What’s the worst case? Emissions/concentration scenarios

Reposted from Climate Etc.

Posted on March 28, 2019 by curryja |

by Judith Curry

Is the RCP8.5 scenario plausible?

This post is Part II in the possibility series (for an explanation of the possibilistic approach, see previous post link).  This paper also follows up on a recent series of posts about RCP8.5 [link].

3. Scenarios of emissions/concentration

Most worst-case climate outcomes are associated with climate model simulations that are driven by the RCP8.5 representative concentration pathway (or equivalent scenarios in terms of radiative forcing). No attempt has been made to assign probabilities or likelihoods to the various emissions/concentration pathways (e.g. van Vuuren et al. 2011), based on the argument that the pathways are related to future policy decisions and technological possibilities that are considered to be currently unknown.

The RCP8.5 scenario was designed to be a baseline scenario that assumes no greenhouse gas mitigation and no impacts of climate change on society. This scenario family targets a radiative forcing of 8.5 W m-2 from anthropogenic drivers by 2100, which is nominally associated with an atmospheric CO2 concentration of 936 pm (Riahi et al. 2007). Since the scenario outcome is already specified (8.5 W m-2); the salient issue is whether plausible storylines can be formulated to produce the specified outcome associated with RCP8.5.

A number of different pathways can be formulated to reach RCP8.5, using different combinations of economic, technological, demographic, policy, and institutional futures. These scenarios generally include very high population growth, very high energy intensity of the economy, low technology development, and a very high level of coal in the energy mix. Van Vuuren et al. (2011) report that RCP8.5 leads to a forcing level near the 90th percentile for the baseline scenarios, but a literature review at that time was still able to identify around 40 storylines with a similar forcing level.

Storylines for the RCP8.5 scenario and its equivalents have been revised with time as our background knowledge changes. To account for lower estimates of future world population growth and much lower outlooks for emissions of non-CO2 gases, more CO2 must be released to the atmosphere to reach 8.5 W m-2 by 2100 (Riahi et al., 2017). For the forthcoming IPCC AR6, the comparable SSP5-8.5 scenario is associated with an atmospheric CO2 concentration of almost 1100 ppm by 2100 (O’Neill et al. 2016), which is a substantial increase relative to the 936 ppm reported by Riahi et al. (2007).

As summarized by O’Neill et al. (2016) and Kriegler et al. (2017), the SSP5-8.5 baseline scenarios exhibit rapid re-carbonization, with very high levels of fossil fuel use (particularly coal). The plausibility of the RCP8.5-SSP5 family of scenarios is increasingly being questioned. Ritchie and Dowlatabadi (2018) challenge the bullish expectations for coal in the SSP5-8.5 scenarios, which are counter to recent global energy outlooks. They argue that the ‘return to coal’ scenarios exceed today’s knowledge of conventional reserves. Wang et al. (2017) has also argued against the plausibility of the existence of extensive reserves of coal and other easily-recoverable fossil fuels to support such a scenario.

Most importantly, Riahi et al. (2017) found only one single baseline scenario of the full set (SSP5) reaches radiative forcing levels as high as the one from RCP8.5 (compared with 40 cited by van Vuuren et al. 2011). This finding suggests that 8.5 W/m2 can only emerge under a very narrow range of circumstances. Ritchie and Dowlatabadi (2018) notes that further research is needed to determine if plausible high emission reference cases consistent with RCP8.5 could be developed with storylines that do not lead to re-carbonization.

Given the socio-economic nature of most of the assumptions entering into the SSP-RCP storylines, it is difficult to argue that the SSP5-RCP8.5 scenarios are impossible. However, numerous issues have been raised about the plausibility of this scenario family. Given the implausibility of re-carbonization scenarios, current fertility (e.g. Samir and Lutz, 2014) and technology trends, as well as constraints on conventional coal reserves, a categorization of RCP8.5 as ‘borderline impossible’ is justified based on our current background knowledge.

Based on this evidence, Ritchie and Dowlatabadi (2017) conclude that RCP8.5 should not be used as a benchmark for future scientific research or policy studies. Nevertheless, the RCP8.5 family of scenarios continues to be widely used, and features prominently in climate change assessments (e.g. CSSR, 2017).

JC note:  next installment is climate sensitivity

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Joel O'Bryan
March 31, 2019 10:40 am

“the comparable SSP5-8.5 scenario is associated with an atmospheric CO2 concentration of almost 1100 ppm by 2100….”

How can people who call themselves “scientists” employ such obvious falsehoods in their work? Inventing impossibilities and using them in scenario — Hollywood does that all the time their movie plots to sell titillation and fear in a scifi movie.. Really. So when the rapid extraction of non-existent coal at a rate non-conceivable in the real world is the basis of a scenario, it is pure science fiction. Something straight out of “The Day After Tomorrow.”

But I suppose I answered my own question. That is, they aren’t scientists. They may be a lot of other things like snake oil sellers, charlatans, rentseekers, and pathological liars, but they aren’t scientists. That much is certain.

Joel O'Bryan
Reply to  Joel O'Bryan
March 31, 2019 11:47 am

The SSP5-8.5 scenario:
If we use a very aggressive assumption of logarithmic growth of CO2 concentrations, then to get to 1,092 ppm by 2100 (81 years and 682 ppm from today) requires a growth factor of k= 0.0121.

The math with k= 0.0121 :
C = Co x e^(kt) —> 410ppm x e^(0.0121*81) = 1,092 ppm in 81 years.

Which means we hit 560 ppm (2x pre-industrial of 280 ppm) in 2047, a mere 28.5 years from now. And then 820ppm (2x from today’s 410) in 2076 .

Further, between today and 2025 (next 6 years), the MLO-observed CO2 annual rate would have to double to 5 ppm/year over the current ~2.5 ppm/yr today to achieve a logarithmic growth rate to 440 ppm by 2025 (6 years). In the final 5 years of the century (2095-2099) the annual CO2 growth would have to exceed 12.7 ppm/yr to hit 1,092 ppm by 2100, or more than five times higher than today.

So each year going forward from 2019 (today) that that annual CO2 growth remains well below 3 ppm ( < the 5 ppm/yr over the next 5) it makes the final year's growth in 2099 exceed 12.8 ppm/yr.
Conclusion: The 1,092 ppm by 2100 is an already an impossible scenario. This is will be invalidated before the next AR6 even comes out in 2 years.

But hey, when did "impossible" ever stop the pathological liar climate alarmists?
And besides, we're supposed all be dead by 2030, so party on like it's 1999 every year.

Reply to  Joel O'Bryan
March 31, 2019 1:13 pm

I think it’s more like “party like it’s 1984”.

Gary Pearse
Reply to  F.LEGHORN
March 31, 2019 5:48 pm

Ordinarily, in a science with real conscientiously collected ‘chips-fall-where-they- may quality data and models that aren’t tuned to find human caused catastrophic ruination of the planet and its systems and inhabitants as ordered by marxiste Maurice Strong, this exercise may have merit. I think Judith is exploring the ridiculous and will be providing food for starving catastrophist sharks. What is “probable” as defined by the UNFCC is bad enough. Good Lord, don’t whet their apetites legitimizing for consideration what is ‘possible’ framed in the risk management world, especially using ersatz data.

We already know, and no one among the climato synod even bothers to dispute it. They even
say in any case it’s the tight thing to do to shut down civilization.

Izaak Walton
Reply to  Joel O'Bryan
March 31, 2019 2:01 pm

Your required growth rate of 0.0121 is less than half what the actual growth rate of CO2 emissions
were in 2018. Last year as Larry Hamlin pointed out in a recent blog post CO2 emissions grew by
2.7%. Fuelled by growth of coal use in China. So if China is “further accelerating” its coal use surely
RC8.5 is looking more plausible.

I also note that one of the main reasons why Dr. Curry appears to think RCP 8.5 is impossible is that there is not that much coal left. So she would appear to be subscribing to “peak coal” which is not something I have heard expressed on this blog before.

Joel O’Bryan
Reply to  Izaak Walton
March 31, 2019 5:45 pm

You are confusing emissions with CO2 concentration. I said nothing about emissions.
I’m ficused on CO2 annual growth rate which for the last 20 years has averaged around 2.1 ppm, but is clearly influenced by ENSO cycles.

Annual mean CO2 growth rate and emissions are clearly not linked on an annual emissions basis. They are definitely not 1:1 as emissions fell world-wide in 2009-2010 over 2007-2008 emissions due a global growth slowdown. The MLO records more losely with the + global temp anomaly and ENSO La Ninas and ElNinos. There is also a likely under reprting of China’s and India’s emissions to reduce diplomatic pressure.

For climate models, what matters is annual CO2 growth rate and the CO2 concentration for LWIR forcing in the AOGCMs. CO2 concentration,not emissions, matter because an additional gigaton co2 emitted in 2020 matters far more than an additional gigaton in 2050, not because the logarithmic effect of forcing, but because the biologic sinks will have higher kinetics then if greening continues.

Izaak Walton
Reply to  Joel O’Bryan
March 31, 2019 6:57 pm

An annual growth rate of 2.7% in emissions such as the world managed in 2018
will get the CO2 levels to over 1000 ppm by close to the end of 2100. As such we
are on track for RCP 8.5 or if not just below it.

Joel O'Bryan
Reply to  Joel O’Bryan
March 31, 2019 8:41 pm


I stand by my analysis that the actual MLO annual growth rate does not support that conclusion.

For CO2 concentration to even start to approach those levels by the end of the century, [CO2] will need to be at ~440 ppm by end 2025 or very near (+/- 2). It’s currently at 412 (end March 2019) and will fall to ~407-408 ppm by September, then climb to back around 411 by year’s end. So then MLO [CO2] will have 6 years to reach 440 (climb by 29 ppm which is about a ~5ppm/yr growth rate on average).

So yes we are in a period of rapid Chinese, India, PNG, Malaysia, and Indonesia coal power plant build out for the next 10 years. So if you are right, then 440 (+/-2) ppm by end-2025 should easily happen.

Care to wager?
I say MLO CO2 will be not greater than 432 ppm by end-2025. CO2 Between 432 to 438 ppm would be a draw as either could be correct within that overlap.

Izaak Walton
Reply to  Joel O’Bryan
March 31, 2019 9:02 pm

Simple maths says that if CO2 emissions continue to grow at 2.7% for the next
80 years the concentration at the end of that time will be 996 ppm. So again we
are currently on track to follow RCP 8.5. Following that same growth rate puts the
level in 2025 at 425ppm which is below your claimed figure of 440.

More fundamentally most people here think that fossil fuels are cheap, abundant and
we should be burning more of them in order to continue to raise our standard of living and bring billions of people out of poverty. But also somehow RCP 8.5 is a fantasy for
reasons that are never clearly expressed. Dr. Curry is claiming that there aren’t enough fossil fuel reserves for RCP 8.5 to be plausible — which means that she is predicting that the world will be running on renewables by the end of the century. But no-one here seems to be claiming that that is impossible.

R Shearer
Reply to  Joel O’Bryan
March 31, 2019 9:18 pm

Izaak, renewables can’t do it, but nuclear energy can be scaled. And yes, RCP 8.5 is ridiculous.

Izaak Walton
Reply to  Joel O’Bryan
March 31, 2019 9:21 pm

R. Shearer,
You claim RCP 8.5 is ridiculous. Can you explain why? Are you saying that there
isn’t enough fossil fuels for it to be valid or is it that humanity will choose not to
burn them?

Joel O’Bryan
Reply to  Joel O’Bryan
April 1, 2019 12:04 am

Izaak, again you cannot seem to understand that anthropogenic CO2 emissions are not the equivalent of CO2 growth rate in the MLO CO2 record. There is ample observational evidence for this.
Average annual CO2 growth from the MLO record is better explained by the general global warming trend out of the LIA, volcanic aerosol coolings, and ENSO cycles.

Thus emissions growth rate is not proportional CO2 growth rate. That means Actual atmospheric levels of CO2 are only loosely coupled to emissions. We don’t know why. NASA’s OCO-2 satellite was supposed to help answer that question.

Until you understand that there is a disconnect, it is hopeless to talk about emissions growth and future values of CO2 concentrations.

Izaak Walton
Reply to  Joel O’Bryan
April 1, 2019 1:54 am

The CO2 growth rate is less than the human emission rate. It is actually about 50% of the
anthropogenic emission rate. Therefore humans are responsible for about 200% of the growth rate of CO2 in the atmosphere. Natural sinks are responsible for absorbing about 50% of human emissions and this rate is declining as we saturate them. Claiming that the growth in atmospheric CO2 levels are not related to human emissions is absurd. Isotopic analysis for example shows clearly that the extra CO2 is coming from burning fossil fuels.

Joel O’Bryan
Reply to  Joel O’Bryan
April 1, 2019 6:35 am


Have you ever seen a GCM reconstruction of the atmosphereic CO2 “record” using the temperature records? And then from the “reconstructed” CO2 output then a model reconstruction of what the presumed anthropogenic emissions would have been using the relationship as you understand it? It is quite an enlightening analysis.
A reconstructed atmospheric CO2 from instrumental temperatures looks nothing like the MLO instrumental record. And then it follows the climate model reconstructed emissions look nothing like the best estimates of emissions from oil, coal and natural gas utlization.
Major paradigm disconnects.

And the seasonal uptake of CO2 in the NH growing season, May-September, is a clear indication that sinks are far from saturated. The kinetics of the sinks (uptake) are increasing with the increasing CO2 emissions from humans. Sinks with diminishing uptake would show the opposite behavior than observed.

Reply to  Joel O’Bryan
April 1, 2019 8:21 am

“An annual growth rate of 2.7% in emissions such as the world managed in 2018
will get the CO2 levels to over 1000 ppm by close to the end of 2100.”

So by the same analysis, since my 60+ year-old body can run a 100 meters in under 25 seconds, I can run 1 kilometer in under 250 seconds. Right?

Reply to  Joel O’Bryan
April 1, 2019 8:33 am

“Simple maths says that if CO2 emissions continue to grow at 2.7% for the next
80 years the concentration at the end of that time will be 996 ppm. So again we
are currently on track to follow RCP 8.5.”

Simple maths yield simple answers. Not correct answers. We are not now, and never have been “on track to follow RCP 8.5.”

RCP 8.5 would not only require China and the U.S. to burn vastly more coal in 2100 than they did in 2018, but it would require that they *continuously* increase from the 2018 levels to the much-higher 2100 levels.

RCP 8.5 was known to be a joke (to anyone who has seriously studied likely future energy scenarios) even at the time it was published. Its purpose was to allow “scientists” to use “science” to scare people. It has accomplished its purpose.

Reply to  Izaak Walton
April 1, 2019 8:36 am

” Therefore humans are responsible for about 200% of the growth rate of CO2 in the atmosphere.”

If you choose to ignore soils which contribute six times as much CO2 to the atmosphere as humans and respond to rising temperatures with further contribution.

“Isotopic analysis for example shows clearly that the extra CO2 is coming from burning fossil fuels.”

Isotopic evidence shows increased atmospheric CO2 is not coming from volcanoes. Human combustion and soil respiration are isotopically indistinguishable.

comment image

Soil respiration temperature response is pretty linear at about 20% increase per degree C. A 20% increase in soil respiration in response to the ~1 degree warming since 1850 would yield 12 Gt annually. About current human production. Humans are therefore responsible for 50% of the atmospheric increase.

Jean Parisot
Reply to  Joel O'Bryan
March 31, 2019 6:10 pm

Damn, I want us to get to 1200ppm. Looks like it will be hard to do in my life time.

Reply to  Joel O'Bryan
March 31, 2019 12:00 pm

In many cases science has been cheapened by the plethora of diploma mills and the concomitant glut of diploma holders who populate the false economies created and sustained by virtually unlimited tax monies. Let that tit go dry, so to speak, and much of this bullsh!t would cease. A lot of .gov/.edu science these days is just busy work to justify “earned” privilege and facilitate the interests of those funding it.

William Astley
Reply to  Joel O'Bryan
March 31, 2019 12:44 pm

Liars is perhaps too strong a word, not accurate.

What is happening is confirmation bias and institutional failure to stand up to enormous, constant political and academic pressure to push and support CAGW.

The cult of CAGW’s general circulation models and their Bern model of CO2 sinks and resident times have both been falsified by observations.

The logical, unemotional scientific response to falsification (Field in question is in crisis) is to form a new hypothesis rather than:

1) Calling those who point out the scientific falsification deniers
2) Firing editors who publish papers and fire scientists who write papers that disprove CAGW/AGW
3) Doubling down on scary predictions and modifying the historic temperature record to push CAGW

This is an OK summary of the observations/issues that disprove CAGW and AGW.


Joel O'Bryan
Reply to  William Astley
March 31, 2019 12:57 pm

Operational definition of a Liar = someone:
1) purposefully making/issuing a deception/falsehood with
2) an intent to deceive another.

The IPCC AR6 WG1 authors will satisfy both criteria with the use of wholly unrealistic emission scenarios to achieve that level of CO2 forcing and placing that in their report where it will be widely consumed.
Basically they are intentionally turning their science into science fiction to dupe an ignorant public and useful idiot press reporters. They need to be called what they are.

William Astley
Reply to  Joel O'Bryan
March 31, 2019 5:08 pm

When groups lie, it is different.

CAGW the idea is powerful. Taught by decree in schools.

They are following their institutional paradigm.

Think of the stigma, the ignorant animosity behind the label ‘Denier’. Universities have fired prominent, scientists for publishing papers that challenge, disprove CAGW/AGW.

It likely is not possible to get a job, to get tenure, if one questions or worst attempts to get papers publish that challenge CAGW.

The IPCC scientists were/are chosen based on their commitment to the cause. There is government money, NGO money, and political pressure to push the paradigm.

March 31, 2019 11:08 am

In the long term cooling is the major concern. In the even longer term CO2 starvation is the greater threat.

So what are we doing now?

Paul Penrose
Reply to  kim
April 1, 2019 11:15 am

Can’t make this point often enough. For this interglacial we are already past the peak warmth (which didn’t cause the end of the world, btw), it’s all downhill from here. I know it’s hard for a species made up of individuals that live less than 100 years to think about time-scales of hundreds or thousands of years, but that’s the only way to understand the longer climate trends. Natural forces, very power forces, have already begun to push this planet back into the ice age that was interrupted by the current interglacial period. It is doubtful that we will be able to halt that slide even if we have another 1000 years to try. The best case is a bit of a delay by forcing a little warming now. Hopefully that will give us the time we need to prepare for the return of the ice.

March 31, 2019 11:15 am

We’re not likely to quadruple baseline CO2(two doublings) before nuclear energy is more cost effective even than coal.

At a low sensitivity, which is likely, anthropogenic warming will still be net beneficial.

There will come a time, when even kim doesn’t know but probably quite a ways off, when humanity will be attempting to supplement CO2 into the atmosphere, for its greening effect even more than its warming effect.

The action of the sun and the biome sequesters CO2 almost irreversibly. Fortunately humanity will probably eventually be able to reverse that, more than our feeble effort with hydrocarbons. It will be necessary to keep photosynthesis, and thus the basis of life, ongoing.

‘Tis absurd to fear,
Chlorophyll and CO2:

Bryan A
Reply to  kim
March 31, 2019 11:35 am

Humanity is already supplementing CO2 into the atmosphere, of greenhouses, not for its negligible warming effect but for it’s atmospheric fertilization effect. Farmers already know about the effect of increased CO2 levels on overall biomass production

Reply to  Bryan A
March 31, 2019 11:56 am

Estimate how many hungry bellies Anthro CO2 has already filled. Could be billions, and will be cumulatively.

Does hoi polloi, bellies well filled know this? You make me laugh.

Reply to  kim
March 31, 2019 12:12 pm

“We’re not likely to quadruple baseline CO2(two doublings) before nuclear energy is more cost effective even than coal.”

In a way, this encapsulates the problem. On one hand we have the Debbie Downers who live in model world (and who are probably incompetent as h3ll), who are stuck on stupid in linear-think licking their bosses’/pay masters’ @ss, and on the other hand we have human ingenuity that says, “You ain’t seen nothin’ yet”.

michael hart
Reply to  kim
March 31, 2019 2:42 pm

I would bet against us even reaching 600 ppm. The growth rate of carbon sinks is hardly stretching its legs yet. Most of the increase is probably due to CO2 NOT being a well mixed gas.

Greg Freemyer
Reply to  michael hart
March 31, 2019 7:19 pm

450 PPM. Peak is my guess, and that may be high.

Agriculture need massive amounts re of carbon and they have figured out how to get it out of the climate. We could have hit peak CO2 PPM by 2050 with no problem.

Rich Davis
Reply to  kim
March 31, 2019 3:02 pm

You are so right about this, kim. Each successive warm period has been cooler than the previous from the Holocene optimum through the Minoan, Roman, Medieval, and Modern warm periods. Eventually our climate will fall into a glaciation period again. It’s still many centuries off, most likely. It may be only 20,000 years, though? We won’t have significant amounts of fossil fuel left by then to survive that change. Even the next Little Ice Age is likely to strike hard against modern civilization.

In the next five to ten years it will become clear from a cooling trend, that the claims are wrong that there can be no ice age due to our fossil fuel burning, that our influence is overwhelming natural effects. At that point, let’s hope that we wise up and focus on next generation nuclear energy. Otherwise, eventually there must be mass starvation, maybe a lot sooner than anyone imagines. Luckily we have a couple of centuries worth of fossil fuels left to bridge the gap to nuclear.

There must be no serious doubt that CO2 depletion throughout the Phanerozoic Age is pointing toward a very distant future likely during a glaciation where atmospheric CO2 concentration falls below about 50 ppm, leading to an end of photosynthesis and the final extinction of animal life that depends on plants or other plant-eating animals for food. Most of the earth’s carbon will have been sequestered in carbonate rock that is very energy-intensive to convert back to metal oxides and CO2. Pretty much every multi-cellular lifeform lacking the intelligence to survive in artificial environments will go extinct, unless preserved by intelligent life.

Our distant offspring are going to need incredible amounts of energy to liberate sufficient quantities of CO2 from carbonates such as limestone, in order to continue photosynthesis. In the midst of a glaciation, most of the CO2 produced at great cost would be sucked up by the cooling oceans if it were simply released to the atmosphere. It will likely be a case of needing to build massive greenhouse operations in the tropics where the CO2 produced is not allowed into the open air. Will there be cheap abundant fusion power a million years from now to facilitate that? I wouldn’t bet on it. But after a million more years of government grants, they will still be predicting that it is just another 30 years away, no doubt.

In those dystopian days of the very remote distant future, if there is still any record of our late 20th and early 21st century mania, the idea that CO2 is harmful to life on earth will be a bitter irony.

Reply to  Rich Davis
March 31, 2019 3:20 pm

Um.. What happens to carbonate rocks when subducted into the mantle?

Rich Davis
Reply to  pochas94
March 31, 2019 3:30 pm

The CO2 is liberated of course. But eventually the deposition of carbonates exceeds the amount subducted and this only gets worse as the earth is cooling and tectonic action slows, right? Perhaps many millions of years rather than “a million years”, but I was just affirming Kim’s comment by addressing the very long-term scenario.

Rich Davis
Reply to  Rich Davis
March 31, 2019 3:40 pm

So those long-long-term conjectures are kind of pointless of course. Many other possibilities I’m sure. The liquid iron core solidifies and we lose our magnetic field shielding us from deadly radiation, which would likely kill most all life on the surface, for example. Or we have a sterilizing massive asteroid strike that incinerates the surface and blots out the sun for many years, for another example. Nothing that is going to happen next Tuesday.

The next Little Ice Age, on the other hand, is possibly well within our lifetimes.

Reply to  Rich Davis
March 31, 2019 6:50 pm

By then we’ll be on intragalactic ships orbiting out new home(s) and doing exercises to adjust to the gravity of the new home planet and defend against the new predators and diseases and trying to negotiate with the inhabitants. Don’t worry so much.

Rich Davis
Reply to  Rich Davis
April 1, 2019 5:03 pm

The only thing I “worry” about is that we are on course to waste trillions of dollars on “mitigating” a benefit and failing to prepare for a true problem (global cooling). The next Little Ice Age is a very real possibility within the next few decades.

The point of the discussion was that CO2 is a good thing. Without it, there would be an end of life on earth.

March 31, 2019 12:29 pm

Scott Adams seems PERSUADED by the idea that the Russian INM-CM5 model is the only one that has correctly predicted the past.
That is a fairly simple concept, easily grasped by non-scientists.
It would be useful to share John Christy’s figure (4th chart in https://cei.org/blog/national-climate-assessment-still-needs-reset) far and wide.
Although, that figure is for INM-CM4, and if someone can find a similar figure of INM-CM5, that would be better.

Bruce Cobb
March 31, 2019 12:38 pm

By coincidence, I’ve been concerned about the worst case scenario for a space alien attack – RSAAP4.0 (Representative Space Alien Attack Pathway 4), and how likely it is. In Scenario 4, which is based on business as usual and where we do nothing at all to prepare, all human life is obliterated. The likelihood is based on a complex set of equations based on the known galaxies and the probablity of there being habitable planets, how far along the inhabitants may have evolved, and how far away they are. If we do nothing, then space alien destruction (SAD) of some sort is pretty much certain. Further study is necessary of course.

Joel O'Bryan
Reply to  Bruce Cobb
March 31, 2019 12:48 pm

where we do nothing at all to prepare, all human life is obliterated…”

Well, they better hurry up and kick their warp drives to warp-factor 9 cuz’ we’re all supposed to be krispy kritters in under 12 years.

Reply to  Bruce Cobb
March 31, 2019 1:01 pm

As long as they come to serve man, there’s no problem.

Oh wait… derp!

Rich Davis
Reply to  icisil
March 31, 2019 3:14 pm

Make that to serve Mann, and we’re ok.

J Mac
Reply to  Rich Davis
March 31, 2019 4:49 pm

Aliens like butterball turkeys? Who knew….

March 31, 2019 2:01 pm

All of the scenarios fail to take into count the fact that as CO2 increases, the biosphere ramps up and absorbs more of it as well.

Reply to  MarkW
March 31, 2019 2:40 pm

Yes, that is a very interesting question there, one for which I wish an answer. Something is swallowing an ever increasing amount of CO2 released so that the amount raised each year is only a constant.

Greg Freemyer
Reply to  kim
March 31, 2019 7:39 pm

Kim, regenerative agriculture use arbuscular mycorrhizal fungus (AMF) to sequester 5-20 tonnes CO2e / hectare / year in the soil. (2-8 tonnes/acre).

Plowing farmland kills of the AMF.

21% of US cropland in 2017 was using continuous no-till land management to keep from killing off the AMF. That’s 60 million acres.

Assume 2 tonnes CO2e / acre for that 60 million acres. That’s 0.12 GT CO2e for just the US.

Global found be 10x that, or 1.2 GT CO2e. That’s for cropland.

Ranchers are using adaptive multi-paddock (AMP) grazing to do similar. A ranch in Australia just got awarded certified carbon sequestration credits for 11.2 CO2e /hectare. AMP is fairly common now globally. Could be another 1.2 GT CO2e. That range land.


There’s a billion hectares (2.5 billion acres) of “loess” globally. That’s former crop/range land which had all the carbon depleted by poor agriculture practices. At least a couple hundred million acres of that is under restoration. Maybe 0.6 GT CO2e / year headed into that soil.

Thus 3 GT CO2e / year going into soil carbon. Could that be your missing CO2?

Greg Cavanagh
Reply to  kim
March 31, 2019 10:22 pm

My conjecture in response to such evidence is that the oceans and the slow warming of them, is solely responsible for the increase in atmospheric CO2. All other sources and sinks are irrelevant by comparison. More research needed, of course :).

Greg Freemyer
Reply to  Greg Cavanagh
April 1, 2019 4:20 am


Use woodfortrees to study the 1990 to 1997. For whatever reason the world’s ocean surface waters stopped warming for that time.

But then look at CO2 at the same period. It did slow its accumulation rate, but it definitely did not fall to zero.

Just looking at it visually it looks like the 1/3rd of CO2 accumulation can be attributed to the warming ocean, but the other 2/3rds still needs an attribution.

There’s only 3 logical choices: fossil fuel combustion, cement, agriculture

Agriculture is a huge and typically ignored source. Healthy, pristine US prairie contained on the order of 250 tonnes of carbon per acre. Call it 200 million acres (a guess on my part), or 50 GT of carbon sequestered there. In round numbers, that’s 200 GT of CO2e. That’s just the US.
Even ignoring the Sahara desert, Africa has on the order of half a billion acres of degraded (carbon depleted) soil. Now we are at 700 GT of CO2e.
comment image

Add on Austrailia and Asia and you can easily get over 1000 GT CO2e or 250 GT carbon. About half of that carbon is no longer in the soil due to farming. Call it 125 GT carbon.

The difference between 290 PPM CO2 and 410 PPM CO2 is about 250 GT of embedded carbon. Did half of it come from the soil?

Greg Cavanagh
Reply to  Greg Freemyer
April 1, 2019 5:19 pm

Life is Carbon based, and there is much life in the world and in the waters. Also the shellfish alive and dead represent a huge Carbon sink. Then there are volcanoes, and whatever has been subducted under the continental shelves.

You’re point about water temperature as a single metric doesn’t convince me, because the cold water around the poles absorb the CO2 straight out of the air, and the warm waters around the equators release the CO2 back into the atmosphere. Then there is the deep ocean which sits around 4C for centuries on end.

There is something releasing vast amounts of CO2 into the air. We’re just not 100% sure what it is. There are so many possibilities.

March 31, 2019 2:17 pm

The worst case is that climate continues to evolve as it has for thousands, nay, millions of years, while life continues to thrive.

Reply to  pochas94
March 31, 2019 2:37 pm

Hey, we(well sorta we) survived a six mile wide meteor. Even birds survived and they look fragile.

March 31, 2019 2:49 pm

Only when politicians stop worrying about the Media and academies
obsession with Climate Change, and cut off the taxpayers money, will this
nonsense cease.

But as they say, they the Politicians “Represent us” ? so they must respond.

Of course we know that its also about keeping their well paid jobs too.

And lets not forget the “Wizard” behind the Green curtain, pulling the levers,, like the late Maurice Strong did. . They all have a new Political system just waiting to be tried out on us.


March 31, 2019 3:20 pm

The difference between AGW alarmists and AGW luke-warmers is that one believes that increasing ghg emissions will be catastrophic and the other believes it is a small problem but not a serious problem and may have some benefits.

The similarity between them is that they are both wrong.

CO2 does not control the weather or climate in general. To say so is junk science, cargo cult science, voodoo science, group think, promotion of a Marxist agenda, political opportunism, socialist opportunism, financial opportunism, plain bonkers …. Take your pick.

As HotScot repeatedly points out there is no empirical or observational evidence to support the AGW hypothesis outside the climate models.

Yet governments throughout the world (except the USA) include decarbonisation of the economy in their “things to do” list.

Unlike most climate sceptics who contribute to and those who comment on this website I do not believe we are winning the argument or that the climate fraud will end any time soon. Not while the IPCC exist or the cronies that contribute to it.

Paul Rossiter
Reply to  leitmotif
March 31, 2019 8:29 pm

I couldn’t agree more.

With so much vested interest in propping up the AGW-climate catastrophe mantra, credible scientific argument is almost totally impotent. This is evident in the continuing (or even growing?) bias of the popular media and the race to the carbon bottom of governments more worried about the ballot box than actually making decisions in the true interest of the people. It is reinforced by a well-oiled education system that preaches the AGW religion (from primary through university) and popular moral beacons such as David Attenborough who rely on corrupt organizations like the BBC for their ongoing funding. it is further reinforced by all the government funded “research” institutions and agencies with their snouts well and truly in the AGW funding trough. I won’t bother to go on about the globalist government agenda or socialist dream etc. since anybody on this site will already be familiar with all the arguments.

However, I fear that us agreeing on these sites about the real data or lamenting the magnitude of the AGW fraud has had little real impact outside the immediate readership. That is in no way intended as a criticism of WUWT or any of the other “climate realist” sites which I find absolutely invaluable as a source of information and discussion, nor of the many champions of climate realism who selflessly devote enormous time and effort in trying to set the public record straight, it is simply a statement that at the moment we are completely outgunned and at best not much more than a mild irritant.

So as far as I can see, the battle is lost and the insanity will continue unless something of monumental significance occurs to reverse the trend. This might include a protracted period of global cooling such that propping up the CO2-AGW mantra finally becomes untenable, no matter what spin the vested interests try to put on it. Unfortunately, by this time the enormous resources that could otherwise have been devoted to addressing real problems like disease and poverty will have been wasted on making a few people rich, preening egos and pushing political agendas. I regard that as losing the war.

The only other hope I can see on the horizon of sufficient importance is Trump’s committee (PCCS) to review the validity of the climate assessments. Given its likely membership there is reason to believe that the real science will be given a fair hearing (for a welcome change!), though any outcome is likely to be tainted by the swamp that is currently American politics and denigrated as “biased” by all the vested interests in the aptly named “Climate Industrial Complex”.

Maybe there is also the chance of push back from a populace, like the French Yellow Vests, who finally start objecting to unjustified cost increases driven by a CO2 lunacy.

I support Edmund Burke’s view that “The only thing necessary for the triumph of evil is that good men do nothing” and so we all need to keep trying to expose the AGW lie, but gee I wish that we could get some heavier artillery to start have greater impact.

Jerry Palmer
March 31, 2019 5:18 pm

Intellectually Penurious Charlatan Collective?

March 31, 2019 9:56 pm

China is secretly building much more coal power plants, satellite images have shown: https://endcoal.org/wp-content/uploads/2019/03/BoomAndBust_2019_r6.pdf

Germany, the UK etc. should be furious

Taylor Pohlman
April 1, 2019 4:45 am

This is an opportunity for Happer and his panel to contribute. The US should lead the way in banning any policy/projection for government decision-making that uses RCP8.5. That would not only spike the worst excesses of the NCA, it would call attention to how all the scare tactics were enabled in the first place.

April 1, 2019 8:59 am

You guys are just wasting your own time. The situation is so simple its laughable. The fact is that radiated energy can penetrate the surface of water but physical heat can not.Physical heat is blocked by surface tension. AGW does not exist. Get a bucket of water and a heat gun and try heating the water.

Paul Penrose
Reply to  RMB
April 1, 2019 11:36 am

By “physical heat”, do you mean heat transfer via conduction (transfer of molecular kinetic energy)? If so, I’m not sure “blocked” is the correct term, but certainly that transfer method is quite inefficient at the gas-liquid interface. Practically speaking, this means that a warming atmosphere has little effect on bodies of water, but it is not zero.

Paul Penrose
Reply to  RMB
April 1, 2019 11:44 am

To add to my previous comment; your bucket of water analogy is flawed. The hot air from the heat gun will rapidly dissipate into the surrounding air, which is not the same as a uniformly warmer atmosphere. A better comparison would be to put a saucer filled with water into a convection oven. If left in there long enough, the water will heat up. But if you cycle it on a daily basis, you would probably need to set the oven to unrealistic values (comparatively) above ambient to notice any warming.

Smart Rock
April 1, 2019 9:26 pm

Sometimes I daydream about a near future where the great global warming conspiracy is unmasked, and sanity begins to drive the energy policies of democratically elected governments.

But what would all these climate scientists (so-called) do in a world like that?

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