Reposted from Dr Roy Spencer’s Blog
May 13th, 2019 by Roy W. Spencer, Ph. D.
A major uncertainty in figuring out how much of recent warming has been human-caused is knowing how much nature has caused. The IPCC is quite sure that nature is responsible for less than half of the warming since the mid-1900s, but politicians, activists, and various green energy pundits go even further, behaving as if warming is 100% human-caused.
The fact is we really don’t understand the causes of natural climate change on the time scale of an individual lifetime, although theories abound. For example, there is plenty of evidence that the Little Ice Age was real, and so some of the warming over the last 150 years (especially prior to 1940) was natural — but how much?
The answer makes as huge difference to energy policy. If global warming is only 50% as large as is predicted by the IPCC (which would make it only 20% of the problem portrayed by the media and politicians), then the immense cost of renewable energy can be avoided until we have new cost-competitive energy technologies.
The recently published paper Recent Global Warming as Confirmed by AIRS used 15 years of infrared satellite data to obtain a rather strong global surface warming trend of +0.24 C/decade. Objections have been made to that study by me (e.g. here) and others, not the least of which is the fact that the 2003-2017 period addressed had a record warm El Nino near the end (2015-16), which means the computed warming trend over that period is not entirely human-caused warming.
If we look at the warming over the 19-year period 2000-2018, we see the record El Nino event during 2015-16 (all monthly anomalies are relative to the 2001-2017 average seasonal cycle):
We also see that the average of all of the CMIP5 models’ surface temperature trend projections (in which natural variability in the many models is averaged out) has a warmer trend than the observations, despite the trend-enhancing effect of the 2015-16 El Nino event.
So, how much of an influence did that warm event have on the computed trends? The simplest way to address that is to use only the data before that event. To be somewhat objective about it, we can take the period over which there is no trend in El Nino (and La Nina) activity, which happens to be 2000 through June, 2015 (15.5 years):
Note that the observed trend in HadCRUT4 surface temperatures is nearly cut in half compared to the CMIP5 model average warming over the same period, and the UAH tropospheric temperature trend is almost zero.
One might wonder why the UAH LT trend is so low for this period, even though in Fig. 1 it is not that far below the surface temperature observations (+0.12 C/decade versus +0.16 C/decade for the full period through 2018). So, I examined the RSS version of LT for 2000 through June 2015, which had a +0.10 C/decade trend. For a more apples-to-apples comparison, the CMIP5 surface-to-500 hPa layer average temperature averaged across all models is +0.20 C/decade, so even RSS LT (which usually has a warmer trend than UAH LT) has only one-half the warming trend as the average CMIP5 model during this period.
So, once again, we see that the observed rate of warming — when we ignore the natural fluctuations in the climate system (which, along with severe weather events dominate “climate change” news) — is only about one-half of that projected by climate models at this point in the 21st Century. This fraction is consistent with the global energy budget study of Lewis & Curry (2018) which analyzed 100 years of global temperatures and ocean heat content changes, and also found that the climate system is only about 1/2 as sensitive to increasing CO2 as climate models assume.
It will be interesting to see if the new climate model assessment (CMIP6) produces warming more in line with the observations. From what I have heard so far, this appears unlikely. If history is any guide, this means the observations will continue to need adjustments to fit the models, rather than the other way around.
Is there a chart showing the frequency and severity of ENSOs over the last 50 years, and if so, has there been an increase in one or both?
This is NOAA data on ENSO.
https://origin.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_v5.php
Thanks R.
I don’t see much to get to exited about there.
The long term original MEI image for 1870-2005. This MEI image for 1950-2018 was recently obsoleted by the new MEI v2.
Overall the MEI v1 since 1950 was greater than zero 52% of the time; 62% of those months were >0.5, and 54% of all values exceeding 0.5 or below -0.5 were greater than 0.5; trend slope of 0.001.
I agree with Dr. Spencer.
From mid-1996~mid-2015, the global warming trend was 0.00C/decade, despite 30% of all man made CO2 emissions since 1750 being made over those 19 years.
The 2015/16 Super El Niño caused an anomalous and natural global warming temperature spike, which ended this 19-year hiatus. Moreover, because the following La Niña was a dud, the remnants of this Super El Niño still remains.
Fortunately, the 2018/19 El Niño was a complete dud, and there is a high probability the next La Niña cycle will be a strong one because there is usually at least one strong La Niña cycle every 10 years, and the last one was 2010/11.
Moreover, a new 30-year PDO cool cycle is about to start, which means future El Niños will tend to be weaker and La Niña cycles will tend to be stronger, which will lead global cooling. Additionally, the AMO and AOO are also about to enter their respective 30-year cool cycles, which will add to a global cooling cycle.
A 50-year Grand Solar Minimum cycle also just started, and if the Svensmark Effect exists, this will add to global cooling.
By the end of Trump’s second term, the 45-year UAH 6.0 global temperature trend should be around 0.07C/decade, and the disparity between CMIP5 warming projections vs. UAH 6.0 will exceed 2~3 standard deviations for almost 30 years, which is more than enough to officially disconfirm this stupid CAGW Hoax.
The next 5 years should be very ingesting.
No one should be counting on unrealized 30 year cycles, nor a 50 year GSM, or the Svensmark effect.
We are nowhere near GSM territory, the last one being the Maunder minimum, and the sunspot activity in SC24 was higher than the Dalton minimum, with the next cycle expected to be similar to the last. The GSM hoax craze should end by the top of the next cycle.
Bob-san:
1) The strongest 63-year Grand Solar Maximum in 11,400 years occurred from 1933~1996.
Even if an actual 50-year Grand Solar Minimum hasn’t just started, the end of the 1933~96 Grand Solar Maximum should have a cooling effect, which is supported by the 1996~2015 Hiatus, which was only ended by the 2015/16 Super El Niño event, and will very likely be negated by the next strong La Niña event.
2) 30-year PDO, AMO and AOO warm/cool cycles do affect global temps, and follow perfectly 30-year global warming/cooling cycles. That’s why the warming trend from 1913~1945 during the last 30-year PDO warm cycle was almost exactly the same as the from 1979~2010, when man made CO2 emissions were too low to have caused any CO2 forcing early last century.
When the ocean cycles are once again in their respective 30-year cool cycles, we’ll see global cooling trends, as we did from 1880~1910, and from 1945~1978…
Cheers.
Bob Weber
Thanks.
So let us get this straight, Bindidon is saying with his list of December January & February Average temperatures that the average temperatures for 1 quarter of the year for
2015 10.22
1991 10.23
2012 10.37
2018 10.48
1997 11.06
2002 11.79
1992 12.18
2017 12.24
1995 12.81
2000 12.97
1999 13.77
2016 14.26
1998 14.28
compared to
1918 -5.43
1936 -5.21
1917 -4.31
1929 -3.5
1893 -3.17
1905 -2.25
so we are talking about a swing of almost 20 degrees between 1918, 1917 & 1936 up to 1998, 1999 & 2016.
If this were in fact true, surely the impact on the Annual Average Global Temperatures of that period would be significantly higher than the approximately 1.2C that every single Dataset shows.
Sorry but this just does not compute.
I have read that there is evidence that two civilizations were possibly lost due to lengthy el nino and la nina around 600 BC. So well before the industrial revolution.
https://www.newscientist.com/article/mg12517063-100-science-el-nino-events-devastated-two-ancient-civilisations/
ColinD
“So well before the industrial revolution.”
Who pretends the contrary? Informed people know of El Nino / La Nina stats going back to around 1500 AD.
Bindidion:
“Who pretends the contrary? Informed people know of El Nino/La Nina stats going back to around 1500 AD”
Yes, and throughout much of Earth’s history.
Essentially all La Ninas and El Ninos are caused by VEI4 or larger volcanic eruptions (exceptions are the man-made ones, mostly since circa 1975).
As such, they are NOT cyclic events, being triggered primarily by random volcanic eruptions.
The mechanism is simply the increasing or decreasing levels of Sulfur Dioxide aerosols in the atmosphere.
An explosive eruption spews SO2 into the stratosphere, which converts to SO2 aerosols, which have a strongly dimming effect, usually causing a La Nina about a year after the eruption.
When these aerosols eventually settle out, the atmosphere becomes more transparent, and warming occurs, often causing a volcanic-induced El Nino, about 2 years after the eruption.
Increased warming can also occur if there are extended intervals (>3-4 years) between VEI4 eruptions, due the to the more complete settling out the of any circulating aerosols (longer intervals for larger eruptions).
Since La Ninas and El Ninos are temporary events, their effects should not be included in any estimates of rising global temperatures.
https://wattsupwiththat.com/2019/05/16/half-of-21st-century-warming-due-to-el-nino/#comment-2703555
I don’t understand how you can claim that half the warming is caused by ENSO when you ignore all but a single ENSO event. Until 2015 ENSO had been generally declining so if it accounted for 50% of all temperature changes that would have a big impact in the warming rate up to 2015.
Out of curiosity I did my own rather simple analysis using linear regression.
For UAH since 2000 annual warming has been 1.29°C / century.
But factoring in ENSO into the model reduces the time component to 1.17°C / century.
This would suggest to me that ENSO has been responsible for around 10% of the warming seen since 2000, not half.
If you look at the whole of the satellite era since 1979, removing the effects of ENSO would slightly increase the amount of warming to 1.35°C / century.
I am wondering about the relationship of undersea volcanos and El Nino. The recent eruption of Kiluaea and lava flow is graphic evidence of amount of heat that is available from the core of our Earth.
CJ Henderson
“The recent eruption of Kiluaea and lava flow is graphic evidence of amount of heat that is available from the core of our Earth.”
It is imho a bit dangerous to extrapolate that from a single place.
On average, the core’s flux is 80 mW/m², what you should compare to the 240 W/m² by solar irradiance reaching the surface.
What the figure above is telling us is that whenever the relative strength and/or frequency of the El Niño events are greater than that of the La Niña events (i.e. the cumulative MEI is trending positive) then global mean temperatures increase, and that whenever the relative strength and/or frequency of the La Niña events are greater than that of the El Niño events (i.e. the cumulative MEI is trending negatively) then global mean temperature decreases.
Hence, I believe that this figure supports the claims made by Wilson [2013, 2019], Tisdale[2012], and the subsequent claims of de Freitas and McLean [2013].
Wilson, I.R.G., 2013, Are Global Mean Temperatures Significantly Affected by Long-Term Lunar Atmospheric Tides? Energy & Environment, Vol 24, No. 3 & 4, pp. 497 – 508.
Tisdale R., Who turned up the heat? – The unsuspecting global-warming culprit – El Niño-Southern Oscillation, 2012
http://astroclimateconnection.blogspot.com/2011/12/world-mean-temperature-warmscools.html, Last accessed 24/01/2019
de Freitas, C.R. and McLean, J.D., Update of the chronology of natural signals in the near-surface mean global temperature record and the Southern Oscillation Index, International Journal of Geosciences, 2013, 4(1), 234-239.
A C Osborn
Neither did you read my comments carefully enough, nor do you seem to know much about the differences between
– the Northern Hemisphere and the Globe;
– a winter average and a full year average.
Please have a look at the following graph which might explain you a lot concerning these differences:
https://drive.google.com/file/d/161n0XmKIVr4VYgOCFHRl7TicsoMuG4nl/view
In blue you see what I was talking about (DJF average over the NH)
In red you see the DJF average for the Globe.
And in green you see what you manifestly were talking about: a full year average for the Globe.
Linear estimates for the indicated period (1881-2018), in °C per decade:
– blue: 0.73 ± 0.07
– red: 0.62 ± 0.06
and…
– green: 0.05 ± 0.02 { this trend is very low, due to absolute values hiding the stronger minima increases }
*
“Sorry but this just does not compute.”
I guess it does, doesn’t it?
Rgds
J.-P. D.
Oops!
– blue: 0.62 ± 0.06
– red: 0.73 ± 0.07
Yeah, it’s 2 AM here 🙂
Other examples of non-intuitive output from nonlinear dynamical systems can be found it the book by Albert Goldbeter titled “Biochemical Oscillations and Cellular Rhythms: The molecular basis of periodic and chaotic behavior”. For example, square waves and asymmetric saw-waves.
The climate system is a self-assembled system of interacting non-linear dissipative systems, with energy flows and mass flows, not one system of which has been reasonably thoroughly characterized in terms of either heat or mass flows. To say which of such concurrent processes might be the “result” or “cause” of another requires more information than is currently available.
To say which of such concurrent processes might be the “result” or “cause” of another requires more information than is currently available.
Actually there is enough information available, it just has to be properly organized. Heat flows from the tropics, powered by sunshine, riding solar activity peaks and valleys. Start looking at the annual insolation cycle to appreciate organized heat flows.
While there is a certain amount of chaotic behavior, all irregularities do smooth out to a linear ocean response to TSI at nominally 0.5C/W/yr, based on the annual TSI Jan-Dec change, and the rate of TSI change at the cycle onset which drives the subsequent cycle onset El Nino.
Overall the climate changes deterministically based on simple logical rules, with daily noise.
The change rates of multi-decadal ocean warming/cooling periods have similar linear slopes to concurrent net solar forcing when my solar-ocean sensitivity factor is taken into account.
The annual TSI change during the solar minimum years is very small, thus the annual SST changes are very small at the minimum. The build-up of TSI to the solar maximum builds up the SST until TSI falls, then the ocean cools, very predictably, dependent solely on solar timing and strength.
Climate is easy to understand, it’s just taken this long to get all the proper data together and to organize it correctly – accomplished only by essentially ignoring the invalid CO2 theory.
Climate and solar scientists have spent 4 decades confusing themselves and everyone else, which is why people think it’s chaotic.
Bob Weber: Climate is easy to understand,
Climate processes are hard to model accurately. That they are high dimensional nonlinear dissipative systems is undeniable, and such high dimensional nonlinear dissipative systems are chaotic.
Hence my claim that there is no adequate justification for the claim that 50% of warming since the late 1800s can be reliably assigned to this or that cause.
invalid CO2 theory.
There is nothing invalid in the measured absorption/emission spectra of CO2, or the claim that the absorption and emission processes occur in atmospheric CO2. What’s missing is accurate quantification of the net effects of these processes at the different altitudes/pressures/densities.
Matthew, yes, the processes are hard to model outside of tropical zone where solar radiation has it’s strongest effect. However if one can live with not having a completely reductionist method usually invoked by the IPCC crowd, my macro-climate method does define the dominate solar influence on the climate.
My ‘invalid CO2 theory’ comment is grounded in the understanding that CO2 is overwhelmingly driven by ocean temperature, not emissions, so that’s why I say the CO2 warming theory is false, ie, invalid.
There is literally zero correlation between NASA’s claimed carbon cycle budget emissions data and atmospheric CO2, whereas the ocean via Henry’s Law cross-correlates at a peak lagged 0.8 correlation at 10-12 months. NASA’s numbers add up to 3.2X the amount of the 100ppm atmospheric change just from burnt fuels over the time of their data, so imo is vastly overestimated. The implication of NASA’s CO2 budget is Henry’s Law is completely overwhelmed by emissions, which is clearly wrong as CO2 12mo change is responding almost entirely to SST, and not to man-made emissions.
NASA is wrong on so many levels it ain’t funny.
If Roy bothered to calculate confidence intervals for this data, readers would realize that most, if not all, of the trend differences he discusses above are not statistically significant. The 95% ci (correcting for autocorrelation) for UAH and HadCRUT4 for both periods starting in 2000 is about 0.10 and 0.07 degC/decade, so the difference between these trends certainly could be due to chance – based on the scatter in the data BEFORE the El Nino! If we formally calculate the difference in trend before the El Nino and for the full period, I get:
0.11 +/- 0.14 degC/decade for UAH
0.06 +/- 0.09 degC/decade for HadCRUT4
This is approximately like saying that 50+/-75% of 21st-century warming is due to the recent El Nino. Pretty meaningless.
At the end of this blog, Roy gets around to the key issue:
“So, once again, we see that the observed rate of warming — when we ignore the natural fluctuations in the climate system (which, along with severe weather events dominate “climate change” news) — is only about one-half of that projected by climate models at this point in the 21st Century. This fraction is consistent with the global energy budget study of Lewis & Curry (2018) which analyzed 100 years of global temperatures and ocean heat content changes, and also found that the climate system is only about 1/2 as sensitive to increasing CO2 as climate models assume.
It will be interesting to see if the new climate model assessment (CMIP6) produces warming more in line with the observations. From what I have heard so far, this appears unlikely. If history is any guide, this means the observations will continue to need adjustments to fit the models, rather than the other way around.”
If one considers the satellite era since 1979, trends are better defined and differ only modestly: RSS 0.20+/-0.04 K/decade; HadCRUT4 0.17+/-0.02 K decade, and UAH 0.13+/-0.04 K/decade. Work with energy balance models such as Lewis and Curry’s show a central estimate for TCR of 1.3 K/doubling, while the average CMIP5 AOGCM shows 1.8 K/doubling. So their work shows that transient climate sensitivity is 28% – not 50% – less than the average CIMP5 model. So how can CMIP5 models project only 0.18 K/decade of current warming, essentially the same as has been observed by HadCRUT4, 0.17 K/decade? That’s because most models have been programmed to produce a larger aerosol indirect effect than was judged appropriate by AR5. It will be interesting to see if the CMIP6 models continue this practice. In the real world, aerosol forcing have plateaued and begun falling since about 2000, but aerosol levels input into historic CMIP5 runs may not have included this change.
The other difference in climate sensitive is due to ocean heat uptake: TCR/ECS = 1 – dQ/dF, where dQ is ocean heat uptake and dF is the change in forcing. For models TCR/ECS is 1.8/3.3 = 0.55, but dQ/dF is about 0.7 based on data from ARGO.
As best I can tell, Roy is wasting his and our time whining about the 15/16 El Nino. The CMIP5 models do a decent job of agreeing with observed warming because they inflate the aerosol indirect effect and because they send too much heat into the ocean. Both factors inflate projected future warming. The 15/16 El Nino and The Pause that preceded it are irrelevant.
As best I can tell, Roy is wasting his and our time whining about the 15/16 El Nino. The CMIP5 models do a decent job of agreeing with observed warming because they inflate the aerosol indirect effect and because they send too much heat into the ocean. Both factors inflate projected future warming. The 15/16 El Nino and The Pause that preceded it are irrelevant.
He is not wasting our time, but you are. The pause occurred from insufficient solar minimum forcing under 1361.25 W/m2 SORCE 1au TSI from 2004 to 2011, and the El Nino was forced by solar maximum TSI above that level.
That Curry and Lewis and so many others think CO2 warms the ocean is what is irrelevant. The only important sensitivity factor is that of the ocean to solar forcing.
The models you speak of are junk science, irrespective of your hand-waving.
Bob: If the solar minimum in the 2000’s were responsible for the Pause, why didn’t previous solar minimum cause Pauses? Why can’t anyone (including Willis) find a signal for the solar cycle in the record of GMST?
Bob wrote: “That Curry and Lewis and so many others think CO2 warms the ocean is what is irrelevant. The only important sensitivity factor is that of the ocean to solar forcing.”
Energy is energy, it doesn’t make any different if it comes from the sun as SWR or from the atmosphere as DLR, or from reduced radiative cooling to space (radiative forcing). Temperature is proportional to internal energy.
It is true that DLR doesn’t penetrate below the top mm of the ocean, but that same top mm is losing an average of 390 W/m2 to OLR (radiative cooling) and 100 W/m2 of latent and sensible heat. Most SWR does penetrate below the top mm before being absorbed, but that heat is convected to the surface when it cools at night.
Bob wrote: “The models you speak of are junk science, irrespective of your hand-waving.”
My comment wasn’t intended to endorse or reject AOGCMs (which are based on reliable physics, but require parameters and tuning). My comment was intended to explain why models can project a current warming rate of 0.18 K/decade (as Roy points out, similar to what is currently observed), but seriously disagree with the TCR and ECS obtained by Lewis and Curry from observed warming. Roy’s explanation is that El Nino is inflating the current warming rate so that it matches the projections of models. However, the warming rate for the last half-century has been about 0.18 K/decade and a single El Nino has little effect on that warming rate. (UAH says a little lower, 0.14 K/decade, and RSS a little higher, 2.0 K/decade.) The period of slow warming in the 2000’s is an abnormality that is not surprising in light of the variability seen in other periods.
Models project only modest current warming because they include too large an aerosol indirect effect (making clouds more reflective) and they send too much heat into the deep ocean.
The current ENSO outlook at BOM shows a remarkably fast outbreak of subsurface cold across the whole equatorial Pacific from east to west:
http://www.bom.gov.au/climate/enso/#tabs=Sea-sub–surface
The outlooks are for cooling both of the Nino regions and also the Indian Ocean – unusual for them both to be cooling simultaneously, usually there is reciprocity between the east-central Pacific and the Indian Ocean.
http://www.bom.gov.au/climate/enso/#tabs=Outlooks
With such an outlook it’s odd to hear people in some quarters still talking up an El Niño. ENSO is going negative, fast.