Foute hockeysticks en het versterkt broeikaseffect.

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Weer een bewijs dat het broeikas effect niks met menselijke activiteiten te maken heeft....... maar alles met smerige politieke spelletjes.

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Op donderdag 27 januari 2005 08:46 schreef pseudo het volgende:
http://www.fd.nl/ShowKrantArtikel.asp?KrantArtikelId=498048

Horrorscenario klimaat berust op fout

Van Dorland benadrukt wel dat het onderzoek van McIntyre en McKitrick niets zegt over het toekomstige klimaat. 'De opwarming van de aarde blijft een bedreiging.'



Weer een bewijs dat het broeikas effect niks met menselijke activiteiten te maken heeft....... maar alles met smerige politieke spelletjes.

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Op donderdag 27 januari 2005 09:16 schreef Muizig het volgende:

[..]

Lees eerst je eigen stuk eens voordat je er conclusies uittrekt

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Op donderdag 27 januari 2005 08:59 schreef smash789 het volgende:
Het is juist intelligent dat ie niet mee doet, en enorm dom en naief van de andere landen die er wél aan meedoen. Maar ja, hoe vertel je dat aan die GroenLinks Bush-bashers?

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Op donderdag 27 januari 2005 09:16 schreef Muizig het volgende:

Lees eerst je eigen stuk eens voordat je er conclusies uittrekt

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Op donderdag 27 januari 2005 09:24 schreef pseudo het volgende:

[..]
Maar wij tonen aan dat het in de 15de eeuw net zo warm was als nu.'

In de 15e eeuw was er nog geen industrie en vervuilende auto's........

Dankzij het frauduleuze IPCC rapport worden de burgers gedwongen om nog meer belasting te betalen.

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Bewijs achter Kyoto deugt niet

De grafiek die laat zien dat het nu warmer op aarde is dan de afgelopen duizend jaar, is een statistisch verzinsel. Dat stellen de Canadese wetenschappers Stephen McIntyre en Ross McKitrick. Een verbijsterende conclusie want de betreffende grafiek is een van de belangrijkste pijlers onder het Kyoto-protocol. De Canadezen publiceren hun resultaten in het gezaghebbende tijdschrift Geophysical Research Letters. In Natuurwetenschap & Techniek van deze maand doen ze hun bevindingen uitgebreid uit de doeken.

Press interested in our article on the climate controversy in our February issue, can reach our editors at redactie@natutech.nl



McIntyre en McKitrick hebben gepoogd een beroemde studie van de Amerikanen Michael Mann, Raymond Bradley en Malcolm Hughes uit 1998 te reproduceren. Mann publiceerde toen wat later de hockeystick-grafiek is gaan heten, een temperatuurreconstructie van het noordelijk halfrond over de afgelopen duizend jaar.
Vanaf het jaar 1000 neemt de temperatuur geleidelijk af om vervolgens vanaf 1900 sterk te stijgen. De suggestie is enorm: het wereldwijde klimaat zat in een dalende trend maar onder invloed van de mens is die trend wreed verstoord en omgezet in een sterke stijging.
De hockeystick-grafiek kreeg in 2001 een prominente plek in de Summary for Policymakers van het laatste rapport van het Intergovernmental Panel on Climate Change (IPCC). Op deze samenvatting van het IPCC baseren overheden hun klimaatbeleid en dus hun beslissing om al dan niet aan Kyoto mee te doen.
De grafiek van Mann, Bradley en Hughes is voornamelijk gebaseerd op klimaatindicatoren zoals jaarringen van bomen en ijskernen. McIntyre en McKitrick ontdekten dat Mann, Bradley en Hughes (al dan niet bewust) een cruciale fout gemaakt hebben bij het bewerken van hun data. Die fout heeft tot gevolg dat bomen die een sterke stijging van de temperatuur laten zien in de 20e eeuw aanzienlijk zwaarder meetellen in de statistische analyse dan bomen waarvoor dit niet geldt. De statistische methode van Mann stuurt dus aan op de hockeystick-grafiek!
Als McIntyre en McKitrick de data van Mann op een correcte manier bewerken krijgen ze een 15e eeuw die warmer is dan het eind van de 20e eeuw. Veel conclusies trekken de Canadezen hier echter niet uit, omdat ze grote twijfels hebben over de betrouwbaarheid van de data van Mann.
Het 'recherchewerk' van McIntyre en McKitrick, die zelf geen klimaatonderzoekers zijn, laat zien hoe gepolitiseerd het klimaatonderzoek op dit moment is. Klimaatonderzoeker Rob van Dorland van het KNMI, die tevens lead author is bij het IPCC, erkent dat het imago van het IPCC hiermee een enorme deuk oploopt.

Lees het volledige artikel in Natuurwetenschap & Techniek van februari. Het blad ligt vanaf zaterdag 29 januari in de kiosk.

Wij hebben de zwaarste beschuldigingen aan Michael Mann voorgelegd:

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Onze vragen aan Mann

Dear dr Mann, dr Bradley and dr Hughes,



I am working on a long (10 page) cover story on the Hockey Stick for Natuurwetenschap & Techniek, a Dutch monthly science magazine which is comparable with Scientific American.



I have made a detailed analysis of MBH98 and also of the work of McIntyre & McKitrick (MM) and Von Storch & Zorita. I also studied your latest comment on MM04 on the weblog www.realclimate.org (dd 4 December)



In my opinion there are some issues still open on which I would like to hear your comment. This could be done by email, but I would prefer to call one of you and discuss the topic by phone.



Here are the issues:

1) How do you explain the existence of the directory BACKTO_1400-CENSORED on Mann's ftp-server? MM show that it contains the results of the calculation of the NOAMER PC's without using the bristlecone pine series, giving a higher NH temperature in the 15th century.

2) There is a severe debate between you and MM about the skill of the calculation. You claim a high RE-statistic. MM show that their simulated hockey sticks also give a high RE-statistic but a very low R^2 statistic. In MBH98 you didn't calculate the R^2 statistic, but in Mann and Jones (2003) you did. I asked Eduardo Zorita questions about this and he said he would calculate both. Why didn't you calculate the R^2 in MBH98?

3) On the weblog www.realclimate.org you state that MM should use 5 PC's in the NOAMER-network if they use conventional PCA. Especially the PC4 is important while it accounts for the bristlecone pine series. This means that the overall result in MBH98 depends on a single PC4. This is in contrary with the claimed robustness of the MBH98 method. Do you agree now that the robustness of MBH98 is lower than originally claimed?



I am looking forward to discuss these issues with one of you. If for time or other reasons you're not able to respond to this email before Friday, January 7, could you please give me a short reply.



Yours sincerely,

Marcel Crok

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Dear Mr. Crok,

Below are some responses to your questions. Unfortunately, I will be unable to reply in any more detail for more than another week due to surgery I am having (and post-surgery recovery), so you should direct further inquiries to my colleagues Bradley and Hughes, as well as the other scientists I mention below.

I hope you are not fooled by any of the "myths" about the hockey stick that are perpetuated by contrarians, right-wing think tanks, and fossil fuel industry disinformation. These myths are each dispelled here.

http://www.realclimate.org/index.php?p=11

Of particular relevant here is "myth #1" (that the "hockey stick" depends only on Mann et al--more than a dozen other estimates from proxy data and model simulations get essentially the same result (i.e., the results agree within the estimated uncertainties). See:

http://www.realclimate.org/index.php?p=7#figures

I must begin by emphasizing that McIntyre and McKitrick are not taken seriously in the scientific community. Neither are scientists, and one (McKitrick) is prone to publishing entirely invalid results apparently without apology (see below). "New Scientist" considered running an article (by David Paterson) on the MM claims. The editor decided not to run an article, concluding that their claims were suspicious and spurious after interviews with numerous experts and after it was revealed that they had suspiciously close ties with the fossil fuel/energy industry. See e.g.:
http://www.environmentaldefense.org/article.cfm?contentid=3804&CFID=21084385&CFTOKEN=29888831
You can see what USA Today science report Dan Vergano had to say about MM here:
http://www.usatoday.com/w(...)warming-debate_x.htm


I therefore hope that you will treat their claims with appropriate suspicion, and I that hope you will solicit comments from paleoclimate experts such as Phil Jones, Keith Briffa, Jonathan Overpeck, and Tom Crowley, and not rely upon comments from individuals who have little expertise in this area.

You should also discuss with Caspar Ammann and Gene Wahl of NCAR (ammann@ucar.edu, wahle@alfred.edu). They have independently discredited (paper in press, I believe) McIntyre and McKitrick. They independently reproduce the results of MBH98, and reproduce the skill in these results. They also show that the results of McIntyre and McKitrick can only be reproduced through a censoring of the dataset.

In summary. please keep in mind that McIntyre and MckItrick (1) never published their results in a peer-reviewed scientific journal ("Energy and Environment" is not considered a scientific journal, but a "social science" journal), (2) The claims, which you repeat below, were REJECTED by Nature because the reviewers and editors did not believe they had made their case, and (3) There are now 2 peer-reviewed articles discrediting MM, one that is in press:

Rutherford, S., Mann, M.E., Osborn, T.J., Bradley, R.S., Briffa, K.R., Hughes, M.K., Jones, P.D., Proxy-based Northern Hemisphere Surface Temperature Reconstructions: Sensitivity to Methodology, Predictor Network, Target Season and Target Domain, Journal of Climate, in press (2005).

and another by Ammann and Wahl (whom you should contact for more information, as mentioned above).

Replies to your specific inquiries provided below:

Best regards,

Mike Mann

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Global warming is 'twice as bad as previously thought'
By Steve Connor, Science Editor
27 January 2005


Global warming might be twice as catastrophic as previously thought, flooding settlements on the British coast and turning the interior into an unrecognisable tropical landscape, the world's biggest study of climate change shows.

Researchers from some of Britain's leading universities used computer modelling to predict that under the "worst-case" scenario, London would be under water and winters banished to history as average temperatures in the UK soar up to 20C higher than at present.

Globally, average temperatures could reach 11C greater than today, double the rise predicted by the Intergovernmental Panel on Climate Change, the international body set up to investigate global warming. Such high temperatures would melt most of the polar icecaps and mountain glaciers, raising sea levels by more than 20ft. A report this week in The Independent predicted a 2C temperature rise would lead to irreversible changes in the climate.

The new study, in the journal Nature, was done using the spare computing time of 95,000 people from 150 countries who downloaded from the internet the global climate model of the Met Office's Hadley Centre for Climate Prediction and Research. The program, run as a screensaver, simulated what would happen if carbon dioxide levels in the atmosphere were double those of the 18th century, before the Industrial Revolution, the situation predicted by the middle of this century.

[...]

Myles Allen, of Oxford University, said: "The danger zone is not something we're going to reach in the middle of the century; we're in it now." Each of the hottest 15 years on record have been since 1980

hele artikel: Independent News

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Nu kan het nooit kwaat..

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Op donderdag 27 januari 2005 08:59 schreef smash789 het volgende:
En mensen maar zeiken dat Bush niet mee doet aan het Kyoto-protocol.
Het is juist intelligent dat ie niet mee doet, en enorm dom en naief van de andere landen die er wél aan meedoen. Maar ja, hoe vertel je dat aan die GroenLinks Bush-bashers?

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Op vrijdag 28 januari 2005 16:31 schreef -Pepe- het volgende:
Kennelijk worden deze gasten niet echt serieus genomen in de wetenschappelijke wereld

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Op vrijdag 11 februari 2005 14:48 schreef PJORourke het volgende:

[..]

Dat werd Copernicus ook niet.

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Op donderdag 17 februari 2005 04:14 schreef DiegoArmandoMaradona het volgende:
Er was een tijd dat wetenschappers dat alle wetenschappers er ook heilig van overtuigt waren dat de aarde plat was.

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Op woensdag 2 februari 2005 11:22 schreef Herdenking het volgende:
vind de zogenaamde bewijzen tegen het versterkte broeikaseffect nog altijd veel te mager.

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Op donderdag 17 februari 2005 16:39 schreef MeneerGiraffe het volgende:

[..]

De statistische bewerkingen van het onderzoek van Mann, en andere klimaatonderzoekers worden terecht de grond in gestampt. En dat vind jij mager?

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Op donderdag 17 februari 2005 04:14 schreef DiegoArmandoMaradona het volgende:
Er was een tijd dat wetenschappers dat alle wetenschappers er ook heilig van overtuigt waren dat de aarde plat was.

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Op donderdag 17 februari 2005 16:39 schreef MeneerGiraffe het volgende:

[..]

De statistische bewerkingen van het onderzoek van Mann, en andere klimaatonderzoekers worden terecht de grond in gestampt. En dat vind jij mager?

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Ecologist’s "Declaration on Climate Change" Lacks Scientific Credibility

Dr. Keith E. Idso, Vice President
Center for the Study of Carbon Dioxide and Global Change
The Ecologist is an English magazine that is popular amongst the environmental movement on both sides of the Atlantic Ocean. It is funded by Teddy Goldsmith, brother of the late Sir James Goldsmith, and has a readership of approximately 14,000 people.

A "Declaration on Climate Change," which was recently published in the Ecologist, states, among other things, that in order to avoid catastrophic climate change, governments must implement crash programs leading to a near total phase-out of fossil fuel use within the next 50 years. Such measures, the declaration suggests, would return the concentration of atmospheric carbon dioxide back to 1990 levels, thereby holding rising temperatures and extreme weather events in check and protecting the world’s food production systems from the ravages of droughts, floods, heat waves, and insect pests.

How easy it is to speak of disaster and apocalypse. The words roll off the tongue with little effort and even less forethought. And that’s why talk is cheap. But evidence, now that’s something else. It, and it alone, is what all calls to action should be based upon; anything else is but political prose or positioned propaganda, providing an illusion of reality but never revealing its true nature. In light of this fact, the Greening Earth Society asked us to determine if there is any hard evidence to support the claims of the Ecologist. So let’s have a look at their Declaration – which can be found in the March issue of their magazine and on the Internet at http://ecolu-info.unige.ch/archives/envcee99/0070.html – and see how well it stacks up against reality as described in the peer-reviewed scientific literature.

THE ECOLOGIST’S DECLARATION ON CLIMATE CHANGE

We, the undersigned, call upon the world’s political and corporate leaders to take immediate action to prevent seriously disruptive climate change.

Evidence of human impact upon the earth’s climate is now irrefutable. We have emitted enough greenhouse gases into the atmosphere to commit the climate to change. If we carry on as we are, we can expect a rapidly worsening situation that - because of the long life of emissions in the atmosphere - will continue for centuries to come. Within a global trend of rising temperatures that could reach levels in the next century that our species has never previously experienced, our climate will become more and more unstable, marked by extreme and unseasonal weather.

Such climatic destabilization will have dire consequences for every part of the world, every sector of society and every aspect of our lives. Our health and food supplies will be affected dramatically by increased droughts, heat waves and the spread of disease-bearing insects and pests in response to rising temperatures. Agricultural land and our towns and cities will also suffer substantial damage from rising sea levels, and increased flooding and violent storms, with huge costs for industry and ordinary people as their homes and livelihoods are destroyed. The scientists of the UN’s Inter-governmental Panel on Climate Change predict that millions of people worldwide will die and millions of others will become environmental refugees as a result.

The effects of climate change are being felt even now. Global temperatures are rising at a rate faster than for 10,000 years, with the 12 hottest years in recorded history occurring since 1980. There has also been a sharp rise in extreme weather events, with a significant increase in the frequency and intensity of hurricanes, tornadoes, large floods and heat waves in the last 20 years that have left a trail of devastation to infrastructure and agriculture in their wake.

The extent of climatic destabilization is likely to be even more severe than previously thought if greenhouse gas emissions continue to rise unchecked. As warming increases, vital natural processes upon which we depend to absorb or contain three-quarters of our greenhouse gas emissions - such as the carbon dioxide-absorbing function of the world’s forests and oceans – would weaken and even cease to operate. Instead of being net sinks, they will become net sources of greenhouse gases.

Hence, if emissions continue to rise unchecked, we risk releasing billions of tonnes of carbon into the atmosphere as rising temperatures trigger a huge die-back of trees, causing billions of acres of South American rainforest to turn into desert before 2050, the UK Met Office’s Hadley Centre predicts. If this and other positive feedbacks occur - and they could well do so within the next few decades - we could find ourselves in a situation of catastrophic, runaway climatic destabilization.

Yet the political and corporate response to this problem has been grossly inadequate. To stabilize greenhouse gas concentrations at non-catastrophic levels, the UN’s Inter-governmental Panel on Climate Change stated in 1990 that greenhouse gas emissions from human sources would have to be reduced immediately by at least 60 percent below 1990 levels. At Kyoto, however, developed countries agreed to a cut of just 5.2 percent, to be achieved between 2008 and 2012. Worse, the US Congress has refused to ratify the US’s Kyoto commitment. Even if the Kyoto targets were met, given that developing countries are under no obligation to prevent their emissions from continuing to increase, global emissions will rise to 30 percent above 1990 levels by 2010.

We deplore the lack of serious political action to address this issue and we deplore attempts by many large corporations to block meaningful change. For short-term gain, they seem willing to jeopardize the welfare, indeed survival, of a large part of humanity.

If catastrophic climate change is to be avoided, we call upon our governments to take the following action without delay:

Accept the goal of reducing carbon dioxide concentrations in the atmosphere to 1990 levels - around 350 parts per million by volume (ppmv), whilst never exceeding 400 ppmv. A higher concentration (including that proposed by the EU of 550 ppmv –almost twice the pre-industrial level) would involve straying into a danger zone of catastrophic climatic instability.

To achieve this goal, a target of 30 years to have cut CO2 emissions by 70-80 percent below 1990 levels, and 50 years for a near total phase-out of fossil fuels should be adopted. This is the very minimum that the current crisis demands. While it may be challenging for many countries, it is the political will to implement policy options, which is the biggest challenge, not the technological one.

Implement nothing less than a crash program to meet these targets. Measures should be put in place to significantly reduce energy use. Our remaining energy requirements should be met by a combination of existing renewable energy technologies – quite feasible if invested in sufficiently and produced on a large enough scale.

Transfer all public subsidies and encourage the transfer of private investment away from supporting fossil fuels and cars towards supporting ecologically sustainable renewables and public transport. This applies in equal measure to loans and investments to developing countries from the industrialized world and the international financial institutions. It should be recognized that in developing countries, where dependence upon fossil fuels is less, it will be far easier to turn rapidly towards a renewable energy path. Everything should be done, therefore, to enable this.

Change taxation systems to reflect the need to discourage the use of fossil fuels and cars.

End the exploration and development of new oil, coal, and gas reserves immediately. To assure this, a protocol should be established under the auspices of the United Nations Framework Convention on Climate Change (UNFCCC), to coordinate the phasing out of fossil fuel production worldwide, based on a model such as the Petroleum Conservation Protocol (published by the Centre for Global Energy Studies).

Set in place a far more effective, inclusive and hence equitable international political mechanism to curb the consumption of fossil fuels in all countries. The only realistic means proposed so far of achieving this is a formal global program of "Contraction and Convergence," as advocated by GLOBE International (the Global Legislators Organization for a Balanced Environment) and by an increasing number of governments in Europe, Africa and the majority of southern countries in the so-called Group of 77 and China.

Recognize that the avoidance of serious climate change cannot succeed without the protection of the planet’s natural sinks.

Hence, take immediate action to stop the continued destruction of the world’s remaining forests, particularly tropical rainforests – critical for the stability of global climate. At the international level, legally binding forest protection must be negotiated, even if this requires the provision of compensation to those countries that possess the principal standing forests. In developed countries, consumption of wood and wood-derived paper will have to be reduced by two-thirds. Measures should also be put in place to ensure massive reforestation, while avoiding monoculture plantations of fast growing exotics where possible.

Take immediate action to eliminate all ozone-depleting chemicals - responsible for a hole in the ozone layer that in 1998 was larger than ever – and that are still being produced despite the Montreal Protocol. Also, make the removal of CFCs from all appliances prior to disposal a legal requirement. Unless this is achieved, the phytoplankton in the oceans, upon which we depend to absorb carbon dioxide, will continue to be destroyed by increasing ultraviolet radiation.

Transfer all public subsidies away from supporting industrial agriculture, which is largely responsible for the unrelenting destruction of our agricultural soils - another important sink for carbon dioxide – and for substantial emissions of carbon dioxide, nitrous oxide and methane. Instead, a rapid transition to low impact, ecologically based organic farming for local consumption should be promoted.

Reverse the current subordination of ecological and social imperatives to the short-term interests of corporations and investors and the maximization of world trade. Large-scale global trade massively increases the distance goods are transported, resulting in more greenhouse gas emissions, whilst simultaneously exerting powerful deregulatory pressures that prohibit governments from raising environmental standards. Hence, the provision of subsidies and the signing of treaties that increase this trend should cease. A change of direction towards the nurturing of a network of more self-sustaining, local economies and an end to undemocratic corporate influence on the political process is essential.

Whilst the changes that are required may seem great, we are not calling up on people to make huge sacrifices. All of the measures that we have outlined, essential to prevent dangerous climatic disruption, are needed whether or not our climate were in danger, as they will help solve many of the other major problems that confront us today, such as unemployment, ill health and threats to peace. Implementing these measures will ensure that -

more jobs are created and income saved from the development of new renewable technologies and from the re-emergence of strong local economies;

a vast improvement in our health takes place with clean air in our cities;

greater world security is achieved as tensions over the control of oil in the Middle East and elsewhere are diminished;

the planet’s rainforests, the lungs of the world and home to 50-80 percent of animal and plant species, are saved from destruction;

greater food security and better health is attained with ecologically sustainable methods of agriculture.

Whilst avoiding the worst impacts of climate change, our entire quality of life will also improve. The benefits of such action are clearly huge and the costs low when compared to the massive costs of inaction which climatic destabilization would inevitably inflict.

It is for these reasons that we call upon our political and corporate leaders to face their responsibilities and take immediate action to protect our climate.

We urge members of the public and all non-governmental organizations to organize grass-roots movements to exert pressure on our governments to ensure they achieve this goal.

Too much time has already been wasted and it is running out fast. We cannot wait until major climate catastrophes strike the developed world and wake us from our slumber - by then it will be too late. We need political action now. A crash program is therefore an imperative. We have no alternative.

After reading the declaration, we were shocked to discover that it did not cite a single scientific paper that would validate any of its claims. Moreover, we are aware of many peer-reviewed scientific journal articles that describe experimental studies of real-world phenomena that directly refute the Declaration’s multiple claims of crisis. In what follows, we review these materials and show how they demonstrate the near total absence of scientific support for essentially all of the Ecologist’s contentions.

· Evidence of human impact upon the earth’s climate is now irrefutable.

This statement from the Ecologist suggests that the rising global temperature that accompanied the demise of the Little Ice Age, which doomed the Viking settlements on Greenland and held much of the planet in its frigid grip until the turn of the last century, is irrefutable evidence of man’s impact on climate. Actually, it is much more likely that the warming of the earth over the past century or so is merely a manifestation of the natural temperature variability that is regularly experienced by the earth on quasi-millennial time scales.

Approximately 700 to 1100 years ago, for example, during the Medieval Warm Period, earth’s temperature was almost as warm as it is today (Lamb, 1984; Grove, 1988; Lamb, 1988). What is more, atmospheric CO2 levels back then were about 20% less than they are now (Etheridge et al., 1998). Similarly, during the Climatic Optimum that prevailed from 7,000 to 9,000 years ago, air temperatures were as much as 2°C warmer than at present (Houghton et al., 1990), and the CO2 content of the air was approximately 30% lower than it is today (Boden et al., 1994). Hence, there is no compelling reason to believe that rising CO2 levels are causing the world’s temperature to rise. Something else – or nothing else, i.e., natural unforced climatic variability – has caused even greater warming and cooling in the past; and if it’s done it before, it can do it again. In fact, climate history is even better than human history in repeating itself.

· Climate will become more and more unstable, marked by extreme and unseasonal weather.

Several scientists have examined a host of temperature records in search of trends in temperature variability over long periods of time. Parker et al. (1992), for example, analyzed the variability of daily temperatures in central England since the mid-1700s, finding no clear evidence of trends toward higher variability in recent decades. In addition, Karl et al. (1995a) searched for evidence of changes in temperature variability in the USA, the former Soviet Union, China, and Australia. Instead of increasing temperature variability, however, they discovered trends of decreased temperature variability on 1- to 5-day time-scales. They also reported that the interannual variability of temperature showed no consistent pattern across the three Northern Hemispheric areas over their period of study, but that Australia experienced statistically significant decreases in interannual variability in September-November for maximum, minimum, and average temperatures, especially in its temperate regions. In fact, even the Intergovernmental Panel on Climate Change (IPCC) – which sometimes "strains at a gnat" to find signs of human involvement in climatic phenomena – has concluded that "temperature shows no consistent, global pattern of change in variability" (Houghton et al., 1996). It is clear, then, that when the actual data are scrutinized, there is no evidence to support the claim that climate is becoming increasingly more unstable and marked by heightened extremes and unusually unseasonal weather.

· Food supplies will be affected dramatically by increased droughts, heat waves, and pests.

This statement suggests that global warming will adversely affect food production via unsubstantiated CO2-induced climatic catastrophes. However, the peer-reviewed scientific literature actually reveals a positive picture of what would likely occur if both the atmosphere’s temperature and CO2 content continue to rise.

With respect to drought, nearly all of earth’s plant life responds to increases in the CO2 content of the air by increasing its productivity and biomass (Kimball, 1983a, b; Cure and Acock, 1986; Mortensen, 1987; Lawlor and Mitchell, 1991). Moreover, this positive growth enhancement typically occurs with less water-use per unit leaf area. Thus, the amount of atmospheric carbon incorporated into plant tissues per unit of water lost, or water-use efficiency, generally rises with increasing levels of atmospheric CO2 (Fernandez et al., 1998; Rey and Jarvis, 1998; Szente et al., 1998; Tjoelker et al., 1998; Tognetti et al., 1998; Wayne et al., 1998); and this phenomenon allows plants to better deal with drought and inadequate levels of soil moisture. Furthermore, under conditions of extreme or prolonged drought, atmospheric CO2 enrichment helps plants survive and attain a fuller recovery more rapidly upon re-watering (Kriedemann et al., 1976; Converse and George, 1987; Idso et al., 1989, 1995; Johnson et al., 1997; Arp et al., 1998; Ferris et al., 1998; Tuba et al., 1998).

With respect to heat waves, atmospheric CO2 enrichment is again a helpful antidote. In fact, higher CO2 concentrations actually allow most plants to grow even better at elevated temperatures than they do at lower temperatures. In a comprehensive analysis of 42 different experiments, for example, Idso and Idso (1994) found that the percentage growth enhancement resulting from a 300 ppm increase in the air’s CO2 content became progressively greater with increasing air temperature, going from close to zero at 10°C to 100% at 38°C.

This relative growth enhancement typically occurs because photorespiration, which is most pronounced at high temperatures (Hanson and Peterson, 1986) and which decreases the efficiency of photosynthesis, is effectively inhibited by elevated levels of atmospheric CO2 (Grodzinski et al., 1987). In fact, this positive effect of elevated CO2 is so strong, it can actually shift optimum plant growth temperature upward (Berry and Bjorkman, 1980; McMurtrie and Wang, 1993; Cowling and Sage, 1998). Consequently, if atmospheric CO2 and air temperature rise concomitantly in the future, they will likely work together to promote even greater plant growth and development, as new investigations continue to demonstrate (Vu et al., 1997; Hakala, 1998; Bunce et al., 1998; Reddy et al., 1998).

As far as pests are concerned, the little work that has been done in this area suggests that as the CO2 content of the air increases, plants will likely develop better defensive mechanisms than they had at lower CO2 concentrations. Many secondary metabolites, for example, accumulate in leaves to serve as deterrents against herbivory; and elevated levels of atmospheric CO2 often increase the amounts of these defensive compounds or the proportion of carbon allocated to them (Fajer et al., 1989; Lindroth et al., 1993; Gleadow et al., 1998), thus providing plants with a greater level of protection against herbivores.

· Rising sea levels will cause substantial damage to agricultural land, cities, and towns.

If sea levels dramatically rose for any reason, this statement would have some validity. However, as CO2 cannot be implicated as the cause of past global warming, it cannot be implicated as the causative agent of potential future sea level increases. In fact, not even global warming itself can ensure that sea levels will rise. Over the past 2000 years, for example, archaeological and geologic data suggest that average global sea level probably fluctuated no more than a few tens of centimeters (Hofstede, 1991; Tanner, 1992; Varekamp et al., 1992; Flemming, 1993), while average global temperature changes over this period were at least as large as the modest global warming of the last century (Houghton et al., 1990). Thus, it is highly unlikely that sea levels will rise another 75 to 90 cm over the next century to fulfill this apocalyptic prophecy.

· There has been a sharp rise in extreme weather events.

Has the frequency and/or intensity of various forms of severe weather increased in the recent past, and if so, can the blame be placed on CO2-induced global warming? In an interesting study that broached this question, van der Vink et al. (1998) determined that the costs of natural disasters in the United States have indeed increased significantly over the last decade. However, these higher costs could not be linked to a corresponding increase in the frequency or severity of natural events. Instead, the increased costs were associated with (1) more people moving to coastal areas that are vulnerable to natural hazards, (2) the effect of this population shift being amplified because the people moving to these areas come from the wealthier segment of society, and (3) the wealth of these already wealthy people has been rising at a dramatic rate. Thus, they concluded that our increasing vulnerability to natural disasters is a consequence of societal trends, and not weather or climate trends.

In an illuminating example of this phenomenon, Pielke and Landsea (1997) examined U.S. hurricane damage trends over the last 70 years, estimating the damage likely to occur if past hurricanes were to hit today. Incorporating relative inflation, wealth statistics, and population, they found that the most damaging hurricane (relatively speaking) occurred in Florida in 1926, causing almost twice the damage of Hurricane Andrew, indicating that severe weather events can occur at anytime, regardless of global temperature or greenhouse gas concentrations.

In terms of direct weather observations, there has been no demonstrable trend in the activity of western North Pacific hurricanes over the last 50 years (Bouchard, 1990; Black, 1992), nor has there been any trend in the number of hurricanes crossing the coast of the USA in the entire last century (Karl et al., 1995b). However, a number of researchers have reported a decrease in both the intensity and frequency of Atlantic hurricanes. Gray (1990), for example, examined Atlantic tropical cyclone activity over the period 1947 to 1987, finding that hurricane activity from 1970 to 1987 was less than half that observed between 1947 and 1969. In addition, Landsea et al. (1996) found that the mean maximum wind speed of North Atlantic hurricanes decreased since the mid-1940s and that there has also been no significant trend in the peak intensity reached by the strongest Atlantic hurricane each year for the five past decades.

With respect to extra-tropical storminess, Schmidt and von Storch (1993) used daily air pressure observations at three stations in the south-east North Sea to calculate the annual distributions of daily geostrophic wind speeds and concluded that the frequency of extreme storms in this area has not changed in the past hundred years. Likewise, von Storch et al. (1993) analyzed local wind observations and found little trend in the number of severe storm days over a long time period in Iceland. They also examined high water levels at Hoek van Holland and found that once the effects of tides and sea level changes were removed, the resultant time-series revealed no trend in the frequency of extreme surge heights. Similarly, Zhang et al. (1997) evaluated storm surge data at two Eastern US cities and noted no significant trend in the number and intensity of storms over the last century. And the IPCC itself states that, with respect to extra-tropical storminess, "there is no clear evidence of any uniform increase" (Houghton et al., 1996).

What about droughts? Are we experiencing more droughts of greater severity due to rising global temperatures? In the 1970s, the United Nations and other organizations heavily publicized the droughts in the Sahel of Africa and claimed that extreme and possibly irreversible desertification was occurring in the region as a result of both human and climatic influences. However, history proved them wrong; and subsequent studies of vegetative cover using satellite images to infer plant productivity have alleviated fears of massive desert expansion in the Sahel and demonstrated the resilience of the native vegetation (Nicholson et al., 1998; Prince et al., 1998).

In the United States, meanwhile, Woodhouse and Overpeck (1998) used various proxy data indicators to assess the frequency and severity of drought in the central part of the country over the last two thousand years. They determined that this region has experienced numerous "multidecadal- to century-scale droughts," leading them to conclude that "twentieth-century droughts are not representative of the full range of drought variability that has occurred over the last 2000 years." In addition, they noted that the most recent century has been characterized by droughts of "moderate severity and comparatively short duration, relative to the full range of past drought variability."

In leaving this subject, it is plain to see that a sharp rise in extreme weather events has not occurred over the past century or so.

· As warming increases, the carbon dioxide-absorbing function of the world’s forests will weaken and even cease to operate.

This statement flies in the face of the peer-reviewed scientific literature that has already been cited in earlier sections of this response. Briefly, if temperatures continue to rise, even by as much as that predicted by climate models, the concomitant rise in the CO2 content of the air will more than compensate for the warming. For a doubling of the air’s CO2 content, for example, the optimum growth temperature of several plants has been observed to rise by approximately 5°C (Idso and Idso, 1994). Thus, plants will not be forced to migrate polewards towards cooler climates to survive. In fact, plants will continue to persist, if not expand (Idso, 1995), in their current ranges, exhibiting productivity levels much higher than they exhibit at lower air temperatures and atmospheric CO2 concentrations (Idso and Idso, 1994). Therefore, the CO2-sequestering power of the world’s forests will likely increase if temperatures and CO2 concentrations continue to rise; and this phenomenon may become so great that earth’s vegetation may actually remove all of the carbon dioxide annually released into the atmosphere by mankind’s activities, as has recently been shown to be occurring on the North American continent (Fan et al., 1998).

· Rising temperatures will trigger a huge die-back of trees, causing billions of acres of South American rainforest to turn into desert.

Once again, the scientific literature indicates that this scenario is about as far from reality as one can possibly get. In fact, in a recent study of tree biomass changes at hundreds of mature tropical forest research sites located all around the globe, Phillips et al. (1998) found that, from 1958 to 1996, tropical forest biomass increased at such a rapid rate that forest growth in Central and South America alone could account for approximately 40% of the world's missing carbon sink.

· The unstated specter: will more CO2 doom biodiversity?

In light of its proclamations of rampaging weather and massive forest die-back, one might logically assume that the authors of the Ecologist’s declaration would not be optimistic about the future of earth’s biodiversity. But what are the facts?

In an experiment where one might have expected atmospheric CO2 enrichment to work against the preservation of biodiversity, Taylor and Potvin (1997) found no significant effect of elevated CO2 on species richness in managed prairies near Montreal, Quebec. In particular, elevated CO2 did not favor the growth and colonization of Chenopodium album (a common agricultural weed) at the expense of slower-growing native prairie species following human-induced ecosystem disturbance. A similar result was reported by Luscher et al. (1998), who exposed multiple genotypes of twelve fertile grassland species common to Switzerland to double the normal concentration of atmospheric CO2 for three years and observed that elevated CO2 did not act as a natural selective factor among them. In both of these situations, therefore, the data suggest that elevated CO2 would, at a minimum, act to maintain biological diversity, even in the face of significant ecosystem disturbance.

In another study, Arp et al. (1998) grew six perennial plants common to The Netherlands in treatment combinations of low and high soil nitrogen, low and high soil water, and ambient and elevated atmospheric CO2 for two full years. Their results indicated that "elevated CO2 tends to favor species already best adapted to their environments." Moreover, they stated that "a rise in CO2 would not change the relationships between plant species in the natural environment, but would reinforce existing ones."

So why does atmospheric CO2 enrichment help to maintain the species status quo in situations such as these? Some insights may be gained from Simard et al. (1997), who studied nutrient transfer among trees in a temperate forest and discovered that nutrients are passed along a complex network of fungal mycelium from trees that have an abundance of nutrients at their disposal to those that are lacking them, regardless of species. This finding suggests that competition among plants may not play as great a role in natural ecosystems as once believed, as this nutrient-sharing phenomenon would appear to promote species coexistence and maintain, or even enhance, ecosystem biodiversity.

Within this context, it is instructive to note that elevated levels of atmospheric CO2 enhance belowground growth and stimulate the root activities of most plants (Curtis et al., 1990, 1994; Idso and Kimball, 1992; Norby, 1994; Prior et al., 1995; King et al., 1996). One such CO2-enhanced process is the exudation of nutrients and carbon compounds (Rogers et al., 1992), which stimulate microbial and fungal activities in the vicinity of plant roots (Lamborg et al., 1983; Pregitzer et al., 1995; Tingey et al., 1996; Lazarovits and Nowak, 1997; Ringelberg et al., 1997). Consequently, as the air's CO2 content continues to rise, these phenomena should lead to the development of ever better mycelial networks for distributing nutrients among plants, enhancing their transfer from the "haves" to the "have-nots."

Most recently, van der Heijden et al. (1998a,b) determined that ecosystem plant biodiversity is directly dependent upon the presence of a diverse assemblage of soil fungi. Specifically, they found that plant biodiversity typically rises with an increase in the number of species of arbuscular mycorrhizal fungi living in an ecosystem's soil. And with more CO2 in the air, enabling plants to pump more carbohydrates into the belowground environment, there is a greater resource base for supporting a greater diversity of such fungi in the soil, which helps to maintain, and even promote, the diversity of aboveground plants within the ecosystem. Furthermore, simple logic would suggest that the potential for expanding the diversity of an ecosystem's animal populations would thereby be enhanced as well, as different herbivores often prefer different types of vegetation.

IN CONCLUSION, it is abundantly clear that the apocalyptic statements of the Ecologist’s "Declaration on Climate Change" are not supported by studies of real-world phenomena as reported in the peer-reviewed scientific literature. Hence, they do not even provide a weak platform for the journal’s policy recommendations. In fact, it is likely that their proposals would actually jeopardize the ability of earth’s vegetation to deal successfully with various environmental stresses that may arise in the future, reducing our ability to produce the increased quantities of agricultural and timber products needed to feed, clothe, and shelter the growing population of the planet. It is therefore prudent that all documents and declarations recommending extreme policy measures, such as this one, be closely examined, lest in an uninformed "rush to judgement" we inadvertently bite the hand that feeds us.

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About the Center

The Center for the Study of Carbon Dioxide and Global Change was created to disseminate factual reports and sound commentary on new developments in the world-wide scientific quest to determine the climatic and biological consequences of the ongoing rise in the air’s CO2 content. This it does through mini-reviews of recently published peer-reviewed scientific journal articles, books, and other educational materials published twice a month on the Internet. In addition, to help both students and teachers gain greater insight into the biological aspects of potential global change, the Center conducts real-time on-line experiments in its "Global Change Laboratory," where the expanding databases of its ongoing biological studies are updated weekly, and where instructions in the "Poor Man’s Biosphere" approach to atmospheric CO2 enrichment and depletion experiments enables all interested parties to conduct similar studies in their own homes and classrooms. Visit our web site regularly, now operating on the Internet at http://www.co2science.org and become a part of our research team. Your results can be shared and compared with those of other investigators around the globe.