Beneficial effect of elevated CO2 on tree photosynthesis and growth is often further enhanced by warming

A new report from SPPI & CO2 Science:

For the Full Report in PDF Form, please click here.

[Illustrations, footnotes and references available in PDF version]

Excerpts:

As the atmosphere's CO2 concentration continues to rise, most trees will likely exhibit increased rates of photosynthesis and biomass production, which can subsequently lead to an increase in the amount of timber that will likely be required to meet the growing needs of earth's expanding human population. However, some individuals have predicted that CO2-induced global warming will counteract the growth-promoting effects of atmospheric CO2 enrichment and actually reduce tree growth. Therefore, in order to determine if this widely-trumpeted claim has any validity, we turn to the peer-reviewed scientific literature to both report and summarize the results of several CO2-enrichment studies that were designed to reveal the concurrent effects of elevated CO2 and air temperature on the growth of trees and other woody plants.

The optimum growth temperature for several plants has already been shown to rise substantially with increasing levels of atmospheric CO2

The beneficial effects of elevated CO2 on tree photosynthesis and growth is often further enhanced by elevated air temperatures, which phenomenon can also be assessed during natural seasonal temperature changes.

In the face of rising atmospheric CO2 and temperature (global warming), trees will benefit from elevated CO2 through increased thermotolerance.

In regard to this hypothesis, such would indeed appear to be the case, in light of what is now the well-established fact that most woody plants tend to exhibit their greatest photosynthetic rates at increasingly warmer temperatures as the air's CO2 content continues to rise, as is confirmed by the many studies of this phenomenon discussed above. And in light of Jaramillo et al.'s findings, it is becoming ever more clear that greater warmth and atmospheric CO2concentrations are not the "twin evils" that the world's climate alarmists typically make them out to be. Quite to the contrary, they are just what earth's ecosystems need, in order to make them both more stable and more productive, which characteristics are absolutely essential for sustaining the still-increasing human population of the planet, as well as preserving what yet remains of what one could call wild nature.

In conclusion, the scientific literature of the past few decades continues to indicate that as the air's CO2 content rises, trees will likely exhibit enhanced rates of photosynthesis and biomass production that will not be negated by any global warming that might occur concurrently. In fact, if the ambient air temperature rises, the growth-promoting effects of atmospheric CO2 enrichment will likely rise right along with it. Thus, the future ability of earth's trees to produce greater amounts of biomass and, therefore, more timber products to meet the increasing needs of earth's expanding human population, looks promising indeed, just as long as the atmosphere's CO2 concentration continues to rise.

New review paper finds increased CO2 will enhance growth of grassland plants, even if warming resumes

A new review paper from SPPI and CO2 Science finds "that as the air's CO2 content rises, grassland plants will likely exhibit enhanced rates of photosynthesis and biomass production that will not be diminished by any global warming that might occur concurrently. In fact, if the ambient air temperature does rise, the growth-promoting effects of atmospheric CO2 enrichment will likely rise right along with it, becoming more and more robust in agreement with the experimental observations reviewed by Idso and Idso (1994)." 

For the Full Report in PDF Form, please click here.

[Illustrations, footnotes and references available in PDF version]

As the atmosphere's CO2 concentration continues to rise, most plants tend to exhibit increased rates of photosynthesis and biomass production, including those of various grassland ecosystems. This increase in productivity should increase the amount of forage available for grazing animals and possibly reduce the land area occupied by bare soil in certain environments. However, some people claim that global warming will negate the growth-promoting effects of atmospheric CO2 enrichment and actually stimulate the opposite process of desertification. This summary thus seeks to develop an answer to this important question by reviewing published scientific studies of the photosynthetic and growth responses of grassland plants to atmospheric CO2 enrichment when exposed to higher-than-normal temperatures.

In conclusion, the recent scientific literature continues to indicate that as the air's CO2 content rises, grassland plants will likely exhibit enhanced rates of photosynthesis and biomass production that will not be diminished by any global warming that might occur concurrently. In fact, if the ambient air temperature does rise, the growth-promoting effects of atmospheric CO2 enrichment will likely rise right along with it, becoming more and more robust in agreement with the experimental observations reviewed by Idso and Idso (1994). The future ability of grasslands to produce increasingly greater amounts of forage, and perhaps reclaim areas of barren ground in certain environments, thus looks promising indeed, as long as the air's CO2 content continues to rise.

New paper shows "social benefit of carbon" far exceeds "social cost of carbon"

A new review paper by SPPI and CO2 Science demolishes the Obama "social cost of carbon" trick by demonstrating peer-reviewed science finding the "social benefit of carbon" is $3.17 trillion dollars just from enhanced crop production due CO2 fertilization alone. This does not include the many trillions of dollars in economic benefits to human health & prosperity from inexpensive fossil fuel energy in comparison to renewable energy. The paper demonstrates the "social benefit" of carbon far exceeds the alleged, highly-exaggerated "social cost" of carbon many times over.

For the Full Report in PDF Form, please click here.

[Illustrations, footnotes and references available in PDF version]

Excerpts:

Advancements in technology and scientific expertise that accompanied the Industrial Revolution initiated a great transformation within the global enterprise of agriculture. More efficient machinery and improved plant cultivars, for example, paved the way toward higher crop yields and increased global food production. And with the ever-burgeoning population of the planet, the increase in food production was a welcomed societal benefit. But what remained largely unknown to society at that time, was the birth of an ancillary aid to agriculture that would confer great benefits upon future inhabitants of the globe in the decades and centuries to come. The source of that aid: atmospheric carbon dioxide (CO2).

For a 300-ppm increase in the air’s CO2 content, such benefits typically enhance herbaceous plant biomass by around 30 to 35%, which  represents an important positive externality entirely absent from today’s state-of-the-art SCC calculations.

And as the CO2  concentration of the air continues to rise in the future, this positive externality of enhanced crop production will benefit society in the years, decades, and even centuries to come.

SEA LEVELS

A somewhat related problem with SCC calculations is their inclusion of costs due to sea level rise. Here, it is presumed that rising temperatures from CO2-induced global warming will result in an acceleration of sea level rise that will bring on a host of economic damages. There are  two problems with this projection. First, temperatures are not rising in the manner or degree projected by the models. Second, observations reveal no acceleration of sea level rise over the past century. In fact, just the opposite appears to be occurring in nature.

Holgate (2007), for example, derived a mean global sea level history over the period 1904-2003. According to their calculations, the mean rate of global sea level rise was “larger in the early part of the last century (2.03 ± 0.35 mm/year 1904-1953), in comparison with the latter part (1.45 ± 0.34 mm/year 1954-2003).” In other words, contrary to model projections, the mean  rate of global sea level rise (SLR) has not accelerated over the recent past. If anything, it’s done just the opposite. Such observations are striking, especially considering they have occurred over a period of time when many have claimed that (1) the Earth warmed to a degree that is unprecedented over many millennia, (2) the warming resulted in a net accelerated melting of the vast majority of the world’s mountain glaciers and polar ice caps, and (3) global sea level rose at an ever increasing rate.

In another paper, Boretti (2012) applied simple statistics to the two decades of information contained in the TOPEX and Jason series of satellite radar altimeter data to “better understand if the SLR is accelerating, stable or decelerating.” In doing so, the Australian scientist reports that the rate of SLR is reducing over the measurement period at a rate of -0.11637 mm/year2, and that this deceleration is also “reducing” at a rate of -0.078792 mm/year3 (see Figure 7). And in light of such observations, Boretti writes that the huge deceleration of SLR over the last 10 years “is clearly the opposite of what is being predicted by the models,” and that “the SLR’s reduction is even more pronounced during the last 5 years.” To further illustrate the importance of his findings, he notes that “in order for the prediction of a 100-cm increase in sea level by 2100 to be correct, the SLR must be almost 11 mm/year every year for the next 89 years,” but he notes that “since the SLR is dropping, the predictions become increasingly unlikely,” especially in view of the facts that (1) “not once in the past 20 years has the SLR of 11 mm/year ever been achieved,” and that (2) “the average SLR of 3.1640 mm/year is only 20% of the SLR needed for the prediction of a one meter rise to be correct.”

The real-world data-based results of Holgate and Boretti, as well as those of other researchers (Morner, 2004; Jevrejeva et al., 2006; Wöppelmann et al., 2009; Houston and Dean, 2011), all suggest that rising atmospheric CO2 emissions are exerting no discernible influence on the rate of sea level rise. Clearly, SCC damages that are based on model projections of a CO2-induced acceleration of SLR must be considered inflated and unlikely to occur.

CONCLUSION

It is clear from the material presented in this report that the modern rise in the air’s CO2 content is providing a tremendous economic benefit to global crop production. As Sylvan Wittwer, the father of agricultural research on this topic, so eloquently put it nearly two decades ago:

“The rising level of atmospheric CO2 could be the one global natural resource that is  progressively increasing food production and total biological output, in a world of otherwise diminishing natural resources of land, water, energy, minerals, and fertilizer. It is a means of inadvertently increasing the productivity of farming systems and other photosynthetically  active ecosystems. The effects know no boundaries and both developing and developed countries are, and will be, sharing equally,” for “the rising level of atmospheric CO2 is a universally free premium, gaining in magnitude with time, on which we all can reckon for the foreseeable future” (Wittwer, 1995). 

The relationship described above by Wittwer is illustrated below in Figure 8, where data pertaining to atmospheric CO2 emissions, food production, and human population are plotted. Standardized to a value of unity in 1961, each of these datasets has experienced rapid and interlinked growth over the past five decades. Rising global population has led to rising CO2 emissions and rising CO2 emissions have benefited food production. The very real positive externality of inadvertent atmospheric CO2 enrichment must be considered in all studies examining the SCC; and its observationally-deduced effects must be given premier weighting over the speculative negative externalities presumed to occur in computer model projections of global warming. Until that time, little if any weight should be placed on current SCC calculations.

New review paper finds Medieval Warming Period in China was warmer than modern times

A new review paper by SPPI & CO2 Science:

For the Full Report in PDF Form, please click here.

[Illustrations, footnotes and references available in PDF version]

 Excerpts:

The Medieval Warm Period (MWP) was a global climatic anomaly that encompassed a few centuries on either side of AD 1000, when temperatures in many parts of the world were even warmer than they are currently. The degree of warmth and associated changes in precipitation, however, varied from region to region and from time to time; and, therefore, the MWP was manifest differently in different parts of the planet. In this Summary, what occurred in China is reviewed.

Proxy climate records obtained from twenty prior studies to derive a 2000- year temperature history of the northeastern, southern and western sections of the Tibetan Plateau [reveal], in each case, there was more than one prior 50-year period of time when the mean temperature of each region was warmer than it was over the most recent 50-year period.

In the case of the northeastern sector of the Plateau, all of the maximum-warmth intervals occurred during the Medieval Warm Period.

The temperature of the 20th century in eastern China is still within the threshold of the variability of the last 2000 years, which observation clearly indicates that the Chinese data provide no evidence for the hypothesis that the eastern part of the country's 20th-century warming - or even a small part of it - was human-induced. 

The existence of this millennial-scale oscillation of climate, with its prior periods of higher thanurrent temperatures, clearly demonstrates that there is nothing unusual about earth's present climatic state, except that it is surprisingly cool , considering how much more CO2 there is in the air nowadays than there was during the warmer Medieval and Roman Warm Periods.

During the past two millennia, a warming trend in the 20th century was clearly detected, but the warming magnitude was smaller than the maximum level of the Medieval Warm Period.

What is more, they say that  "the modern warm period has lasted [only] 20 years from 1987 to 2006," and that the annual mean temperature series of China since AD 1880 indicates that the country was actually warmer in the mid- 1940s than it was at the time of their study.

Wang et al.'s work demonstrated - for yet another part of the planet - that late 20th-century warmth even with the help of an extra 100 ppm of CO2, was less than that of the MWP, which makes it extremely difficult to believe that earth's current level of warmth largely owes its existence to anthropogenic CO2 emissions, as the world's climate alarmists continue to claim it does.

In concluding this summary, it should be evident from the results of the many studies reviewed herein that for a considerable amount of time during the Medieval Warm Period, most (if not all) parts of China exhibited warmer conditions than those of modern times. And since those earlier high temperatures were obviously caused by something other than elevated atmospheric CO2 concentrations, whatever was responsible for them could easily be responsible for the warmth of today. Indeed, evidence piled upon evidence speaks to the reality of a global millennial-scale oscillation of climate that is totally independent of the air's CO2 concentration. And, therefore, there is every reason to believe that the most recent warming phase of this cycle, which led to the demise of the Little Ice Age and the birth of the Current Warm Period, was totally natural and not the result of the coincidental increase in the air's CO2 content that was produced by the burning of the fossil fuels that drove the engines of the Industrial Revolution.

New review paper finds greening from CO2 throughout Europe

A new paper from SPPI and CO2 Science reviews the scientific literature on Greening of the Earth in Europe, and concludes, "In considering each of the studies conducted in Europe..., we note that within the context of today's obsession with the ongoing rise in the atmosphere's CO2 content, as well as the many environmental catastrophes it has been predicted to produce, the overwhelmingly positive results [of global greening from CO2] that have been obtained are truly remarkable. And this assessment is even more remarkable in light of the fact that the world's climate alarmists claim the warming of the past quarter-century was unprecedented over the last two millennia or more, and that this phenomenon is the greatest threat ever to be faced by the planet. Apparently, the plants of Europe just don't understand the seriousness of the situation."

For the Full Report in PDF Form, please click here.

[Illustrations, footnotes and references available in PDF version]

Among the many climate-alarmist fears of CO2-induced global warming is the concern that the productivity of the biosphere will decline if global temperatures rise to the extent predicted by computer models. Because of such concern, several researchers have investigated the relationship between temperature, atmospheric CO2, and biospheric productivity across a range of spatial and temporal scales. In this review we examine what has been learned about the subject for locations in Europe.

The recent rise in atmospheric CO2 may already have had significant impacts on productivity, structure and water relations of sclerophyllous shrub vegetation, which tended to offset the detrimental effects of climate change in the region. 

In contrast to model predictions, no single alpine plant species has become extinct, neither in Scandinavia nor in any other part of the world in response to climate warming over the past century.

Considering the results in their totality, the Dutch and Spanish researchers concluded that, over the last two decades of the 20th century, "Europe as a whole has a tendency to greening," and much of it is "seeing an increase in its wood land proportion." 

In considering each of the studies conducted in Europe that are listed above, we note that within the context of today's obsession with the ongoing rise in the atmosphere's CO2 content, as well as the many environmental catastrophes it has been predicted to produce, the overwhelmingly positive results that have been obtained are truly remarkable. And this assessment is even more remarkable in light of the fact that the world's climate alarmists claim the warming of the past quarter-century was unprecedented over the last two millennia or more, and that this phenomenon is the greatest threat ever to be faced by the planet. Apparently, the plants of Europe just don't understand the seriousness of the situation. 

Review paper finds biosphere productivity of the Arctic is thriving due to CO2 fertilization and warming

A new review paper by SPPI and CO2 Science finds "Land-based plants of the Arctic and near-Arctic regions of North America are not headed down the road of environmental degradation and toward extinction, but are thriving, thanks in large part to the ongoing rise in the atmosphere's CO2 concentration and global warming."

For the Full Report in PDF Form, please click here.

[Illustrations, footnotes and references available in PDF version]

Excerpts:

How does the terrestrial vegetation of Earth's natural ecosystems respond to increases in atmospheric temperature and CO2 concentration? We here consider this question as it applies to Arctic and near-Arctic locations in North America.

Their observations simply indicated "a previously undemonstrated capacity for ecosystems to metabolically adjust to long-term (decadal or longer) changes in climate."

It is clear that the productivity of vegetation in the northern reaches of the Northern Hemisphere has been increasing with time.

These several observations would seem to suggest that the entire Circumpolar Arctic is in the process of returning to what could be called the good old days, when that part of the planet was a whole lot greener - and a whole lot livelier - than it has been for a long, long time.

It would appear that many of Earth's higher-latitude terrestrial ecosystems might well be able to sustain considerably greater primary productivity, as well as much larger numbers of higher trophic-level consumers, in a CO2-enriched and warmer world.

These data confirm the findings of prior satellite assessments of the vegetative transformation of Earth's northernmost collection of landscapes over the past three decades, thanks not only to global warming, but also to the aerial fertilization and water-use efficiency-enhancing effects of atmospheric CO2 enrichment.

Taken together, the results of the studies reviewed in this summary paint a picture of the planet's terrestrial vegetation that is just the opposite of what is promulgated by the world's climate alarmists. Land-based plants of the Arctic and near-Arctic regions of North America are not headed down the road of environmental degradation and toward extinction, but are thriving, thanks in large part to the ongoing rise in the atmosphere's CO2 concentration and global warming.

New SPPI paper on Ocean Acidification

Since the CO2 causes catastrophic global warming schtick hasn't worked out, many alarmists have now turned their focus onto another imaginary problem: CO2 causing "acidification" of the oceans. A new SPPI paper by Lord Monckton exposes the fallacy.

Key points:

• Doubling of atmospheric levels would only increase dissolved CO2 in the oceans by .48%
• There is no reliable evidence that ocean pH is falling
• Increased CO2 dissolution in the oceans increases calcification of shellfish and coral
• Corals evolved at a time when CO2 levels were 15 times higher than the present
• Laboratory experiments on sealife in which hydrochloric acid is added to the water (not CO2) and without the natural buffers present in the ocean is meaningless to determine effects of increased CO2 levels on sealife.

Other recommended resources on "Ocean Acidification":

Review finds CO2 fertilization has increased forest productivity and resistance to drought

A new paper from SPPI and CO2 Science reviews the scientific literature on biospheric productivity in South America and finds robust evidence that the increase in CO2 fertilization has resulted in ever-increasing forest production. In addition, plants exposed to increased CO2 have been found to lose less water to transpiration, and thus are better able to withstand drought.

For the Full Report in PDF Form, please click here.

[Illustrations, footnotes and references available in PDF version]

Excerpts:

How will the terrestrial vegetation of South America respond to global warming and atmospheric CO2 enrichment? Climate alarmists suggest there will be widespread declines in both ecosystem size and productivity. But are these predictions correct? Given the fact that over the past century the Earth has experienced what alarmists refer to as unprecedented rises in both atmospheric temperature and CO2 concentration relative to the past two thousand years and several million years, respectively, plants should already be responding to the changes in these two environmental parameters. And what has that response been? In this summary we consider this question as it applies to locations in South America.

CO2 fertilization effects strongly increased recent Net Primary Production trends in regional totals.

Such a finding is especially interesting, because for most of the past century it was believed that old-growth forests, such as those of Amazonia, should be close to dynamic equilibrium. Just the opposite, however, has been repeatedly observed by several different groups of researchers over the past two decades.

Plants exposed to elevated CO2 concentrations are likely to lose less water via transpiration.


As a result, at higher CO2 concentrations, plants can better cope under conditions of drought, thereby vastly improving their productivity and growth as opposed to conditions experienced under lower CO2.

In light of the voluminous and undeniable real-world observations reported in the studies described above, it must be acknowledged that where tropical forests have not been decimated by the direct destructive actions of man, such as the felling and burning of trees, forest productivity has been growing ever greater with the passing of time, rising hand-in-hand with the increasing CO2 content of the air; and it has been doing so in spite of all concomitant changes in atmospheric, soil, and water chemistry, as well as "dreaded" 20th-century global warming, which is claimed by climate alarmists to have been unprecedented over the past two millennia. Real-world evidence also suggests that the anthropogenic-induced increase in the air's CO2 content is primarily responsible for this beneficent state of affairs, which further suggests that if humanity will but cease its direct physical assaults upon Earth's tropical forests, there is nothing to fear about their future well-being but ill-founded fear itself.

Analysis finds the Sun explains climate change, not CO2

From the new SPPI & CO2 Science report:

"There is little need to ascribe a unique cause to late 20th-century global warming (such as elevated atmospheric CO2 concentrations), as this latest warming is merely a run-of-the-mill relative warming, sitting atop a solar-induced baseline warming that has been in progress for the past four centuries."

"In considering Qian and Lu's findings, it is important to note that, once again, no help from greenhouse gas emissions was needed to reconstruct the past thousand-year history of Earth's global mean temperature; it was sufficient to merely employ known oscillations in solar radiation variability. And as for the future, the two authors predict that "global-mean temperature will decline to a renewed cooling period in the 2030s, and then rise to a new high-temperature period in the 2060s." Given the cessation in warming observed in the surface and lower tropospheric temperature records over the past decade, it appears their prediction is well on its way to being validated. 

Clearly, there is much to recommend the overriding concept that is suggested by the data of these several papers, i.e., that the Sun rules the Earth when it comes to orchestrating major changes in the planet's climate. It is becoming ever more clear that the millennial-scale oscillation of climate that has reverberated throughout the Holocene is indeed the result of similar-scale oscillations in some aspect of solar activity. Consequently, as Mayewski et al. (2004) suggested a decade ago, "significantly more research into the potential role of solar variability is warranted, involving new assessments of potential transmission mechanisms to induce climate change and potential enhancement of natural feedbacks that may amplify the relatively weak forcing related to fluctuations in solar output." We only hope that more scientists will take note and examine the intriguing relations between our nearest star and our planet's temperature."

For the Full Report in PDF Form, please click here.

[Illustrations, footnotes and references available in PDF version]

The claim that anthropogenic greenhouse gas emissions have been responsible for the warming detected in the twentieth century is based on what Loehle (2004)[1] calls "the standard assumption in climate research, including the IPCC reports," that "over a century time interval there is not likely to be any recognizable trend to global temperatures (Risbey et al., 2000), and thus the null model for climate signal detection is a flat temperature trend with some autocorrelated noise," so that "any warming trends in excess of that expected from normal climatic variability are then assumed to be due to anthropogenic effects." If, however, there are significant underlying climate trends or cycles-or both-either known or unknown, that assumption is clearly invalid.

Review finds increased CO2 will lead to increased crop yields, even if warming resumes

A new review paper from SPPI & CO2 Science finds "future increases in the atmosphere's CO2 concentration will likely lead to increased crop growth and yield production, even in areas where reduced soil moisture availability produces significant plant water stress."

For the Full Report in PDF Form, please click here.

[Illustrations, footnotes and references available in PDF version]

Excerpts:

As the air's CO2 content continues to rise, nearly all of earth's plants will exhibit increases in photosynthesis and biomass production; but climate alarmists periodically claim that elevated concentrations of atmospheric CO2 will lead to more droughty conditions in many parts of the world and thereby significantly reduce or totally negate these CO2-induced benefits. Therefore, to help determine to what degree this claim has any validity, we here review and summarize the results of numerous CO2-enrichment studies that were designed and conducted in such a way as to reveal the various means by which atmospheric CO2 enrichment may actually help a number of important food crops to successfully cope with this potential problem of more frequent periods of less-than-optimal water availability.

If atmospheric CO2 enrichment allows plants to maintain a better water status during times of water stress, it is only logical to expect that they should exhibit greater rates of photosynthesis than plants growing in similarly-water-deficient soil in non-CO2-enriched air.

Where water availability is a prime limiting economic resource, it can be distributed more effectively under higher CO2 conditions

Average wheat yields are likely to increase by 1.2 to 2 t/ha (15-23%) by the 2050s because of a CO2-related increase in radiation use efficiency.

To briefly summarize the findings of this review of the effects of water insufficiency on the productivity of the world's major agricultural crops, the earlier optimistic conclusions of Idso and Idso (1994) are found to be well supported by the recent peer-reviewed scientific literature, which indicates that the ongoing rise in the air's CO2 content will likely lead to substantial increases in the photosynthetic rates and biomass production of the world's major agricultural crops, even in the face of the stressful conditions imposed by less-than-optimum soil moisture conditions. Therefore, future increases in the atmosphere's CO2 concentration will likely lead to increased crop growth and yield production, even in areas where reduced soil moisture availability produces significant plant water stress.

Review paper finds Medieval Warming Period was global and warmer than the present

A new review paper from SPPI and CO2 Science reviews the published literature on the Medieval Warming Period in South America and finds "(1) the Medieval Warm Period was a global phenomenon that was comprised of even warmer intervals than the warmest portion of the Current Warm Period, and that (2) the greater warmth of the Medieval Warm Period occurred when there was far less CO2 in the air than there is nowadays, which facts clearly demonstrate that the planet's current - but not unprecedented - degree of warmth need not have been CO2-induced."

For the Full Report in PDF Form, please click here.

[Illustrations, footnotes and references available in PDF version]

Excerpts:

Was there a Medieval Warm Period anywhere in addition to the area surrounding the North Atlantic Ocean, where its occurrence is uncontested? This question is of utmost importance to the ongoing global warming debate, since if there was, and if the locations where it occurred were as warm then as they are currently, there is no need to consider the temperature increase of the past century as anything other than the natural progression of the persistent millennial-scale oscillation of climate that regularly brings the earth several-hundred-year periods of modestly higher and lower temperatures that are totally independent of variations in atmospheric CO2 concentration. Hence, this question is here considered as it applies to South America, a region far removed from where the existence of the Medieval Warm Period was first recognized.

ST data indicate that the current level of warmth in that part of the world still has a long way to go before equaling the warmth experienced there a thousand and more years ago, which suggests that the region's current level of warmth is neither unprecedented nor unnatural -and therefore need not be CO2-induced - as is also the case for most of the rest of the planet.

This finding of Neukom et al. goes a long ways towards demonstrating that: (1) the Medieval Warm Period was a global phenomenon that was comprised of even warmer intervals than the warmest portion of the Current Warm Period, and that (2) the greater warmth of the Medieval Warm Period occurred when there was far less CO2 in the air than there is nowadays, which facts clearly demonstrate that the planet's current - but not unprecedented - degree of warmth need not have been CO2-induced.

New review paper finds temperature history of Antarctica argues strongly against AGW

A new review paper from SPPI and CO2 Science reviews the published scientific literature on historical temperature trends in Antarctica and concludes, "in light of the many findings of the diverse studies cited above, it is clear that the temperature history of Antarctica provides no evidence for the CO2-induced global warming hypothesis. In fact, it argues strongly against it."

For the Full Report in PDF Form, please click here.

[Illustrations, footnotes and references available in PDF version]

 Excerpts:

From the birth and death of ice ages to the decadal meanderings of modern-day weather patterns, studies of Antarctica bear witness to the fact that the atmosphere's CO2 concentration is not a major player in bringing about significant changes in earth's climate; and in what follows, the case for this proposition is presented in the form of brief reviews of pertinent studies directed, first of all, at glacial periods, then the singular Holocene, and finally the past few decades.

By the turn of the century (and millennium), the bottom of the poorly-constructed bandwagon had begun to fall apart … and a severe blow was thus dealt to the climate-alarmist community, as a major tenant of the CO2-induced global warming hypothesis was shown to be contradicted by real-world observations.

The US, British and Italian researchers say their findings indicate "warmer-than-present climate conditions" at the times and locations of the identified presence of the southern elephant seal, and that it would have been exposed to environments substantially warmer than present.

Their data also indicate that the level of this warmth … was not intense enough to drive the seals from Antarctica.

Antarctica as a whole appears to be in the midst of a cooling trend, based on the study of Watkins and Simmonds (2000), who analyzed region-wide changes in sea ice.


Reporting on trends in a number of Southern Ocean sea ice parameters over the period 1987 to 1996, they found statistically significant increases in sea ice area and total sea ice extent, as well as an increase in sea ice season length since the 1990s.

When all is said and done, therefore, the fantastic multi-meter rise in sea level predicted by Al Gore and James Hansen to occur this century appears to be pure fantasy, and even more so, in light of Monaghan and Bromwich's ultimate observation that "a widespread signal of Antarctic climate change is not obvious over the past ~50 years."

In conclusion, and in light of the many findings of the diverse studies cited above, it is clear that the temperature history of Antarctica provides no evidence for the CO2-induced global warming hypothesis. In fact, it argues strongly against it. But what if the Antarctic were to warm as a result of some natural or anthropogenic-induced change in earth's climate? What would the consequences be? 

For one thing, it would likely help to increase both the number and diversity of penguin species (Smith et al., 199927; Sun et al., 200028), and it would also tend to increase the size and number of populations of the continent's only two vascular plant species (Xiong et al., 200029). With respect to the continent's great ice sheets, there would not be much of a problem either, as not even a warming event as dramatic as 10°C is predicted to result in a net change in the East Antarctic Ice Sheet (Näslund et al., 200030), which suggests that climate-alarmist predictions of catastrophic coastal flooding due to the melting of the world's polar ice sheets are way off the mark when it comes to representing reality.

Michael Mann's hockey stick graph is the most laughable & widely discredited object in the history of science

Monckton to Mann: Forget personalities, science is about truth

Source:  Christopher Monckton, The SPPI Blog

Lord Monckton

The Editor, Richmond Times-Dispatch, August 15, 2013.

Sir,

Charles Battig did a great service to your readers by spreading truth about the now-collapsed climate scare. Michael Mann’s criticisms of him (August 5) were ill-founded. Attorney General Cuccinelli investigated Mr Mann under the Fraud Against Taxpayers Act 2000 because of what I shall delicately call the statistical peculiarities evident in Mr Mann’s “hockey stick” graph that had purported to abolish the medieval warm period and to show – falsely – that today’s quite normal global temperatures were unprecedented in 1300 years.

Mr Mann’s graph relied heavily upon the widths of tree-rings from bristlecone pines as a basis for estimating temperatures before we had thermometers, although these pines are unreliable proxies because the tree-rings widen not only when the weather is warmer but also when it is wetter and when there is more CO2 in the air. That kinda musses things up.

The Matrix 4

According to real scientists, the graph also gave extreme weighting to datasets that showed unusual 20^th-century warming at the expense of those that did not. And the program that Mr Mann created to draw the graph would have shown the 20^th century as unusually warm even if random red noise rather than real-world data were fed in. There were numerous other statistical curiosities. Mr Mann’s graph is perhaps the most laughable and widely-discredited object in the history of bad science supporting worse politics.

Most learned papers based on real-world data show that the medieval warm period was real, global, and warmer than the present. A spate of papers by computer modelers apparently confirming Mr Mann’s contrarian conclusion appeared with interesting suddenness after his paper was scientifically discredited. Many of the authors, according to an independent statistical report for the House Energy & Commerce Committee in 2006, were linked to Mr Mann by previous co-authorship. Hmmm.

Mr Battig did not criticize Mr Mann for his bad personality, though Mr Mann’s characteristically malevolent description of his opponents as “deniers” and “denialists” several times in his letter of reply would be illegal in Europe as being anti-Jewish, racialist hate-speech disrespectful of Holocaust victims. Certainly no real scientist would use such language. Mr Battig criticized Mr Mann for his flagrantly bad science, not his flagrantly bad manners. Science is not about personalities. It is about seeking truth. Mr Mann’s graph was not true. It was not science. It deserved criticism. It got it.

Besides, according to the satellites, notwithstanding record increases in CO2 concentration there has been no global warming at all for 16 years 8 months – and counting. That is 200 months without so much as a flicker of global warming. The game is up and the scare is over.

Yours faithfully,

Monckton of Brenchley

Related: 

Michael Mann, climate charlatan

There He Goes Again: Mann Claims His Hockey Stick was Given "Clean Bill of Health"

There He Goes Again: Mann Claims His Hockey Stick was Affirmed by the NAS

There He Goes Again, Version 4.0: Mann Claims His Hockey Stick was Affirmed by the NAS

There He Goes Again, Version 5.0: Mann Claims His Hockey Stick was Affirmed by the NAS

Analysis finds the Medieval Warming Period was global and unrelated to CO2

A new paper from SPPI & CO2 Science:

For the Full Report in PDF Form, please click here.

[Illustrations, footnotes and references available in PDF version]

Excerpts:

The Medieval Warm Period (MWP) was a global climatic anomaly that encompassed a few centuries on either side of AD 1000, when temperatures in many parts of the world were even warmer than they are currently. The degree of warmth and associated changes in precipitation, however, varied from region to region and from time to time; and, therefore, the MWP was manifest differently in different parts of the world. How it behaved in Russia is the subject of this Summary.

In contradiction of another of Mann et al.'s contentions, Krenke and Chernavskaya went on to unequivocally state - on the basis of the results of their comprehensive study of the relevant scientific literature - that “the Medieval Warm Period and the Little Ice Age existed globally.”

The fact that the warming that brought the world the Current Warm Period began around 1750 AD, or nearly 100 years before the modern rise in atmospheric CO2 concentration, should be evidence enough to argue that the planet's current warmth is the result of nothing more than the most recent and expected upward swing of this natural climatic oscillation.

From approximately AD 1200 to 1410, they concluded that temperatures in the region of their study were “probably higher than today,” providing yet another example of times and places when and where low-CO2 Medieval Warm Period temperatures were likely higher than high-CO2 Current Warm Period temperatures.

In conclusion, and considering the full spectrum of studies included in this Summary, it would appear that a goodly portion of the Medieval Warm Period throughout Russia was somewhat warmer than what has so far been experienced there during the Current Warm Period. And since the MWP held sway when the atmosphere's CO2 concentration was something on the order of 285 ppm, as compared to the 400 ppm of today, it would appear that the air's CO2 content has had essentially nothing to do with earth's near-surface air temperature throughout the entire Holocene, when the air's CO2 concentration at times dropped as low as 250 ppm. Other factors have clearly totally dominated.

Review paper finds European climate change due to the Sun, not CO2

A new SPPI & CO2 Science review paper entitled Solar Influence on European Temperatures finds extensive evidence that solar activity has dominated European climate change of the past 2 millennia  which "suggests that there is little reason to attribute 20th-century global warming to the concomitant increase in the air's CO2 content. Natural variability appears quite capable of explaining it all. In conclusion, paleoclimatic studies from Europe provide more evidence for the global reality of solar-induced temperature oscillations pervading both glacial and interglacial periods, which oscillations are looking more and more likely as the primary forcing agent responsible for driving temperature change during the Current Warm Period. The concurrent historical increase in the air's CO2 content, on the other hand, is likely little more than a bit player."

Excerpt:
"In yet another refutation of the theory of CO2-induced global warming, Mangini et al. found "a high correlation between δ18O and δ14C, that reflects the amount of radiocarbon in the upper atmosphere," and they note that this correlation "suggests that solar variability was a major driver of climate in Central Europe during the past 2 millennia." In this regard, they report that "the maxima of δ18O coincide with solar minima (Dalton, Maunder, Sporer, Wolf, as well as with minima at around AD 700, 500 and 300)," and that "the coldest period between 1688 and 1698 coincided with the Maunder Minimum." Also, in a linear-model analysis of the percent of variance of their full temperature reconstruction that is individually explained by solar and CO2 forcing, they found that the impact of the Sun was fully 279 times greater than that of the air's CO2 concentration, noting that "the flat evolution of CO2 during the first 19 centuries yields almost vanishing correlation coefficients with the temperature reconstructions."

For the Full Report in PDF Form, please click here.

[Illustrations, footnotes and references available in PDF version]

We begin this review of the Sun's influence on European temperatures with the study of Holzhauser et al. (2005)[1], who presented high-resolution records of variations in glacier size in the Swiss Alps together with lake-level fluctuations in the Jura mountains, the northern French Pre-Alps, and the Swiss Plateau in developing a 3,500-year climate history of west-central Europe, starting with an in-depth analysis of the Great Aletsch glacier, which is the largest of all glaciers located in the European Alps.