SVENSMARK’s Force Majeure, The Sun’s Large Role in Climate Change

Reblogged from Watts Up With That:

GUEST: HENRIK SVENSMARK

By H. Sterling Burnett

By bombarding the Earth with cosmic rays and being a driving force behind cloud formations, the sun plays a much larger role on climate than “consensus scientists” care to admit.

The Danish National Space Institute’s Dr. Henrik Svensmark has assembled a powerful array of data and evidence in his recent study, Force Majeure the Sun’s Large Role in Climate Change.

The study shows that throughout history and now, the sun plays a powerful role in climate change. Solar activity impacts cosmic rays which are tied to cloud formation. Clouds, their abundance or dearth, directly affects the earth’s climate.

Climate models don’t accurately account for the role of clouds or solar activity in climate change, with the result they assume the earth is much more sensitive to greenhouse gas levels than it is. Unfortunately, the impact of clouds and the sun on climate are understudied because climate science has become so politicized.

Full audio interview here:  Interview with Dr. Henrick Svensmark

 

H. Sterling Burnett, Ph.D. is a Heartland senior fellow on environmental policy and the managing editor of Environment & Climate News.

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Analysis of new NASA AIRS study: 80% of U.S. Warming has been at Night

Reblogged from Watts Up With That:

By Dr. Roy Spencer

I have previously addressed the NASA study that concluded the AIRS satellite temperatures “verified global warming trends“. The AIRS is an infrared temperature sounding instrument on the NASA Aqua satellite, providing data since late 2002 (over 16 years). All results in that study, and presented here, are based upon infrared measurements alone, with no microwave temperature sounder data being used in these products.

That reported study addressed only the surface “skin” temperature measurements, but the AIRS is also used to retrieve temperature profiles throughout the troposphere and stratosphere — that’s 99.9% of the total mass of the atmosphere.

Since AIRS data are also used to retrieve a 2 meter temperature (the traditional surface air temperature measurement height), I was curious why that wasn’t used instead of the surface skin temperature. Also, AIRS allows me to compare to our UAH tropospheric deep-layer temperature products.

So, I downloaded the entire archive of monthly average AIRS temperature retrievals on a 1 deg. lat/lon grid (85 GB of data). I’ve been analyzing those data over various regions (global, tropical, land, ocean). While there are a lot of interesting results I could show, today I’m going to focus just on the United States.

AIRS temperature trend profiles averaged over the contiguous United States, Sept. 2002 through March 2019. Gray represents an average of day and night. Trends are based upon monthly departures from the average seasonal cycle during 2003-2018. The UAH LT temperature trend (and it’s approximate vertical extent) is in violet, and NOAA surface air temperature trends (Tmax, Tmin, Tavg) are indicated by triangles. The open circles are the T2m retrievals, which appear to be less trustworthy than the Tskin retrievals.

Because the Aqua satellite observes at nominal local times of 1:30 a.m. and 1:30 p.m., this allows separation of data into “day” and “night”. It is well known that recent warming of surface air temperatures (both in the U.S. and globally) has been stronger at night than during the day, but the AIRS data shows just how dramatic the day-night difference is… keeping in mind this is only the most recent 16.6 years (since September 2002):

The AIRS surface skin temperature trend at night (1:30 a.m.) is a whopping +0.57 C/decade, while the daytime (1:30 p.m.) trend is only +0.15 C/decade. This is a bigger diurnal difference than indicated by the NOAA Tmax and Tmin trends (triangles in the above plot). Admittedly, 1:30 a.m. and 1:30 pm are not when the lowest and highest temperatures of the day occur, but I wouldn’t expect as large a difference in trends as is seen here, at least at night.

Furthermore, these day-night differences extend up through the lower troposphere, to higher than 850 mb (about 5,000 ft altitude), even showing up at 700 mb (about 12,000 ft. altitude).

This behavior also shows up in globally-averaged land areas, and reverses over the ocean (but with a much weaker day-night difference). I will report on this at some point in the future.

If real, these large day-night differences in temperature trends is fascinating behavior. My first suspicion is that it has something to do with a change in moist convection and cloud activity during warming. For instance more clouds would reduce daytime warming but increase nighttime warming. But I looked at the seasonal variations in these signatures and (unexpectedly) the day-night difference is greatest in winter (DJF) when there is the least convective activity and weakest in summer (JJA) when there is the most convective activity.

One possibility is that there is a problem with the AIRS temperature retrievals (now at Version 6). But it seems unlikely that this problem would extend through such a large depth of the lower troposphere. I can’t think of any reason why there would be such a large bias between day and night retrievals when it can be seen in the above figure that there is essentially no difference from the 500 mb level upward.

It should be kept in mind that the lower tropospheric and surface temperatures can only be measured by AIRS in the absence of clouds (or in between clouds). I have no idea how much of an effect this sampling bias would have on the results.

Finally, note how well the AIRS low- to mid-troposphere temperature trends match the bulk trend in our UAH LT product. I will be examining this further for larger areas as well.

The Cooling Rains

Reblogged from Watts Up With That:

Guest Post by Willis Eschenbach

I took another ramble through the Tropical Rainfall Measurement Mission (TRMM) satellite-measured rainfall data. Figure 1 shows a Pacific-centered and an Atlantic-centered view of the average rainfall from the end of 1997 to the start of 2015 as measured by the TRMM satellite.

Figure 1. Average rainfall, meters per year, on a 1° latitude by 1° longitude basis. The area covered by the satellite data, forty degrees north and south of the Equator, is just under 2/3 of the globe. The blue areas by the Equator mark the InterTropical Convergence Zone (ITCZ). The two black horizontal dashed lines mark the Tropics of Cancer and Capricorn, the lines showing how far north and south the sun travels each year (23.45°, for those interested).

There’s lots of interesting stuff in those two graphs. I was surprised by how much of the planet in general, and the ocean in particular, are bright red, meaning they get less than half a meter (20″) of rain per year.

I was also intrigued by how narrowly the rainfall is concentrated at the average Inter-Tropical Convergence Zone (ITCZ). The ITCZ is where the two great global hemispheres of the atmospheric circulation meet near the Equator. In the Pacific and Atlantic on average the ITCZ is just above the Equator, and in the Indian Ocean, it’s just below the Equator. However, that’s just on average. Sometimes in the Pacific, the ITCZ is below the Equator. You can see kind of a mirror image as a light orange horizontal area just below the Equator.

Here’s an idealized view of the global circulation. On the left-hand edge of the globe, I’ve drawn a cross section through the atmosphere, showing the circulation of the great atmospheric cells.

Figure 2. Generalized overview of planetary atmospheric circulation. At the ITCZ along the Equator, tall thunderstorms take warm surface air, strip out the moisture as rain, and drive the warm dry air vertically. This warm dry air eventually subsides somewhere around 25-30°N and 25-30S of the Equator, creating the global desert belts at around those latitudes.

The ITCZ is shown in cross-section at the left edge of the globe in Figure 2. You can see the general tropical circulation. Surface air in both hemispheres moves towards the Equator. It is warmed there and rises. This thermal circulation is greatly sped up by air driven vertically at high rates of speed through the tall thunderstorm towers. These thunderstorms form all along the ITCZ. These thunderstorms provide much of the mechanical energy that drives the atmospheric circulation of the Hadley cells.

With all of that as prologue, here’s what I looked at. I got to thinking, was there a trend in the rainfall? Is it getting wetter or drier? So I looked at that using the TRMM data. Figure 3 shows the annual change in rainfall, in millimeters per year, on a 1° latitude by 1° longitude basis.

Figure 3. Annual change in the rainfall, 1° latitude x 1° longitude gridcells.

I note that the increase in rain is greater on the ocean vs land, is greatest at the ITCZ, and is generally greater in the tropics.

Why is this overall trend in rainfall of interest? It gives us a way to calculate how much this cools the surface. Remember the old saying, what comes down must go up … or perhaps it’s the other way around, same thing. If it rains an extra millimeter of water, somewhere it must have evaporated an extra millimeter of water.

And in the same way that our bodies are cooled by evaporation, the surface of the planet is also cooled by evaporation.

Now, we note above that on average, the increase is 1.33 millimeters of water per year. Metric is nice because volume and size are related. Here’s a great example.

One millimeter of rain falling on one square meter of the surface is one liter of water which is one kilo of water. Nice, huh?

So the extra 1.33 millimeters of rain per year is equal to 1.33 extra liters of water evaporated per square meter of surface area.

Next, how much energy does it take to evaporate that extra 1.33 liters of water per square meter so it can come down as rain? The calculations are in the endnotes. It turns out that this 1.33 extra liters per year represents an additional cooling of a tenth of a watt per square meter (0.10 W/m2).

And how does this compare to the warming from increased longwave radiation due to the additional CO2? Well, again, the calculations are in the endnotes. The answer is, per the IPCC calculations, CO2 alone over the period gave a yearly increase in downwelling radiation of ~ 0.03 W/m2. Generally, they double that number to allow for other greenhouse gases (GHGs), so for purposes of discussion, we’ll call it 0.06 W/m2 per year.

So over the period of this record, we have increased evaporative cooling of 0.10 W/m2 per year, and we have increased radiative warming from GHGs of 0.06 W/m2 per year.

Which means that over that period and that area at least, the calculated increase in warming radiation from GHGs was more than counterbalanced by the observed increase in surface cooling from increased evaporation.

Regards to all,

w.

As usual: please quote the exact words you are discussing so we can all understand exactly what and who you are replying to.

Additional Cooling

Finally, note that this calculation is only evaporative cooling. There are other cooling mechanisms at work that are related to rainstorms. These include:

• Increased cloud albedo reflecting hundreds of watts/square meter of sunshine back to space

• Moving surface air to the upper troposphere where it is above most GHGs and freer to cool to space.

• Increased ocean surface albedo from whitecaps, foam, and spume.

• Cold rain falling from a layer of the troposphere that is much cooler than the surface.

• Rain re-evaporating as it falls to cool the atmosphere

• Cold wind entrained by the rain blowing outwards at surface level to cool surrounding areas

• Dry descending air between rain cells and thunderstorms allowing increased longwave radiation to space.

Between all of these, they form a very strong temperature regulating mechanism that prevents overheating of the planet.

Calculation of energy required to evaporate 1.33 liters of water.

#latent heat evaporation joules/kg @ salinity 35 psu, temperature 24°C

> latevap = gsw_latentheat_evap_t( 35, 24 ) ; latevap

[1] 2441369

# joules/yr/m2 required to evaporate 1.33 liters/yr/m2

> evapj = latevap * 1.33 ; evapj

[1] 3247021

# convert joules/yr/m2 to W/m2

> evapwm2 = evapj / secsperyear ; evapwm2

[1] 0.1028941

Note: the exact answer varies dependent on seawater temperature, salinity, and density. These only make a difference of a couple percent (say 0.1043 vs 0.1028941). I’ve used average values.

Calculation of downwelling radiation change from CO2 increase.

#starting CO2 ppmv Dec 1997

> thestart = as.double( coshort[1] ) ; thestart

[1] 364.38

#ending CO2 ppmv Mar 2015

> theend = as.double( last( coshort )) ; theend

[1] 401.54

# longwave increase, W/m2 per year over 17 years 4 months

> 3.7 * log( theend / thestart, 2)/17.33

[1] 0.0299117

In Aftermath of Volcanic Eruption, Photosynthesis Waxes, Carbon Dioxide Wanes

From Scientific American:

By Laura Wright on March 28, 2003

 

Read more from this special report:

A Guide to Volcanoes

In June 1991, when Mt. Pinatubo in the Philippines spewed tons of volcanic ash and gases into the atmosphere, it just so happened that halfway around the world scientists were beginning to obtain good data from carbon dioxide monitors high above the tree canopy in Harvard Forest, outside Boston, Mass. Now, more than a decade later, the measurements taken during the years following the eruption are providing new insight into how atmospheric aerosols affect photosynthesis. The findings, published today in the journal Science, are forcing scientists to rethink the factors that influence the cycling of carbon through the environment, particularly carbon dioxide, a major player in global warming.

 

Within three weeks of the Mt. Pinatubo eruption, the largest volcanic blast of the century, a band of sulfur aerosol had encircled the globe. By early 1992, the volcanic gases and aerosols had diffused through the stratosphere, veiling the earth. During that time, global carbon dioxide levels fell more sharply than any other decline on record. Some scientists suggested that global cooling caused ecosystem respiration to drop, lowering the amount of carbon dioxide emitted into the atmosphere. But Lianhong Gu of Oak Ridge National Laboratory, lead author of the Science report, didn’t think that could be the only explanation.

Gu knew that crop scientists had discovered that plants grow best in diffuse light. When sunlight is too intense, some leaves fall into shadow, unable to photosynthesize, while others bask in the direct beams but will reach a photosynthetic saturation point. Moderate cloud cover and aerosols block direct beams, but allow light to bounce back and forth off water vapor and other molecules, creating a “softer” light that reaches leaves that would otherwise be shaded. As a result, the plants photosynthesize more, using up carbon dioxide in the process. Gu and his collaborators determined that the same principles apply to forest canopies. The Harvard Forest data show that carbon dioxide levels dropped for two years following the eruption at Mt. Pinatubo findings that the scientists suggest represent a worldwide phenomenon given that the eruption had a global atmospheric effect. “Up until now we hadn’t linked aerosols and clouds with carbon studies,” Gu says. “In order to understand atmospheric carbon dioxide concentrations, which affect climate, we have to look at how aerosols and clouds affect the global carbon cycle.”

Solar slump continues – NOAA: “we are currently approaching a Maunder-type minimum in solar activity.”

Reblogged from Watts Up With That:

Solar experts predict the Sun’s activity in Solar Cycle 25 to be below average, similar to Solar Cycle 24

April 5, 2019 – Scientists charged with predicting the Sun’s activity for the next 11-year solar cycle say that it’s likely to be weak, much like the current one. The current solar cycle, Cycle 24, is declining and predicted to reach solar minimum – the period when the Sun is least active – late in 2019 or 2020.

Solar Cycle 25 Prediction Panel experts said Solar Cycle 25 may have a slow start, but is anticipated to peak with solar maximum occurring between 2023 and 2026, and a sunspot range of 95 to 130. This is well below the average number of sunspots, which typically ranges from 140 to 220 sunspots per solar cycle.

Graph via Twitter from
NOAA’s Space Weather Workshop

The panel has high confidence that the coming cycle should break the trend of weakening solar activity seen over the past four cycles.

“We expect Solar Cycle 25 will be very similar to Cycle 24: another fairly weak cycle, preceded by a long, deep minimum,” said panel co-chair Lisa Upton, Ph.D., solar physicist with Space Systems Research Corp. “The expectation that Cycle 25 will be comparable in size to Cycle 24   means that the steady decline in solar cycle amplitude, seen from cycles 21-24, has come to an end and that there is no indication that we are currently approaching a Maunder-type minimum in solar activity.”

The solar cycle prediction gives a rough idea of the frequency of space weather storms of all types, from radio blackouts to geomagnetic storms and solar radiation storms. It is used by many industries to gauge the potential impact of space weather in the coming years. Space weather can affect power grids, critical military, airline, and shipping communications, satellites and Global Positioning System (GPS) signals, and can even threaten astronauts by exposure to harmful radiation doses.

Solar Cycle 24 reached its maximum – the period when the Sun is most active – in April 2014 with a peak average of 82 sunspots. The Sun’s Northern Hemisphere led the sunspot cycle, peaking over two years ahead of the Southern Hemisphere sunspot peak.

Solar cycle forecasting is a new science

While daily weather forecasts are the most widely used type of scientific information in the U.S., solar forecasting is relatively new. Given that the Sun takes 11 years to complete one solar cycle, this is only the fourth time a solar cycle prediction has been issued by U.S. scientists. The first panel convened in 1989 for Cycle 22.

For Solar Cycle 25, the panel hopes for the first time to predict the presence, amplitude, and timing of any differences between the northern and southern hemispheres on the Sun, known as Hemispheric Asymmetry. Later this year, the Panel will release an official Sunspot Number curve which shows the predicted number of sunspots during any given year and any expected asymmetry. The panel will also look into the possibility of providing a Solar Flare Probability Forecast.

“While we are not predicting a particularly active Solar Cycle 25, violent eruptions from the sun can occur at any time,” said Doug Biesecker, Ph.D., panel co-chair and a solar physicist at NOAA’s Space Weather Prediction Center.

An example of this occurred on July 23, 2012 when a powerful coronal mass ejection (CME) eruption missed the Earth but enveloped NASA’s STEREO-A satellite.

Powerful eruption from the surface of the sun captured on May 1, 2013. NASA

2013 study estimated that the U.S. would have suffered between $600 billion and $2.6 trillion in damages, particularly to electrical infrastructure, such as power grid, if this CME had been directed toward Earth. The strength of the 2012 eruption was comparable to the famous 1859 Carrington event that caused widespread damage to telegraph stations around the world and produced aurora displays as far south as the Caribbean.

The Solar Cycle Prediction Panel forecasts the number of sunspots expected for solar maximum, along with the timing of the peak and minimum solar activity levels for the cycle. It is comprised of scientists representing NOAA, NASA, the International Space Environment Services, and other U.S. and international scientists. The outlook was presented on April 5 at the 2019 NOAA Space Weather Workshop in Boulder, Colo.

For the latest space weather forecast, visit https://www.swpc.noaa.gov/

Solar variability weakens the Walker cell

Tallbloke's Talkshop

Credit: PAR @ Wikipedia
This looks significant, pointing directly at solar influences on climate patterns. The researchers found evidence that atmosphere-ocean coupling can amplify the solar signal, having detected that wind anomalies could not be explained by radiative considerations alone.

An international team of researchers from United Kingdom, Denmark, and Germany has found robust evidence for signatures of the 11-year sunspot cycle in the tropical Pacific, reports Phys.org.

They analyzed historical time series of pressure, surface winds and precipitation with specific focus on the Walker Circulation—a vast system of atmospheric flow in the tropical Pacific region that affects patterns of tropical rainfall.

They have revealed that during periods of increased solar irradiance, the trade winds weaken and the Walker circulation shifts eastward.

View original post 249 more words

Why climate predictions are so difficult

“The difficulties [in climate modeling Bjorn Stevens of the Hamburg Max Planck Institute for Meteorology] and his fellow researchers face can be summed up in one word: clouds. The mountains of water vapor slowly moving across the sky are the bane of all climate researchers.”

Climate Etc.

by Judith Curry

An insightful interview with Bjorn Stevens.

View original post 1,104 more words

Climate: In Case You Were Wondering

Reblogged from Watts Up With That:

Guest opinion by David Archibald

The global warming hysteria was reaching a crescendo in the lead up to the climate confab in Copenhagen in 2009 when a civic-minded person released the Climategate emails, deflating the whole thing. Those emails demonstrated that the science behind global warming was more like science fiction, concocted from the fevered imaginations of the scientists involved.

Nigh on 10 years have passed since then and we are currently experiencing another peak in the hysteria that seems to be coordinated worldwide. But why? Why now? The global warming scientists have plenty of time on their hands and plenty of money. Idle curiosity would have got some to have a stab at figuring out what is going to happen to climate. Do they see an imminent cooling and they have to get legislation in place before that is apparent?

The passage of those ten years has given us another lot of data points on the global warming. There are now 40 years of satellite measurements of atmospheric temperature and this is how that plots up for the Lower 48 States:

clip_image002

What the graph shows is the departure from the average for the 30 years from 1981 to 2010. The last data point is February 2019 with a result of -0.03 degrees C. So we have had 40 years of global warming and the temperature has remained flat. In fact it is slightly cooler than the long term average. Is it possible to believe in global warming when the atmosphere has cooled? No, not rationally. Is it possible for global warming to be real if the atmosphere has cooled? Again no.

Now let’s look at carbon dioxide which is supposed to be driving the global warming, if it was happening. A lab high up on Mauna Loa in Hawaii has been measuring the atmospheric concentration since 1958. As it is the annual change in concentration that is supposed to be driving global warming let’s see how that plots up:

clip_image004

What it shows is that the driving effect has been in a wide band from 1979 when the satellites to measure temperature went up but the trend is flat. Think about that – 40 years of forcing and no result in the actual atmospheric temperature. If it was ever going to happen it would have happened by now.

The opposite of global warming is global cooling. What are the chances of that? Pretty good in fact. Only one graph is need to show the potential for that – the aa Index which is a measure of the Sun’s magnetic field strength. Records of that have been kept since 1868:

clip_image006

The second half of the 20th century had a solar magnetic field strength that was 50% higher than that of the last 60 years of the Little Ice Age. That ended in 2006. We are now back to the solar activity levels of the 19th century and that may bring the sort of climate our forbears had then.

And so it has come to pass. January-February had record cold over North America. Seemingly the polar vortex was everywhere because Japan also had record cold.

Waiting for global warming to happen is like Waiting for Godot. It is never going to happen and the wait is getting beyond tedious.

In the meantime there is no evidence for global warming and the opposite is happening, as shown by the record cold we have just experienced. It is time to stop giving global warmers the benefit of doubt – they are loons. That includes Rick Perry.


David Archibald has lectured on climate science in both Senate and House hearing rooms.

Satellite Evidence Affirms Solar Activity Drove ‘A Significant Percentage’ Of Recent Warming

Reblogged from the NoTricksZone:

In a new paper, two astrophysicists shred the IPCC-preferred and model-based PMOD solar data set and affirm the ACRIM, which is rooted in observation and shows an increase in total solar irradiance (TSI) during the 1980-2000 period. They suggest a “significant percentage” of recent climate change has been solar-driven.

Scafetta and Willson, 2019

I. The PMOD is based on proxy modeled predictions, “questionable” modifications, and degraded, “misinterpreted” and “erroneously corrected” results 

• “The PMOD rationale for using models to alter the Nimbus7/ERB data was to compensate for the sparsity of the ERBS/ERBE data and conform their gap results more closely to the proxy predictions of solar emission line models of TSI behavior.”
• “PMOD’s modifications of the published ACRIM and ERB TSI records are questionable because they are based on conforming satellite observational data to proxy model predictions.”
• “The PMOD trend during 1986 to 1996 is biased downward by scaling ERB results to the rapidly degrading ERBE results during the ACRIM-Gap using the questionable justification of agreement with some TSI proxy predictions first proposed by Lee III et al.(1995).”
• PMOD misinterpreted and erroneously corrected ERB results for an instrument power down event.”
• “PMOD used overlapping comparisons of ACRIM1 and ACRIM2 with ERBE observations and proxy models to construct their first composite. Other PMOD composites [17, 18] used different models of the ERBE-ACRIM-Gap degradation. The result of these various modifications during the ACRIM-Gap was that PMOD introduced a downward trend in the Nimbus7/ERB TSI data that decreased results by 0.8 to 0.9 W/m2 (cf. [18, 20]).”

II. The PMOD TSI composite “flawed” results were an “unwarranted manipulation” of data intended to support AGW, but are  “contraindicated”

• “The dangers of utilizing ex-post-facto corrections by those who did not participate in the original science teams of satellite experiments are that erroneous interpretations of the data can occur because of a lack of detailed knowledge of the experiment and unwarranted manipulation of the data can be made based on a desire to support a particular solar model or some other nonempirical bias. We contend that the PMOD TSI composite construction is compromised in both these ways.”
 “[O]ur scientific knowledge could be improved by excluding the more flawed record from the composite. This was the logic applied by the ACRIM team. In point of fact PMOD failed to do this, instead selecting the ERBE results that were known to be degraded and sparse, because that made the solar cycle 21–22 trend agrees with TSI proxy models and the CAGW explanation of CO2 as the driver of the global warming trend of the late 20th century.”
• “The use of unverified modified data has fundamentally flawed the PMOD TSI satellite composite construction.”
• “The consistent downward trending of the PMOD TSI composite is negatively correlated with the global mean temperature anomaly during 1980–2000. This has been viewed with favor by those supporting the COanthropogenic global warming (CAGW) hypothesis since it would minimize TSI variation as a competitive climate change driver to CO2, the featured driver of the hypothesis during the period (cf.: [IPCC, 2013, Lockwood and Fröhlich, 2008]).”
• “Our summary conclusion is that the objective evidence produced by all of the independent TSI composites [3,5, 6, 9] agrees better with the cycle-by-cycle trending of the original ACRIM science team’s composite TSI that shows an increasing trend from 1980 to 2000 and a decreasing trend thereafter. The continuously downward trending of the PMOD composite and TSI proxy models is contraindicated.”

III. The ACRIM TSI supports the conclusion that “a significant percentage” of climate change in recent decades was driven by TSI variation

Graph Source: Soon et al., 2015
• ACRIM shows a 0.46 W/m2 increase between 1986 and 1996 followed by a decrease of 0.30 W/m2 between 1996 and 2009. PMOD shows a continuous, increasing downward trend with a 1986 to 1996 decrease of 0.05 W/m2 followed by a decrease of 0.14 W/m2 between 1996 and 2009. The RMIB composite agrees qualitatively with the ACRIM trend by increasing between the 1986 and 1996 minima and decreasing slightly between 1996 and 2009.”
• “ACRIM composite trending is well correlated with the record of global mean temperature anomaly over the entire range of satellite observations (1980–2018) [Scafetta. 2009]. The climate warming hiatus observed since 2000 is inconsistent with CO2 anthropogenic global warming (CAGW) climate models [Scafetta, 2013, Scafetta, 2017]. This points to a significant percentage of the observed 1980–2000 warming being driven by TSI variation [Scafetta, 2009, Willson, 2014, Scafetta. 2009]. A number of other studies have pointed out that climate change and TSI variability are strongly correlated throughout the Holocene including the recent decades (e.g., Scafetta, 2009,  Scafetta and Willson, 2014, Scafetta, 2013Kerr, 2001, Bond et al., 2001, Kirkby, 2007, Shaviv, 2008, Shapiro et al., 2011, Soon and Legates, 2013, Steinhilber et al., 2012, Soon et al., 2014).”
• “The global surface temperature of the Earth increased from 1970 to 2000 and remained nearly stable from 2000 and 2018. This pattern is not reproduced by CO2 AGW climate models but correlates with a TSI evolution with the trending characteristics of the ACRIM TSI composite as explained in Scafetta [6,12, 27] and Willson [7].”

IV. The Correlation:

Graph Source: Soon et al., 2015
Image Source: Smith, 2017

V. The Mechanism: Higher solar activity on decadal-scales limits the seeding of clouds, which means more solar radiation is absorbed by the surface, warming the Earth 

Image Source: Fleming, 2018

Image Source: Sciencedaily.com

VI. The radiative forcing from the increase in surface solar radiation: +4.25 Wm-2/decade between 1984-2000

Image Source: Goode and Palle, 2007

Image Source(s): Hofer et al., 2017 and Kay et al., 2008

Experts reveal that clouds have moderated warming triggered by climate change

Reblogged from Watts Up With That:

A new study has revealed how clouds are modifying the warming created by human-caused climate change in some parts of the world

Swansea University

196481_web

Trees are removed from cold lake beds in Scandinavia. Credit: Professor Mary Gagen, Swansea University

A new study has revealed how clouds are modifying the warming created by human-caused climate change in some parts of the world.

Led by Swansea University’s Tree Ring Research Group, researchers from Sweden, Finland and Norway analysed information contained in the rings of ancient pine trees from northern Scandinavia to reveal how clouds have reduced the impact of natural phases of warmth in the past and are doing so again now to moderate the warming caused by anthropogenic climate change.

Even though northern Scandinavia should be strongly affected by global warming, the area has experienced little summer warming over recent decades – in stark contrast to the hemispheric trend of warming temperatures, which is strongly linked to rising greenhouse gas emissions. According to the study, temperature changes have been accompanied by an increase in cloudiness over northern Scandinavia, which in turn has reduced the impact of warming.

Mary Gagen, Professor of Geography at Swansea University, said: “The surface warming caused by rising greenhouse gases is modified by many complicated feedbacks – one thing changing in response to another – meaning that there are large geographical variations in the temperature of a particular place at a particular time, as the global average temperature rises. One of the most important, and most poorly understood, climate feedbacks is the relationship between temperature and clouds. We might think that, simply, when it is cool it is cloudy, and when it is warm it is sunny, but that is not always the case.”

The research team analysed tree ring records to find out what summer temperatures were like in the past, and how cloudy it was. Using their collected data, the team produced a new reconstruction of summer cloud cover for northern Scandinavia and compared it to existing temperature reconstructions to establish the relationship between temperature and cloud cover.

Professor Mary Gagen said: “Most people know that the width of a tree ring can tell us what the temperature was like in the summer that ring grew, but we can also measure other things in tree rings such as the isotopes of carbon and water that the wood is made from. Isotopes are just different types of an element, the amount of the different isotopes of carbon in the wood tells us how cloudy it was in the summer the tree ring grew. By combining the tree ring width and tree ring carbon measurements we built a record of both past summer temperatures and past summer cloud cover. Summer temperatures in Scandinavia have increased by less than the global average in recent decades because it also got cloudier at the same time, and that modified and reduced the warming. That turns out to also be the case back through time.”

Author Professor Danny McCarroll explained: “We found that over short timescales, increased cloud cover lead to cooler temperatures and vice versa in the past. However, over longer timescales -decades to centuries-we found that in warmer times, such as the medieval, there was increased cloud cover in this part of the world, which reduced local temperatures. The opposite being true in cool periods, such as the Little Ice Age.

“These finding are important as they help to explain the feedback relationship between cloud cover and temperature, which is one of the major uncertainties in modelling future climate. Understanding the past relationship between temperature and cloud cover in this part of the world means we can now predict that, as the global temperature continues to rise, that warming will be moderated in northern Scandinavia by increasing cloud cover. The next step is to find out whether the same is true for other parts of the world.”

Professor Mary Gagen added: “One of the main sources of uncertainty about future climate change is the way that clouds are going to respond to warming, cloud cover has a really big influence on temperature at the surface of the Earth.

“Clouds are going to be critical in modify warming of the climate. In some places, like Scandinavia, it turns out that the summer climate gets cloudier as the planet warms, in other places though it is likely that warming will be enhanced by a reduction in cloudiness which will make the surface of the Earth even warmer. What is really worrying is that climate models have shown that, if greenhouse gas emissions are allowed to continue until there is double or even triple the pre industrial amount of carbon dioxide in the atmosphere, then some of the most important clouds for cooling our planet, the big banks of oceanic clouds that reflect a lot of sunlight back to space, could stop forming altogether and this would really accelerate warming.”

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The study, Cloud Cover Feedback Moderates Fennoscandian Summer Temperature Changes Over the Past 1,000 Years, is published in Geophysical Research Letters.

From EurekAlert!

Public Release: 25-Mar-2019