plant and animal response to global warming

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SPPI ORIGINAL P APER ♦ May 13, 2010

Delivered at the4th International Conference

on Climate Change

““SScciieennccee aanndd AAllaarrmmiissmm””

May 16-18, 2010Chicago, Illinois

PLANT AND A NIMAL R ESPONSE

TO GLOBAL W ARMING A PRESENTATION BY R OBERT FERGUSON, PRESIDENT

SCIENCE AND PUBLIC POLICY INSTITUTE



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Slide 1

One of the grandest of all catastrophes predicted by climate alarmists to occur as a result of CO2-induced global warming is that manyplant and animal species will not be able to migrate poleward in latitude or upward in altitude fast enough to remain within thetemperature regimes suitable for their continued existence, and, therefore, many of them will likely be driven to extinction.

This famous, or perhaps infamous, claim has pervaded the thinking of the world’s climate alarmists ever since it was first suggested,and it figures prominently in the doom-and-gloom prognostications of Al Gore, James Hansen and others like them.



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Slide 2

It has also entered into the scientific assessments of the IPCC, where in their latest report it was projected that "globally about 20% to30% of species ... will be at increasingly high risk of extinction" by the year 2100 due to CO2-induced global warming. But are suchconcerns correct?

In an effort to find out, last year the Science and Public Policy Institute commissioned a landmark study that thoroughly examined theglobal warming/extinction hypothesis.



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Slide 3

After analyzing nearly 300 peer-reviewed scientific journal articles, the results were presented in a book entitled CO2, Global Warming

and Species Extinctions: Prospects for the Future. Over the next several minutes I will briefly report to you only some of those findings,which I can happily add do not suggest that significant portions of Earth's flora and fauna will be driven to extinction as a result of themodern rise in atmospheric CO2 emissions.



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Slide 4

At first blush, the extinction hypothesisseems reasonable enough, all else being

equal. But “all else” is almost always not equal when something changes in the realworld; and the case in point is noexception. Accompanying the increase inair temperature over the past century, for example -- and accompanying anytemperature increase that may yet occur in this century -- there was, and will be, aconcomitant increase in the atmosphere’sCO2 concentration; and the physiologicaleffects of this phenomenon -- which arealmost always totally ignored byproponents of the extinction hypothesis --have some critically importantconsequences that dramatically alter theconclusions of the world's climatealarmists. In fact, these consequencesactually refute their conclusions.

The key fact climate alarmists typically ignore is that plants in a CO2-enriched atmosphere generally prefer warmer temperatures thanthose they prefer when exposed to air of a lower CO2 concentration. Many experiments convincingly demonstrate, in this regard,that a doubling of the air’s CO2 concentration typically boosts the optimum temperature for plant photosynthesis by several degreesCentigrade, and that it raises the temperature at which plants experience heat-induced death by about the same amount, asillustrated in this next set of slides depicting net photosynthetic rates of bigtooth aspen leaves at different temperatures anddifferent CO2 concentrations.



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Slide 5

As can be seen here by the red circle, at 10°C, elevated CO2 has essentially no effect on net photosynthesis in this particular species.



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Slide 6

At 25°C, however, where the net photosynthetic rate of the leaves exposed to 325 ppm CO2 is maximal, the extra CO2 of this studyboosts the net photosynthetic rate of the foliage by nearly 90%;



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Slide 7

and at 37°C, where the net photosynthetic rate of the leaves exposed to 1935 ppm CO2 is maximal, the extra CO2 boosts the netphotosynthetic rate of the foliage by a whopping 475%.



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Slide 8

In addition, it is readily seenthat the extra CO2 increases

the optimum temperaturefor net photosynthesis inthis species by about 12°C:from 25°C in air of 325 ppmCO2 to 37°C in air of 1935ppm CO2.

In viewing the warm-temperature projections ofthe two relationships, it can

also be seen that thetransition from positive tonegative net photosynthesis– which denotes a changefrom life-sustaining to life-depleting conditions – likelyoccurs somewhere in thevicinity of 38°C in air of 325ppm CO2 but somewhere in

the vicinity of 50°C in air of1935 ppm CO2. Hence, notonly was the optimumtemperature for the growth

of bigtooth aspen greatly increased by the extra CO2 of this experiment, so too was the temperature above which life cannot besustained increased by the elevated CO2, and by about the same amount, that is 12°C. And, of course, one must also remember thatextra CO2 in the air nearly always leads to greater rates of plant photosynthesis and biomass production, as well as a heightenedability to successfully deal with most naturally-occurring environmental stresses and resource limitations.



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Slide 9

As a result of each of these CO2-induced changes in basic physiological behavior, Earth’s plants will likely not be eliminated from largeportions of their current natural habitats near the heat-limited boundaries of their ranges in a CO2-enriched world of the future -- evenif temperatures were to rise as high as is unrealistically predicted by climate alarmists -- because most types of vegetation, with thehelp of the extra CO2, would be able to tolerate much warmer living conditions than they do currently.



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Slide 10

Simultaneously, as shown in this hypothetical example, at the cold-limited boundaries of their present ranges, they would have anopportunity to expand into areas that warmed and thereby invited their colonization. Hence, with stable heat-limited boundaries andpoleward- and upward-moving cold-limited boundaries, Earth’s plants in a CO2-enriched and warmer world would actually experienceincreases in the sizes of the territories they could successfully inhabit, making them not more likely but less likely to experienceextinction.



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Slide 11

This same type of rangeoverlapping will also likely apply to

many of the world's animals thatrely upon these range-expandingplants for their food and habitat.Therefore, the end result of theseseveral natural processes is afuture in which there will likely be agreat CO2-induced proliferation ofregional biodiversity, as opposed toextinctions of species globally; andthere is much evidence from the

peer-reviewed scientific literatureto support such an outcome.

Highlighting a couple of examplesthat demonstrate the reality of thisphenomenon, in 2003, Walther et

al. (2005) resurveyed the floristiccomposition of the uppermost tenmeters of ten mountain summits in

the Swiss Alps, applying the samemethodology used in earlier surveys of the same mountain tops

by previous researchers who conducted studies in 1905 and 1985. Consequently, the analysis covered the bulk of the Little Ice Age-to-Current Warm Period transition (1905-2003), the last portion of which (1985-2003) is claimed by climate alarmists to have experienceda warming that was unprecedented over the past two millennia in terms of both the rate of temperature rise and the level to which thetemperature rose. So what did they find?



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Slide 12

The three researchers’ work revealed there was an 86% increase in species numbers from 1905 to 1985, and that by 2003 speciesnumbers had more than doubled to 138% more than what there were in 1905; and they were 26% higher than what they were in 1985.Put another way, Walther et al. state that “the rate of change in species richness (3.7 species per decade) was significantly greater inthe later period compared to the [1985] resurvey (1.3 species per decade).”



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Slide 13

Nevertheless, they say “the observed increase in species numbers does not entail the replacement of high alpine specialists by species

from lower altitudes [italics added], but rather has led to an enrichment [italics added] of the overall summit plant diversity.”Consequently, in spite of the apparent reasonableness of the global warming extinction hypothesis, whereby high-altitude species areexpected to be “squeezed out of existence” -- or “pushed off the planet,” as NASA’s James Hansen describes it -- by other speciesmigrating upwards from lower altitudes to escape the increasing stress of rising temperatures, Walther et al. could find no sign of thisdire predicted consequence over an entire century of supposedly unprecedented warming in the Swiss Alps.



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Slide 14

Turning to an example fromthe animal kingdom, using data

from the Breeding Bird Atlas ofLake Constance, which bordersGermany, Switzerland andAustria, Lemoine et al. (2007)analyzed the impact of land-use and climate changes onthe abundance of CentralEuropean birds between theperiods 1980-1981 and 1990-1992, and between 1990-1992

and 2000-2002. This workrevealed, in their words, that“the total number of [bird]species in the Lake Constanceregion increased from 141species in 1980 to 146 speciesin 1990 and to 154 species in2000,” while “winter temperatures increased by

2.71°C and spring temperaturesincreased by 2.12°C over the 23years from the first to the lastcensus.” These and other data

thus led them to conclude that “increases in temperature appear to have allowed increases in abundance of species whose rangecenters were located in southern Europe and that may have been limited by low winter or spring temperature.” In addition, theyreport that “the impact of climate change on bird populations increased in importance between 1990 and 2000 and is now more

significant than any other tested factor [italics added],” which is a very important finding because the warming has tremendouslybenefited European birds and helped to buffer them against extinction.



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Slide 15

In another example, this time from North America, White and Kerr (2006), as they describe it, "report butterfly species' range shiftsacross Canada between 1900 and 1990 and develop spatially explicit tests of the degree to which observed shifts result from climateor human population density," the latter of which factors they describe as "a reasonable proxy for land use change," within whichbroad category they include such things as "habitat loss, pesticide use, and habitat fragmentation," all of which anthropogenic-drivenfactors have been tied to declines of various butterfly species. In addition, they say that to their knowledge, "this is the broadest scale,longest term dataset yet assembled to quantify global change impacts on patterns of species richness."



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Slide 16

This exercise led White and Kerr to discover that butterfly species richness "generally increased over the study period, a result ofrange expansion among the study species," and they further found that this increase "from the early to late part of the 20th centurywas positively correlated with temperature change," which had to have been the cause of the change, for they also found that speciesrichness was "negatively correlated with human population density change." Contrary to the doom-and-gloom prognostications ofthe world's climate alarmists, therefore, the supposedly unprecedented -- and dreaded -- global warming of the 20th century has beennothing but beneficial for the butterfly species that inhabit Canada, as their ranges have expanded and greater numbers of species arenow being encountered in most areas of the country.



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Slide 17

Other research papers discussedin the book highlight another reason why the extinctionpredictions are unlikely to occur:evolution. Research into theevolution of animals on shorttimescales (decades) is still in itsinfancy. Nevertheless, the bookdetails promising new researchthat suggests plants and animalscan evolve over much shorter periods of time than was

previously thought possible,effectively coping with climaticstress, be it of natural or anthropogenic origin. For example, research has notedthat populations of the frog Rana

sylvatica have undergonelocalized evolution in thermaltolerance, temperature-specificdevelopment rate, and thermalpreference in less than 40 years(Skelly et al. 2007) and laboratory

studies of insects show that thermal tolerance can change markedly after as few as 10 generations (Good, 1993). In addition, studiesof microevolution in plants show substantial trait evolution in response to climate manipulations (Bone and Farres, 2001), leading oneresearch group (Skelly et al., 2007) to claim that "collectively, these findings show that genetic variation for traits related to thermalperformance is common and evolutionary response to changing climate has been the typical finding in experimental andobservational studies (Hendry and Kinnison, 1999; Kinnison and Hendry, 2001)."



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Slide 18

Although evolution will obviously be slower in the cases of large mammals and long-lived trees, where long generation times are the

norm, the case for rapid evolutionary responses among many other species has grown much stronger. As a result, Skelly et al. haveconcluded that "on the basis of the present knowledge of genetic variation in performance traits and species' capacity for evolutionary response, it can be concluded that evolutionary change will often occur concomitantly with changes in climate [italics andbold added] as well as [with] other environmental changes (e.g., Grant and Grant, 2002; Stockwell et al., 2003; Balanya et al., 2006;Jump et al., 2006; Pelletier et al., 2007)." Thus, it would appear that many of Earth's organisms have the capacity to rapidly evolve inways to help them successfully cope with the future changes and degrees of warming that are predicted to result from projectedbusiness-as-usual anthropogenic greenhouse-gas emissions.



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Slide 19

In closing, I would like to mentionone other critical point ofdiscussion in the book. Inaddition to staving off warming-induced extinctions, the case ismade that the ongoing rise in theair’s CO2 content may be our last,best hope for avoiding a seriousnon-climatic catastrophe that acadre of particularly insightfulresearchers has found to belooming ominously on the

horizon, but about which muchless is typically said or written,although it represents a morerealistic, more immediate, andmore dangerous threat to thewell-being of man and naturealike than that of speculative CO2-induced global warming. Thispotential catastrophe derivesfrom the fact that humans are oncourse to completely annihilatefully two-thirds of the ten millionor so other species with which

we share the planet within a mere hundred years, simply by taking their land. This unfathomable consequence will occur, simplybecause we will need more land to produce what is required to sustain us and we will take the needed land from nature to keepourselves alive. Yet, in an ironic twist of fate, what many people believe to be the cause of global warming, i.e., anthropogenic CO2 emissions, may actually be the most powerful force for preserving land for nature over which we have any degree of control. So howis it to be done?



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Slide 20

Briefly, Tilman et al. (2002) suggested a strategy for slowing the taking of wild nature that is built around three essential tasks: (1)increasing crop yield per unit of land area, (2) increasing crop yield per unit of nutrients applied, and (3) increasing crop yield per unitof water used, all three of which tasks are brought about naturally via the manifold benefits of atmospheric CO2 enrichment.



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Slide 21

Thus, as the air’s CO2 content continues torise, so too will the land use efficiency of theplanet rise right along with it. In addition,atmospheric CO2 enrichment typicallyincreases plant nutrient use efficiency andplant water use efficiency. Consequently,with respect to all three of the major needsnoted by Tilman et al. (2002), increases inthe air’s CO2 content pay huge dividends,helping to increase agricultural outputwithout the taking of new lands fromnature.

That certain forces continue to resist thisreality is truly incredible. More CO2 meanslife for the planet; less CO2 means death ...and not just the death of individuals, but thedeath of entire species. And to allow, nay, tocause the extinction of untold millions ofunique and irreplaceable plants and animalshas got to rank close to the top of all

conceivable immoralities.

Considered in this light, we humans, asstewards of the Earth, have got to get our science and priorities straight. We have gotto do all that we can to preserve nature byhelping to feed humanity; and to do so

successfully, we have got to let the air’s CO2 content continue to rise. Any policies that stand in the way of that objective, therefore,are not only immoral, they are obscene.



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Slide 22

Thank you.



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plant and animal response to global warming

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