

Rory Forbes
Reply to  Bob Hunter
May 14, 2021 8:55 pm

“Some estimates put the country’s remaining reserves at as much as 10% the global total. Perhaps 12 billion tonnes of it thought to be minable in British Columbia (approx. 83% of Canada’s total), concentrated in the mountainous Kootenays in the southeast, the Rocky Mountain foothills in the northeast, or on the east coast of Vancouver Island.”

Bob Hunter
Reply to  Rory Forbes
May 14, 2021 10:15 pm

Maybe you should educate yourself
There are 3 primary types of coal

Metallurgical is used for making steel

re Climate Change , thermal coal is the coal type used in power generation plants. ie the type the alarmists are against

And if you had read a little further from the document you got the quote from, you would have seen most of BC’s coal is metallurgical

Rory Forbes
Reply to  Bob Hunter
May 14, 2021 10:59 pm

Maybe you should educate yourself

I didn’t really need a further display of your pomposity. I’m very satisfied with my education so far.

you would have seen most of BC’s coal is metallurgical

Where did I imply that it wasn’t? I fail to see what you’re trying to argue against.

Bob Hunter
Reply to  Rory Forbes
May 15, 2021 7:58 am

The climate alarmists are focused on stopping thermal coal for power generation

Rory Forbes
Reply to  Bob Hunter
May 15, 2021 10:25 am

Climate alarmists are generally UNfocused cretins who are trying to stop all “fossil fuels” and coal specifically, of all types. They have never been particularly strong on either rationality or science in general.

Bob Hunter
Reply to  Rory Forbes
May 15, 2021 11:40 am

Their focus has been on Thermal Coal

Rory Forbes
Reply to  Bob Hunter
May 15, 2021 12:26 pm

Nonsense! I have been following this crap for nearly 40 years. I haven’t seen one mention of “thermal” coal before your comments. Yes, I know the difference, but I can assure you; none of the politicians nor do any of the most prominent AGW true believers promoting this fraud either know or care.

Their focus has been on Thermal Coal

No, the focus has been on ALL fossil fuels.

Bob Hunter
Reply to  Rory Forbes
May 15, 2021 4:58 pm

Crap? 40 yrs? Clearly you don’t understand. Re Coal. It is the coal powered generation stations the green lobby has focused on. Coal powered generation stations use thermal coal And I too have followed the fossil fuel industries for more than 40 yrs As a CFO living through the NEP, to one of our divisions having the world’s largest mining company being our partner for 30 yrs in their biggest coal mine in the US. I have seen other industries getting grants &!tax credits undercutting our market. My whole career I lived through Peak Oil claims.
Suffice it to say I know what I speak of, and just maybe you haven’t put the puzzle together.

Rory Forbes
Reply to  Bob Hunter
May 15, 2021 9:09 pm

Suffice it to say I know what I speak of, and just maybe you haven’t put the puzzle together.

There’s no puzzle … you just think you know what you speak of. The “green lobby” focuses on what gets them the best results for their cause. That is almost always achieved by lying, cheating, fraud and various appeals to logical fallacies. Clearly, you’ve spent so much times working for acronyms you have no idea what the real world is doing.

It is the coal powered generation stations the green lobby has focused on.

The “green lobby” are almost universally, progressives or Marxists. They don’t give a fart in a hurricane about the finer points of climate or energy production. Their goal is destroying our economy. Destroying steel production (coking coal) is just as useful.

Jimmie Dollard CJ52
Reply to  Rory Forbes
May 16, 2021 5:04 am

Na! It is worse than that. The green Marxist are against anything that works to make life better-nuclear, GMO, modern agriculture, fossil fuels, pipelines, increasing GDP to overcome poverty, meat, dairy, vaccinations and modern medicine, reliable electricity in undeveloped countries, etc. Their claim that modern civilization is destroying the earth is not supported by facts. Any measure of world health improves with increasing GDP (also with increasing use of fossil fuels and CO2).

Rory Forbes
Reply to  Jimmie Dollard CJ52
May 16, 2021 10:07 am

It seems that the average person is completely blind to the extremes the Left will go to manifest their agenda. It isn’t only the economic attacks they promote. They have also been attacking our children and our language systematically. They are undermining the fabric of Western civilization with a well planned attack.

Those who understand these things and speak up about it are immediately gas-lighted, called a conspiracy theorist and cancelled.

Bob Hunter
Reply to  Rory Forbes
May 16, 2021 10:41 am

The CO2 green lobby has focused the vast majority of their time and resources on Thermal Coal & PNG To say any different is a misrepresentation

My last word

Rory Forbes
Reply to  Bob Hunter
May 16, 2021 11:08 am

My last word

What a relief. I thought you were never going to stop embarrassing yourself with nonsense.

Reply to  Gary Pearse
May 15, 2021 3:47 am

Thylacine is the scientific name for the Tasmanian tiger which once also existed on mainland Australia (likely killed off by the dingos brought to Australia by settlers from PNG around 3000BC -there were no dingos in Tasmania). I suggest he/she is talking about the poor politics -left & middle socialists in Australia and New Zealand who also are going along with the climate rubbish. Ardern in NZ wants to ruin the country by taxing farmers for having diary cattle and sheep which may burp & fart that dangerous methane. Next she might want to tax people for breathing out CO2 while bowing to Xi in China.

Reply to  Thylacine
May 14, 2021 3:19 pm

Right on the button! We who try to stick to truth and science, rational thought, have been abandoned by all political players!

Rory Forbes
Reply to  PCman999
May 14, 2021 5:28 pm

Th entire idea of human climate causation abandoned real science a generation ago. It has been solely political ever since. They have been simply making shit up and the media expands on that (as they did with the lies they invented about the Trump administration).

Dr Ken Pollock
May 14, 2021 10:21 am

Very convincing from a highly reputable source. Note it agrees with Bjorn Lomberg as in “False Alarm” and Michael Shellenberger in “Apocalypse Never”. Any chance politicians will take any notice? Sadly it takes a lot of courage to decide to be out of step with the herd…

Reply to  Dr Ken Pollock
May 14, 2021 11:12 am

I loved Trump but even he wouldn’t take on these climate alarmists bozos.

You can tell people over and over about the benefits of CO2, but it will fall on deaf ears. These people feel like it’s bad and that is all that matters to them.

Reply to  Derg
May 14, 2021 12:35 pm

Those deaf ears need some CO2 therapy …

Reply to  Derg
May 14, 2021 5:04 pm

TRUMP! would not touch the third rail of republican base support, the ethanol subsidies for farmers and refiners.

Next time, with no second term to run for, he will go scorched earth and clean out the swamp, I hope!

Reply to  Drake
May 14, 2021 5:14 pm

You are right Drake ethanol subsidies are another folly

Tom Abbott
Reply to  Drake
May 15, 2021 5:53 am

I like the way you are thinking, Drake. 🙂

I think if Trump got re-elected he would go after the ethanol. I would be cheering him on.

Ron Long
May 14, 2021 10:29 am

Great posting. These Reality Checks are starting to pile up. On a personal level, as the years add up, I am more in favor of more heat and less in favor of more cold. Bring it.

Reply to  Ron Long
May 14, 2021 3:31 pm

Right on – I wish GW were true, even some of the most dramatic imaginative scenarios. 2 or 3 degrees warmer by 2100 would barely be noticeable (as the increase affects mostly the nighttime lows if co2 insulation is correct) but would be greatly appreciated nonetheless. The extra co2 and the slightly longer growing season will have dramatically positive affects on agricultural production and wildlife in general. Bring it on!

Joseph Zorzin
May 14, 2021 10:31 am

I’ll have to presume Bill Gates doesn’t read this blog. Too bad. I just started his climate book and I’m very disappointed. He and other “big shots” who easily get the attention of the MSM need to acknowledge that climate skepticism doesn’t deserve to be ignored. It’s just not smart to do so.

Reply to  Joseph Zorzin
May 14, 2021 12:27 pm

Uh, MSNBC? Bill Gates IS main stream media.

Tom Halla
Reply to  dk_
May 14, 2021 12:29 pm

I believe Microsoft sold their interest in MSNBC years ago.

Gordon A. Dressler
May 14, 2021 10:33 am

Regarding the first graph in the above article, the “yearly-average CO2 concentration” in Earth’s atmosphere, based Mauna Loa observatory precision measurements, is currently about 416 ppm and has been rising at a rate of 2.7 ppm/year over the last three years. Note that it varies approximately +/- 4 ppm about the annual trend line in the course of a single year.

Therefore, updating (extrapolating) the referenced graph to current observed average conditions, it is easy to see that all-but-one of the referenced models’ predictions for CO2 levels have not come close to reality . . . the single exception being the predictions of a green (1980’s) model that is otherwise not identified (it may be the Russian global climate model.) Almost all of the other models (individually or together as providing a range of predicted values of CO2 concentration) have overstated their predicted increase of CO2 concentration . . . with some of these predictions originating as recently as 30 years ago (i.e., the orange, 1990’s, models).

So, we should be worried about model predictions being made for atmospheric CO2 concentration levels in year 2100, some 80 year into the future??? Give me a break!

Gary Pearse
Reply to  Gordon A. Dressler
May 14, 2021 1:32 pm

Moreover, the main thing that drives ½ of CO2 emitted to dissolve (become sequestered) in the ocean under present average ocean water temperatures, is the partial pressure of CO2 in the atmosphere.

This is a reversible effect. That is to say that if we reduced CO2 from the atmosphere to, say 350ppm, then the oceans would respond with a net outgassing to attempt restore the partial pressure. You would need to remove double the amount of CO2 that you think you would (probably more than half comparing the relative magnitude of the massive ocean sink (?)). This is part of the reason why a year and a half lockdown had basically an undetectable sign in the Mauna Loa CO2 atmospheric measurements.

Chris Nisbet
May 14, 2021 10:48 am

Contrast this with the ‘existential threat!!’ garbage that gets rammed down our throats by our govts and traditional media.
What will it take for our governments to stop denying the truth of this?

Gregory Woods
Reply to  Chris Nisbet
May 14, 2021 10:52 am

Governments are not known for their truth-telling…

Gordon A. Dressler
Reply to  Gregory Woods
May 14, 2021 11:07 am

Spot On!

“If you tell a lie big enough and keep repeating it, people will eventually come to believe it. The lie can be maintained only for such time as the State can shield the people from the political, economic and/or military consequences of the lie. It thus becomes vitally important for the State to use all of its powers to repress dissent, for the truth is the mortal enemy of the lie, and thus by extension, the truth is the greatest enemy of the State.” — Joseph Goebbels

Reply to  Chris Nisbet
May 14, 2021 12:41 pm

What America (alarmists) see as a threat, China sees as a benefit …

May 14, 2021 10:50 am

So far the real effects of the climate change narrative have only been economic. Electricity prices skyrocketed, building codes changed for new and existing homes, taxes to support the CC agenda, business closures dues to unreliable energy, jobs shipped elsewhere along with the CO2 production, food prices rising based on unrealized threats, and more. People should be becoming aware of the true cost of climate change by now. What’s taking them so long?

Reply to  markl
May 14, 2021 12:43 pm

Promises made by propaganda (via Agenda 21) …

Rud Istvan
May 14, 2021 11:08 am

Marcel Crok very kindly provided feedback on a number of the Blowing Smoke essays that were not first posted at Climate Etc. Knows his stuff.
First I have seen SCC estimates using observational ECS. Good for McKitrick to have run the numbers—about zero with greening. Major factoid.

Curious George
May 14, 2021 11:12 am


I use the word to denote results of actual measurements, not a projection.

M Courtney
Reply to  Curious George
May 14, 2021 11:43 am

But the projection is based on actual measurements and not theoretical modelled assumptions.
Empirical is the right word.

Robert Bradley
May 14, 2021 11:54 am

What is the 6th point above?

Reply to  Robert Bradley
May 14, 2021 6:37 pm

Although the 3rd was important, I feel that the 6th point was the most important. I did not agree with the author.

Mark BLR
Reply to  DonM
May 15, 2021 4:21 am

I feel that the 6th point was the most important

The article says “McKitrick provided the answers in this slide:”, following by a slide with “bullet-points” 1 to 5 on it.

Starting the next paragraph with “These six points …” is jarring when reading the ATL article.

I agree with Robert Bradley. Which “6th point” do you have in mind here ???

Reply to  Mark BLR
May 15, 2021 1:29 pm

I was joking…. although after using up five fingers I do sometimes get confused while switching hands.

Last edited 1 month ago by DonM
James Donald Bailey
May 14, 2021 12:39 pm

This is reminiscent of the good old days when they admitted there would be hardly any difference in the resulting temperatures no matter what they do. Poor Lomberg looked at that and came up with tons of things we could do that would improve peoples lives more. And suffered for daring to suggest a different path. I am sure they have fudged the results, (claimed to correct the Science) to make the issue go away by now.

Any truth counterproductive to the narrative must be squashed. Especially if it says things could be better if you do something different than they want, or if you say things aren’t going to be anywhere near as harmful as they claim if nothing is done.

Though it is likely that McKitrick is used to having his good science ignored or vilified and having a target painted on his back by now.

Rick C
Reply to  James Donald Bailey
May 14, 2021 4:49 pm

JDB: “Poor Lomberg looked at that and came up with tons of things we could do that would improve peoples lives more.

I think Bjorn Lomberg had the crazy idea that leftist activists might actually care about the poor in third world countries. In reality they see global wealth as a zero sum game where making the poor wealthy can only happen by making the wealthy poor. The left pays lip service the the socialist ideal of redistribution of wealth – as long as it’s someone else’s wealth, not theirs.

Steve Z
May 14, 2021 1:03 pm

According to the top graph, CO2 levels rose from about 325 ppm in 1970 to about 405 ppm around 2015, or 80 ppm in 45 years. This represents an average rise rate of about 1.8 ppm per year.

Global CO2 emissions in 2019 were about 33 GT (gigatonnes). A mass balance on the atmosphere shows that if all human-emitted CO2 remained in the atmosphere, the CO2 concentration should rise about 1 ppm for every 8 GT of CO2 emitted, which should result in a rise of 4.1 ppm/yr in 2019. This means that 56% of the human-emitted CO2 (about 2.3 * 8 = 18.4 GT/yr) is removed from the atmosphere by natural processes (including photosynthesis).

If increasing CO2 concentrations in the atmosphere cause plants to grow faster, the CO2 removal rate by photosynthesis would increase. If this is a linear response to concentration, then the CO2 removal rate would catch up to the emission rate (33 GT/yr) when the CO2 concentration reached 410 * 33 / 18.4 = 735 ppm, if human CO2 emissions remained constant at 33 GT/yr. Once the removal rate catches up to the emission rate, the CO2 concentration in the atmosphere should stabilize. But think of how much food the Earth could produce at that concentration!

The “social cost of [emitting] carbon [dioxide}” may very well be negative!

The IPCC keeps talking about a climate sensitivity to a doubling of CO2 concentrations (which is usually over-estimated). But taking into account an increasing CO2 removal rate, we may never get to double the present concentration!

Bravo to Prof. McKitrick for an excellent article!

Rud Istvan
Reply to  Steve Z
May 14, 2021 1:59 pm

Ocean studies in the north Atlantic have shown greening there, also. For example, coccolithophores up over 10 x in numerical abundance over past three decades. And those little critters permanently sequester carbon in their exoskeletons as calcium carbonate. They formed the white cliffs of Dover.

May 14, 2021 1:14 pm

So the bottom line is that all of the collective and costly efforts of OECD nations to strive for short term net zero CO2 emissions essentially will not offset the continuing increase in non-OECD nations, even just that from China, say nothing about the sum inclusive of India. The essentially “equity-driven concept (you must remove your privileged, former and current contributions so that we can raise our productivity and living standards) inclusive of sequestration of CO2 from the atmosphere in technologically advanced nations, is fraught with incredible economic consequences. And in the end, the projected impact of removing CO2 emissions is really still highly uncertain, with little accurately modeled in terms of cloud effects, particulates, and upper atmosphere deposition of sulfur, water vapor, and CO2.

Last edited 1 month ago by fred101
May 14, 2021 1:58 pm

Can someone explain how to get the one figure, with attribution to Hausfather 2019, fro the actual Hausfather 2019 article?

Chris Hanley
May 14, 2021 2:36 pm

“… In the 2017 paper they used empirically constrained estimates for climate sensitivity (adapted from a paper by Nic Lewis and Judith Curry) instead of much higher model based estimates …”.

As I understand it those empirically-based estimates of sensitivity assume all the observed warming was due to the increasing CO2 concentration.
There being no planet Earth ‘B’ for comparison I guess that is the only possible method.

michael hart
May 14, 2021 3:33 pm

I don’t see an actual link to a presentation with Ross himself, but I’ve found a talk he gave on 12th May. It’s probably the same thing, though I don’t know for sure, not having watched it yet.

Robert A. Taylor
Reply to  michael hart
May 14, 2021 4:51 pm

Thanks for the link. I intend to follow McKitrick from now on.

Rory Forbes
Reply to  Robert A. Taylor
May 14, 2021 5:36 pm

It was McKitrick’s collaboration with Steven McIntyre that falsified Mann’s “hockey stick” nonsense, nearly two decades ago. Canada used to be at the cutting edge of AGW falsification.

Check out McIntyre’s

Robert A. Taylor
May 14, 2021 4:59 pm

Excellent! Michael Hart gives a link to the actual presentation. Highly recommended.

Paul Johnson
May 14, 2021 9:36 pm

The IPCC guesses that under the most pessimistic emissions scenario (RCP8.5) with no mitigation, U.S. GDP in the year 2100 might be impaired by 10.5%. This sounds daunting, but it means that at normal growth rates, levels of productivity and wealth expected in 2100 could be delayed until maybe 2103 or 2104.
In this worst-worst case, our great-great-great grandchildren would suffer such economic hardship that they would have to defer their vacation to Lunar Disney for several years. Oh, the horror!

Mark BLR
May 15, 2021 4:05 am

As you can see the real CO2 concentration in the atmosphere ‘hugs’ the bottom end of the forecast range (after decades of forecasts). McKitrick added this will again be the case in the upcoming AR6 report.

The University of Melbourne has an excellent webpage allowing you to download the “Greenhouse Gas Concentrations” used by the CMIP6 models (“Historical Data” from 1AD to 2014, per-SSP from 2015 to 2500).

The following link takes you directly to the “Carbon dioxide, Download data files, SSP5-8.5 pathway” configuration :!/ghg?mode=downloads&scenarioid=9

Scrolling down to the “Historical –> Yearly –> CSV” (once) and cycling through the various “Future Scenario: XXX –> Yearly –> CSV” options allowed me to generate the attached graph last autumn.
NB : The “MLO-prime” line plots the Mauna Loa “annual averages” from September to August. This best matches the CMIP6 “Historical Data” numbers from 1958 to 2014.

Rather than “hugging the bottom end of the [CMIP6 / AR6] forecast range”, actual atmospheric CO2 abundances are already below all of the CMIP6 “pathways” (which effectively start in 2015), but are still roughly in the middle of the CMIP5 range (a widening “fan” since 2006).

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