SENAT
Report n° 230 (2006-2007) by M. Christian GAUDIN, Senator (for the parliament office for the evaluation of scientific and technological choices)
Disponible au format Acrobat (12 Moctets)
III. THEMATIC DEBATE - THE POLES: INDICATORS AND EVIDENCE FOR MANKIND
A. MS. NELLY OLIN, MINISTER OF ECOLOGY AND SUSTAINABLE DEVELOPMENT
President of the Senate,
Your Serene Highness,
President of the Parliamentary Office for the Evaluation of Scientific and Technological Choices, my dear friend,
Senator Gaudin, my dear friend Christian,
Honourable Members of Parliament,
Honourable scientists,
Ladies and gentlemen,
The poles are special places which play a key role in the global system of our planet.
They act as catalysts for international cooperation.
Alone, it is impossible to comprehend these regions geophysical phenomena, and no one can appropriate them.
Since 1882, each International Polar Year has thus been an opportunity to reaffirm the necessity for a multi-thematic mobilization to make progress in our understanding of the phenomena at stake.
The momentary concentration of our research and communication efforts should result in our making faster progress with regard to our overall understanding of our planet.
In the past, during the Great Depression of 1932-1933, this scientific mobilization allowed for a justification of the important grants made to research.
This was during the second IPY, which studied the planet-wide implications of the newly-discovered Jet Stream.
More important still, this same scientific cooperation leant support to arguments in favour of a freeze of territorial claims in Antarctica, eventually validated by the Antarctic Treaty signed in 1959 at the close of the third International Polar Year.
Antarctica, set aside as a world heritage site, nevertheless remains the target of largely-economic attempts at appropriation, for which France remains ever vigilant.
This fourth International Polar Year will undoubtedly prove itself useful for the same reasons.
The issues which today justify international scientific cooperation have nevertheless changed.
As Professor Le Maho I'm sure agrees, it is no longer a question of seeking to understand the stable dynamics of a system in which we include our actions, but rather to better understand the dynamics partially resulting from our own actions.
The poles are privileged locations for the carrying out of this research, for they act as indicators of our actions and of the consequences of these actions.
Once distant, exotic lands, the frontiers of the known world and the objects of expeditions in which national pride went hand-in-hand with the scientific approach, the poles today serve as our most valuable indicators and evidence - at once close, because directly linked to the consequences of our actions, and reliable, because they scrupulously retain the traces of these same actions.
The poles testify to our past. They retain records of the variations in climate and in the chemical composition of the world's atmosphere.
In an ice core, it is possible to read certain events in the history of mankind: nuclear tests, the international Montreal Treaty (from which date the atmospheric concentration of CFCs has declined), the introduction of unleaded fuels, etc. One day, I hope to be able to read the effects of the Kyoto Protocol.
These archives cannot be falsified - that is, as long as they exist.
The poles also serve as privileged testimony for the present.
They have ringside seats to climate change, exposed as they are to tangible climatic developments.
Thus, the poles send back to us an honest picture of the present consequences of human activities.
As will be discussed by Valérie Masson-Delmotte, Yvon Le Maho and Joëlle Robert-Lamblin, climate change affects the equilibrium of these regions as much as it affects their unique biodiversity and the peoples who inhabit them.
Today, the polar regions are the site of significant changes, whose developments are amplified and accelerated at the poles.
Average Arctic temperatures have risen almost twice as fast as the world average over the past one hundred years. In general, the temperatures at the top of the Arctic permafrost have increased since 1980 (up to 3°C).
The frozen regions' maximum seasonal surface area has decreased by around 7% since 1900 in the northern hemisphere, with a spring decrease of up to 15%.
The paleoclimatic data confirms the hypothesis that the global warming of the past half-century is atypical, for at least the past 1,300 years.
The last time that the polar regions were significantly warmer than they are today for a long period of time (around 125,000 years ago), the reduced volume of polar ice led to a rise in sea levels of between four and six metres.
For the next one hundred years and for all the scenarios studied by the IPCC, the simulations predict a decrease in sea ice in both the Arctic and the Antarctic.
According to certain simulations, the ice will almost completely disappear in the Arctic at the end of summer in the second half of the 21st century.
The impact of climate change on the polar regions is both uncertain and potentially considerable.
Could the Greenlandic icecap collapse? If so, what would the consequences of this collapse be?
Will the northern sea route between Europe and Asia open up? If so, what would be the economic, ecological and geopolitical consequences of this new passage?
Faced with these changes that can be observed at the global level and for the study of which we support the international scientific mobilization effort, the local behaviour of the Arctic peoples is especially informative.
These societies, which are intimately connected with their environment, do not benefit from the same distance and global vision as we do. As a result, climate change, felt locally, is not always perceived as a threat in the case of certain Siberian groups. On the other hand, it is very much a reality for a number of settlements in Alaska. These groups have had to adapt. However, the ability of these once nomadic and now sedentary peoples to adapt is reaching its limit.
Because we benefit from the necessary distance and are aware of the future impacts of climate change, we are accountable - before both these peoples and future generations - for our efforts to understand, anticipate and control the consequences of human activities on the ecosystems.
For this reason, it is a good idea to underline the direct impact of human activities on the biodiversity specific to the polar regions.
The image of the drowning polar bear - exhausted after swimming tens of kilometers and incapable of getting back to the ice shelf, after having been carried too far off by a small ice floe in its effort to catch fish - certainly attracts media attention, but oh how unbearable it is to watch!
I would here like to emphasize the seriousness and importance of biological research. While it is true that media exposure of the biodiversity crisis has generated public awareness of the threats to biological diversity, this media coverage - let's be honest - is not equal to the gravity of the situation.
It is only through biological research that we will be able to consider the adaptability of ecosystems, anticipate biological invasions, prevent the potential impacts of a growing tourist industry, and assist bio-exploration.
I would here like to congratulate French biological research in the sub-Antarctic regions. This research, I am proud to point out, is ranked number one in the world (according to a study conducted by the Paul-Emile Victor Institute) and has developed numerous innovations which are now widespread.
Faced with all of these scientific and human challenges, the Ministry of Ecology and Sustainable Development intends to play its part in the international mobilization effort for the IPY and, more generally, through its policy on polar research and the management of the polar territories.
With regard to polar issues, the French community and the Ministry of Ecology are making a great effort.
Evidence of this mobilization can be seen in the unprecedented effort of the French scientific community to develop climate scenarios. These scenarios are presented in the fourth evaluation report of the IPCC.
The work thus carried out by the French computation centres (IDRIS, CEA, the Météo-France centre) has allowed for all the components of the climatic models to be improved and their precision to be increased. This project represents more than 20,000 computation hours for the Pierre-Simon Institute and Météo-France.
This institute is currently setting up a scientific interest group on the impacts of climate change, which I proudly support.
To complete our understanding of climate by drawing lessons from the past, French researchers are concentrating heavily on - and are famous in - the field of paleoclimatology. This was once again shown by the work carried out on the glacial records frozen within the polar icecaps and which allowed scientists to confirm the link between climate change and greenhouse gases.
French involvement in such international programmes as the Antarctic ice coring provides us with new pieces to complete the very complex puzzle of global climate.
I would also like to emphasize France's strong commitment to the preservation of biodiversity, as evidenced by the creation last October of the nature reserve of austral territories.
This reserve, it should be pointed out, covers 700,000 terrestrial hectares and 1.6 million sea hectares, between the sub-Antarctic zone and the subtropical zone, including the Crozet, Kerguelen, Saint-Paul and Amsterdam islands. Very isolated, located at more than 2,000 kilometres from the nearest continent, this reserve represents a unique sanctuary which must be preserved indefinitely.
This reserve is also an exceptional site for carrying out quality research on the living environments of the sub-Antarctic regions.
I intend that this nature reserve be managed in synergy with the research projects.
Regarding specifically the International Polar Year, the programme of scientific research and interdisciplinary observations, launched in a coordinated manner, has two objectives.
Firstly, it seeks to improve our understanding of the polar processes, as well as their links, by considering both the Arctic and the Antarctic and by coordinating heavy logistical means, such as ships and satellites.
Secondly, it seeks to inform and raise the awareness of the general public, the media and decision-makers regarding the importance for society of work carried out in these extreme zones.
Among the 209 projects recognized at the international level, 55 have a French component and five are directed by a French scientist. The Ministry of Ecology is extremely attentive to work carried out within the framework of the IPY, considering the importance of the environment for these zones.
Concerning this matter, I would like to point out my ministry's role in maintaining a strong French position on protecting Antarctica from any unreasonable economic development; in particular, this means forbidding the installation of any long-term infrastructure for tourism, as well as strengthening legislation and the power of the police.
Finally, I would like to conclude with the Tara Arctic expedition - a fine example of scientific collaboration meant to raise awareness among the general public.
This drifting expedition in the Arctic, led by Etienne Bourgois, is a scientific and human adventure, whose aim is to raise awareness among the world's population of the importance of ecological balances.
This scientific expedition lies within the framework of the International Polar Year through the European DAMOCLES programme, whose aim is to observe, understand and quantify climate changes in the Arctic.
My ministry is, of course, associated with this expedition, by helping to bring into play practices for reducing energy consumption and by supporting the expedition's efforts to raise awareness among the general public.
There you have it, ladies and gentlemen - that's all I wanted to say. I thank you for your kind attention.
Bruno ROUGIER
Thank you, Minister Olin. Following the exposition of the scientific importance of this International Polar Year and before moving on to the next three talks, I would like to address Senator Gaudin. Mr. Gaudin, in your report, you emphasized that the research programmes must last several years.
Christian GAUDIN
Indeed, all research implies the accumulation of a given potential. For example, in the field of animal biology, the study of certain species over the past fifty years has allowed us to create a database that is the envy of the world. We are able to trace the adaptations of these species to both changes in climate and their life in an extreme environment.
Today, it is important to provide the necessary means for the continuation of this research, in areas that are very difficult to access and where the scientists' living conditions are rather uncomfortable. To provide the necessary logistics, we need to pursue a mutualization via a coming together of the EU member countries. France cannot act alone; it needs this European group in order to act on the world stage at a time when numerous countries - in particular, the emerging nations - are well aware of the strategic importance of this research.
Bruno ROUGIER
Thank you, Senator Gaudin. We will now learn about a few of the studies currently under way, via three themes: the ice and the information contained therein, biodiversity, and the Arctic peoples.
We will start with the Antarctic ice, a veritable climatic archive. A sampling carried out in Greenland has allowed for climate reconstructions going back as far as 123,000 years - in Antarctica, scientists have gone as far back as 800,000 years.
Valérie Masson-Delmotte, who will present this subject to us, is a paleoclimatologist and heads the Glacios team at the Laboratoire des Sciences du Climat et de l'Environnement (Laboratory of Climate and Environmental Sciences), a mixed CEA-CNRS research team connected to the University of Versailles-Saint-Quentin and the Pierre-Simon Laplace Institute (IPSL). Via this enumeration, I would like to salute all the organizations working in this sector.
In 1997, you carried out ice corings over a period of two months. Since then, you have participated in numerous projects, both in France and abroad. Therefore, I would like to ask you to tell us our history, via the ice.
B. MS. VALÉRIE MASSON-DELMOTTE, CLIMATOLOGIST, CEA
The poles: indicators and actors of climate change
Thank you. Unfamiliar with all the subtleties of protocol, I will simply say "Hello, ladies and gentlemen" and I would particularly like to address those of you interested in the poles.
The image of the Concordia station illustrates the impression one has in the polar regions of being far from the tumultuous world. There, one can find the slow components of the climatic machine: in the polar seas are formed the deep waters which carpet the depths of the oceans, while the polar ice records, year after year, the history of the climate. Those persons who have visited Concordia have therefore walked on ice that is 800,000 years old.
Far from the tumultuous world, certain polar regions are nevertheless subjected to extremely rapid changes. Thus, in the Arctic, the ice shelf has shrunk by two million square kilometers. Since 1975, the observation of the poles by satellite has allowed for an improved observation of the changes at the poles. We have thus discovered a significant decrease in the extension of the sea ice, as much in winter, with a shrinkage of 4.5% per decade, as in summer, particularly over the past few years.
To this shrinkage must be added significant variability from one decade to the next. Our ability to distance ourselves from these variations, via the data obtained by satellite, remains slight. That is why we also make use of climatic models, which allow us to predict the impact of human activity on the ice cover. Thus, the Météo-France model predicts that the Arctic ice shelf will disappear by 2060, while the IPSL model predicts the same result for the year 2080. If the next International Polar Year is held in fifty years, the ice cover over the Arctic will therefore have almost completely disappeared. This amounts to a global warming of 3.5°C, corresponding to a continuation in the release of greenhouse gases at the present rate - in other words, based on an increase of 25% since 1990.
In Antarctica, we have observed a shrinkage of the minimal sea-ice extension of around 25%, with important consequences for the ecosystems which have adapted to this cover.
Changes in temperature have been measured since the International Geophysical Year of 1957-1958, which saw the installation of numerous weather stations in these zones. Temperature records from before this time are very rare. We have therefore been able to measure a general increase of 0.6°C since 1958, which has had very different effects on the various polar regions: the Antarctic Peninsula and certain Arctic regions have undergone a warming of more than 2°C, while in other regions, the great ten-year variability, as well as the atmospheric and oceanic circulation which redistributes the planet's heat, have reduced this warming trend.
No matter what we do, the average temperature will continue to increase: global warming will amount to 2°C if we do everything in our power to curb this trend, but it will surpass 3.5°C if greenhouse-gas emissions continue at their present rate.
Therefore, the scientific community is certain of some things: in particular, it expects a further increase in greenhouse-gas emissions, which will accelerate climate warming in the Arctic. However, considerable uncertainties remain: a global warming of 3.5°C represents an uncertainty of almost 3°C at the world level, with a factor of two in the Arctic. It is urgent to reduce this uncertainty and the dispersion between the climatic models. The answer is to systematically test them by the yardstick of their capacity to represent the great climatic changes of the past.
The following elements are responsible for the climatic specificities of the polar regions:
- magnifying mechanisms;
- the melting ice shelf;
- the link between the atmospheric and oceanic circulation and the extension of the sea ice;
- the link between the carbon cycle, with carbon contained in the permafrost, and the Antarctic Ocean plays a critical role in the overall assessment of carbon dioxide;
- the possibility of ruptures, in these regions with a slow time-constant, as can be seen in the extension of the sea ice in the summer;
- the lack of meteorological records over the long term, despite our increased level of knowledge.
To go further, intensive observation programmes must be combined in order to map out the changes currently under way in the polar regions, and these meteorological series must be interpreted using the history of the climate as recorded in the ice.
The two ice samples presented here were made during the EPICA ice-coring project at Dome C in Antartica. This is the result of both an international partnership gathering together ten countries and logistical, technological and scientific know-how.
The oldest ice cores - 123,000 years for the North GRIP site in Greenland and 800,000 years for the Dome C site in Antarctica - lie within the framework of a project to develop a 10-year research strategy, whose objective would be to go further back into the past and to map out, in both time and space and using different time scales, the evolution of the climate in the polar regions.
This graph, therefore, retraces 800,000 years of temperature change in the Antarctic. The natural rhythm shows a succession of ice ages and warm periods, with a transition period in the region of 10,000 years. The amplitude of a glaciation is 10 degrees in the Antarctic and 25 degrees in Greenland, with a global average of 4 to 7 degrees. In the past, due to the Earth's position in its orbit around the sun, the poles have known warmer periods than the present.
During the last interglacial period, which more or less corresponds to the appearance of our species, the temperatures at the two poles were some 5°C warmer than they are today. This is the maximum climate warming recorded on these time scales. Sea levels were four to six metres higher than they are today. For natural reasons, a persistent warming at the poles can have an effect on the overall mass of the polar ice caps and, consequently, on the sea level, as well.
A direct link can also be seen between the changing temperatures in Antarctica and the concentrations of carbon dioxide. In the past, natural variations of this concentration, a major amplifier of these glaciations, were responsible for half of the amplitude between the glaciations and the warm periods. Thus, one can measure the extent of the human disturbance, over the past 150 years, since the beginning of the industrial period, which represents the radiative equivalent of past natural changes between the warm and interglacial periods.
The climate's natural rhythm has therefore been broken: in the past, the Earth's orbit governed glaciations, which were amplified by the concentrations of greenhouse gases. Today, it's greenhouse gases that are driving the climatic system. Therefore, we no longer have any analogy for understanding the effects of these emissions on the climate. However, we can use periods of climate warming observed in the past to test the ability of our climate models to represent these great changes.
I mentioned earlier the sea levels. In its 2007 report, the IPCC presents the current state of our knowledge on this subject. Between 1993 and 2003, observations made by satellite revealed an increase in sea level of some 3 mm per year, an important contribution made by the melting of the smaller glaciers and the thermal expansion of the ocean, as well as a significant role played by Greenland and Antarctica. However, for the latter case, the uncertainties remain great, because it is difficult to assess the ice cap's mass. Most satellite-based observations of the altitude of this ice cap go back less than ten years, with the gravimetric observations going back only three years. In these conditions, it is difficult to correct for annual or ten-year variations.
Long-term estimations can result from a combining of, on the one hand, on-the-ground expeditions planned for the IPY, superficial sampling and measuring past variations in the accumulation and outflow of ice, and, on the other hand, satellite-based measurements offering a larger-scale coverage.
To give you some rough estimates, we have observed a 20-centimetre rise in sea level over the 20th century, while the estimated risk for the 21st century is between 19 and 58 cm. One must take into account the great uncertainties regarding the polar icecaps, the accumulation of snow and the effects of outflow.
Finally, the poles are both indicators and actors of climate change. There are two parts to the scientific community's strategy:
- understand the past climatic variability and the reaction of the polar icecaps via ice coring;
- map the climate change currently under way at the poles and its processes at the level of the atmosphere and oceanic circulation, the melting of the Arctic ice shelf and the reaction of the polar icecaps, by bringing together on-the-ground programmes and remote-sensing programmes.
Both parts of this strategy are essential in order to improve the climate and polar-icecap models, the only tools we have to predict and adapt to the future of the poles. A double linking is therefore necessary: first of all, between the various facets of climate research, and secondly, between these long-term studies and major societal issues.
In my opinion, the International Polar Year presents us with the opportunity to establish a pact between science and society, to show the young generations that it is possible to carry out science conscientiously, to understand the world and make oneself useful. Perhaps such a pact will give rise to new vocations. Thank you.
Bruno ROUGIER
Thank you, Valérie Masson-Delmotte. We will now turn our attention to the animals that live on the ice shelf. We know that the polar regions' biodiversity is threatened by climate change. One of the ice shelf's emblematic animals, the emperor penguin, has two surprising characteristics. First of all, the male emperor penguin can go without food for up to four months in order to look after its egg, while the female penguin searches for food. Secondly, a biological process sends the male a signal when the time has come for it to once again feed, abandoning if need be its egg. Even more surprising is the fact that this signal takes into account the amount of time necessary to search for food.
I know, Mr. Le Maho, that you will not limit your talk to the emperor penguin. Nevertheless, it is one of your favourite subjects. I should point out that you are a biologist at the CNRS, the assistant director of the Hubert Curien Interdisciplinary Institute, a member of the Council on Scientific and Technological Programmes at the Polar Institute, and a member of the French Academy of Sciences.
C. MR. YVON LE MAHO, BIOLOGIST, CNRS
Biodiversity at the poles: a treasure under threat
Your Serene Highness,
Honourable Minister,
President of the CNRS,
Secretary-General,
Honourable Members of Parliament,
Dear colleagues,
Dear friends of the poles,
Faced with these two major issues for the future generations, which are climate change and the preservation of biodiversity, there is no choice but to except that they are dealt with differently by the media. Climate change is beginning to be taken seriously, but, as Jean-Louis Etienne once said to me with his usual subtlety, one has the impression that, in the discourse on climate issues, the various forms of life are at best part of the scenery. Society has yet to fully grasp - excepting, perhaps, with regard to the polar bear - the seriousness of the extinctions caused by man. Set against our socioeconomic concerns, the preservation of biodiversity often seems like little more than a subject of interest.
Ever since the winter I spent in Adélie Land, how many times have I been told with a smile: "But of what use is the study of penguins? Are there not more serious research subjects, such as the genome?" Is climate, then, a serious research area for scientists, and ecology a subject for explorers, film-makers and photographers?
Far be it from me to minimize the role of Jean-Louis Etienne, Yann Arthus-Bertrand, Jean-Jacques Annaud, Jacques Perrin or Nicolas Hulot. Without them - in particular, Nicolas Hulot - there would have been no such spectacular realization of the importance of environmental issues during the presidential campaign. However, my objective here today is to show you that ecology is a perfectly genuine scientific domain. In particular, I would like to show you how the work carried out by the teams from the CNRS and the National Museum of Natural History - within the framework of the Paul-Emile Victor Polar Institute and in collaboration with teams from Great Britain, the United States, Japan, Australia and elsewhere - is at the forefront of research on the impact of climate change on biodiversity, which together, as we have seen, are the two principal themes of the International Polar Year.
For both the film-maker and the scientist, the actor remains the same: the emperor penguin. However, while the film-maker seeks to cause tears to fall and tongues to wag all over the planet, the aim of the scientist is to understand by which mechanisms the animal copes with its environmental constraints.
The March of the Penguins marvelously popularized the image of these males that, to look after their eggs, go without eating in the heart of the Antarctic winter in a cold that is extreme for man. After viewing the film, we come away with the idea that these males spend days, even weeks, tightly huddled together in order to survive four months without food. A moving image in the film is of these packs of emperor penguins breaking up, with the males overexcited by the return of the females to take over looking after the eggs. Naturally, as you may well expect, they're late!
On our side, we demonstrated some ten years ago that emperor penguins, by huddling together, are capable of lowering their energy expenditure, thereby reducing their metabolism by 25%. How is this done? Is it a sort of hibernation, in which the metabolism decreases with the internal temperature?
Thanks to progress made in microelectronics and microcomputing - which demonstrate the future interdisciplinary nature of ecology - miniature data-gathering systems of this type, known as "loggers", have allowed us answer this question. Indeed, we equipped emperor penguins with loggers that included temperature and light sensors. The light sensors are sensitive enough to allow us to obtain a signal even during the polar night; its disappearance means that the bird is in a very tight pack. In this manner, we were able to observe that the packs are continuously breaking apart and reforming, lasting on average only an hour and a half. Observing changes in the ambient temperature allows us to understand why: the temperature rises very quickly, to above 35°C.
Thus, we were able to observe how the mechanism by which the huddling emperor penguins save their energy reserves differs from hibernation. Their internal temperature is maintained at 37°C, allowing them to incubate their eggs at 36°C, and their reduced energy expenditure is linked to the decreased body surface exposed to the cold while closely huddling together. But the penguins are well-insulated and it quickly becomes very hot within the huddle: they paradoxically create a tropical environment and it is precisely for this reason that the packs quickly break apart and reform. In fact, it has nothing to do with the late arrival of the females. We are currently studying how the hatchlings, thanks to a similar mechanism, manage to reduce their energy expenditure and thereby accelerate their growth. Far from the cold being the principal problem, work carried out by our Chizé colleagues suggests that the halving of Adélie Land's penguin colony in the early 1970s is linked to a reduction in the surface area of the ice shelf due to warming.
Let us now consider the emperor penguin's closest relation: the king penguin. Here we are in Crozet, in what we call the French Galapagos, due to the many seabird colonies that find shelter there. The fact that the reproducing penguins do not huddle together, rather maintaining a territorial distance due to the some 1,500 pecks and pinion blows per day, is to be explained by the milder temperatures of the sub-Antarctic zone.
The temperature rarely falls below freezing in the 40°s and 50°s south latitude. Nevertheless, we will see that climate variations still have a significant impact. However, we must stop thinking - and I agree with Valérie Masson-Delmotte on this point - that the effect of climate is limited to temperature. Indeed, it is above all through its impact on marine resources that its influence is critical.
Thanks to loggers fitted with sensors, we can discover at what depth the birds feed (about one to two hundred metres down), as well as their speed, acceleration and hunting techniques. Thanks to other sensors monitoring how far they open their beaks, we can also monitor when they feed. The French teams, along with those from the British Antarctic Survey, were pioneers in this domain, as they were by equipping the birds with miniature Argos tags in order to track their movements about the oceans.
What have we learned? We discovered that the king penguins from Crozet, during their reproduction period, go to feed in the so-called "polar front" zone, while their partners remain with their eggs at the colony. Their trip is short - in other words, some 300-400 km - when the sea level is low, but longer - up to more than 600 km - when the sea level is high. However, sea level corresponds to the ocean's degree of dilatation, and therefore to its temperature. During warm years, the sea level is high, and, naturally, the level is low during cold years. Work carried out by our colleague at the Natural History Museum, Young-Hyang Park, has shown that these warm years, which result in longer sea trips for the penguins, are essentially linked to the El Niño phenomenon, which, after a certain time-lag, is transmitted from the Pacific to the Antarctic Ocean.
What are the consequences for the birds in the middle of reproduction?
Let us consider the male, that normally ensures the final three weeks of incubation, and the female, that after a fishing trip at sea, usually returns at the time of hatching to feed the chick. During a cold year, the female's short trip at sea allows it to return before the egg hatches. However, she comes back too late during a warm year. Yet, we discovered that the chick survives, because it is fed by the male, even though he has remained in the colony for two or three weeks.
Indeed, we have shown that, depending upon when he arrived, the male is capable of retaining between 400 g and 1 kg of food in his stomach. He is able to keep this food intact, without modifying the reproduction cycle, even though the temperature in his stomach is 37°C.
We were therefore interested in the penguin's food-preservation mechanism. Thanks to support from the Ars Cuttoli Committee, then presided over by Hubert Curien at the Fondation de France, following three years of research in analytical chemistry and molecular biology, we were able to identify a small protein associated with the preservation of fish in the king penguin's stomach. After having synthesized this protein, we demonstrated in vitro its great effectiveness against pathogenic bacteria and fungi, in particular those associated with nosocomial diseases. We are considering a biomedical development of this molecule.
Let us return to the case of the emperor penguin, which ensures the survival of its chick by regurgitating the food it has kept in its stomach. However, it doesn't wait indefinitely to do this. We discovered that an internal signal provokes the abandonment of the chick by the adult penguin so that it can go feed, after a twelve-day walk - in the same manner as a blinking light on the dashboard warns us when it is time to fill up. After having demonstrated that we can generalize the existence of this mechanism in the animal world, we discovered that it is linked to the secretion in the brain of a certain molecule, neuropeptide-Y, which makes the animal increasingly hungry. As you know, after a long period of not eating, it is dangerous to start eating again too quickly, because the intestine has become atrophied. Quite remarkably, because there has not yet been any ingestion of food, we have observed a cellular proliferation at the base of the intestinal villi and, what is even more extraordinary, an interruption of the apoptotic process - in other words, the dying-off of cells - at the extremity of the intestinal villi, thereby producing sorts of growths. Ordinarily, apoptosis appears during cancer. Consequently, these two mechanisms allow for an early, accelerated restoration of the intestinal villi.
Obviously, we were then interested in knowing if the penguins are completely protected from the effects of the polar climate by such survival mechanisms. To answer this question, we developed a new type of observatory, in which thousands of penguins have been automatically identified since 1998 thanks to microchips weighing less than 1 g planted under the skin. They are identified via the electromagnetic field created by antennas buried at the natural point of passage between the colony and the sea. Within the framework of the International Polar Year, we are coordinating an international project to develop these biology-based observatories.
What have we already learned? Despite their remarkable adaptations to climatic variations and the consequences of these variations on the marine resources, an increase of only 0.3°C in the sea's temperature results in a decrease of around 10% in the average annual survival rate for the emperor penguins.
Naturally, during the IPY, we must try to learn more about the emperor penguin's population dynamics, in particular the survival rate of the young. Nevertheless, a priori , this decreased survival rate for the adults is enough to engender a decrease in their populations and even their complete disappearance, should the rise in temperatures persist.
You would be right to point out that the environment is not limited to penguins. Therefore, I would like to speak to you about the work carried out by our colleagues in Rennes and Paimpont, which is interested in the consequences for the micro-fauna of climate warming and the lack of precipitation that has been observed since the mid-1970s in the eastern Kerguelen Islands.
As a result, there are now a sufficient number of days during which the temperature rises above 5°C to allow for the life cycle of the blue-bottle fly, or Calliphora . This fly, probably brought to the islands by boat from Réunion, has therefore succeeded in establishing itself in the archipelago and is now competing with the populations of the endemic, wingless fly, Anatalanta .
However, it would be overly-simplistic to limit man's impact to the indirect effects of climate change. In the austral islands, man has also introduced animals - cats, rabbits, rats, mouflon and mice - which today we are able to get rid of only on the small islands. Work carried out by research teams from the National Museum of Natural History and the CNRS at the University of Rennes demonstrates the impact of rabbits on an island in the Kerguelen Archipelago: Ile Verte (Green Island). Of the original vegetation - in particular, the Kerguelen cabbage and Azorella - essentially only one species remains, Acaena, and the island's soil has been badly eroded.
What happens when the rabbit is eliminated from the island? Restoration ecology is just as important as the study of the genome, or other scientific disciplines. Due, most likely, to climate warming, it is not the original endemic plants that are getting the upper hand of Acaena, but rather dandelions, an invasive plant introduced by man and which has colonized the entire island. All these phenomena add up, to the extent that today we are witnessing the disappearance of the original biodiversity and a homogenization of the environment.
I think you have understood that, looking beyond just images, the preservation of the polar regions' biodiversity is of major scientific importance and the International Polar Year represents an exceptional opportunity to meet this challenge. In collaboration with numerous international research teams, the French teams are at the forefront of an approach that is, I'm sure you have also understood, interdisciplinary in nature. It's a misconception that researchers are only interested in studying molecules. We are deeply moved by the beauty of the polar landscapes and the surprising spectacle of polar life in the high latitudes. I thank you for your attention.
Bruno ROUGIER
Thank you. After having touched upon the themes of ice and biodiversity, we will now consider the Arctic peoples. Some 3,750,000 persons, for the most part immigrants, live in these regions. The native populations have remained in the majority only in Greenland and in Nunavut, an autonomous Inuit territory created in 1999 in the Far North of Canada.
This talk will be presented by Joëlle Robert-Lamblin, ethnologist, anthropologist and member of the Laboratoire Dynamique de l'Evolution Humaine (Dynamic Laboratory on Human Evolution) of the CNRS. She has carried out research on the native peoples of the Arctic since 1966, studying in particular man's adaptation mechanisms to Arctic environments.
D. MS. JOËLLE ROBERT-LAMBLIN, ANTHROPOLOGIST, CNRS
The Arctic peoples: the "First Nations" and the first persons confronted with climate warming.
First of all, I would like to emphasize the fact that for the first time ever, an International Polar Year includes the human aspects (socioeconomic, cultural and political questions) in its research programme. It is precisely this human and social aspect of climate change in the Arctic that I will here discuss, in a somewhat simplified form, during my short talk.
Who are the Arctic's "First Nations"?
With regard to their origins, languages, lifestyles, cultural choices and political situations, the native peoples of the Arctic are characterized by a great diversity. However, they all live in close symbiosis with an extremely-harsh environment (intense cold, winter darkness, absence of arable land, etc.), making the most out of its resources.
These populations live spread out over vast territories encircling the Arctic Ocean. The areas in which they carried out their traditional activities have been considerably reduced by the influx of nonnative populations, which arrived during the 20th century to participate in the militarization or industrial exploitation of these regions.
Today, the demographic weight of the native Arctic peoples is weak. Now minorities in their own ancestral lands, they number less than 500,000 individuals, while the immigrants in their regions are nearly eight times as numerous. However, two territories are exceptions: Greenland and Nunavut, which became autonomous in 1979 and 1999, respectively, and whose populations are over 85% Inuit.
It will here be useful to provide you with a few demographic precisions regarding these populations placed under the sovereignty of seven countries.
Numbering some 140,000 individuals, the Inuit and the Yupik are divided between four countries: Denmark (for Greenland), Canada, the United States (for Alaska) and Russia.
The Aleuts, who belong to the same linguistic family, number around 12,500 individuals. For the most part, they are to be found in Alaska, but a few live in Siberia.
The Amerindians of Alaska and northern Canada - who belong, for the most part, to the Athapaskan group - number less than 26,000. To these can be added around 11,400 Tlingit and only 50 Eyaks.
In northern Europe, the Sami, or Laplanders, represent a community of some 70,000 persons divided between four countries: Sweden, Finland, Norway and Russia.
Finally, the "small" peoples of northern Russia, some twenty ethnicities, number barely 187,000 individuals. The largest community is that of the Nenets, with more than 41,000 members, but the smallest groups number only a few hundred individuals. Their ethnonyms are: Nenets, Enets, Khanty, Mansi, Dolgnas, Nganasans, Evenki, Eveny, Yukaghir, Chukchi and Koryaks, to name but a few.
It should be pointed out that the Sakha or Yakuts, who represent an important Turkic people numbering some 430,000 individuals, are not considered a native minority of Arctic Russia, even though they occupy a portion of this region.
Traditionally leading nomadic or semi-nomadic lives, all of these peoples have adapted to our planet's most extreme conditions, drawing all of their subsistence from an ecosystem which they do not consider inhospitable.
Some have adapted to the marine environment, such as the Eskimos (Inuit and Yupik), who have perfected their methods for hunting marine mammals.
Others, living in the tundra or taiga, have specialized in first hunting and then raising reindeer (this is the case of the Sami and various communities in Siberia), or the capture of animals with pelts and river-fishing, as practiced by numerous Siberian and North Amerindian peoples.
What impact can global warming have on the Arctic societies?
Even though a few managed to undergo an extraordinary socioeconomic transformation during the second half of the 20th century, the Arctic peoples remain closely connected to their polar environment and its ecosystems, whose equilibrium is particularly fragile and vulnerable. To illustrate this fragility, it can be pointed out that lichen, the principal food source for reindeer and caribou, only grow a few millimeters per year.
A significant and long-lasting climate change could greatly disrupt, even threaten, the cultural diversity - and, in certain cases, the very existence - of the Far North's native minorities.
For the time being, the impact of global warming varies according to the region, but the lifestyles of the Arctic peoples have already been affected. "Silaa Nalagavok", "Climate is king": this common saying in Greenland underlines northern man's great dependence on climate.
The hunters of mammals and the traditional fishermen must adapt their activities to major changes linked to the ever-shorter winter, modifications in game-animal behaviour, even the disappearance of certain ancestral resources. The shrinking ice shelf engenders an increasing scarcity of the hunted species (seals and polar bears) which is already perceptible and necessitates an adaptation of hunting practices, in particular the placing of nets beneath the sea ice and the hunting of game in the midst of ice floes. In addition, the thinning ice constitutes a permanent danger for hunters moving about by snowmobile or dog sled.
For their part, the nomadic breeders of reindeer, the Sami and Siberians, dread the hotter summers, which tire out their herds and result in a proliferation of insects. Similarly, they are witnessing greater snowfall in the winter, which disrupts their seasonal migrations and makes it more difficult for the animals to feed.
Finally, on ground that is wet, sudden changes in temperature result in the formation of a layer of ice that is an even more formidable danger for the herbivorous animals.
In a few communities in the north, the warming of the permafrost and the erosion of the coasts and riverbanks threaten the villages, as can already be seen in northeastern Siberia, as well as in northwestern Alaska. The relocation of entire villages is being considered, but the human and financial cost will be too great. For the Siberian communities, already in a very precarious situation since the fall of the Soviet Union, the difficulties are piling up with the recent appearance of these climatic disturbances.
At the political level, the local governments and the organizations that defend the collective rights and interests of the native peoples - such as the Inuit Circumpolar Conference, the Sami Council, the Association of Indigenous Peoples of the North, and the Aleut International Association - are perfectly aware of the environmental problems linked to global warming. They are also aware that the climatic changes rendering their underground resources more accessible are also encouraging an international race for their regions' energy and mineral riches. In fact, requests for the exploration and off-shore exploitation of oil and gas are increasing, while the potential opening of the north Siberian sea route, as well as of the Northwest Passage, is also arousing envy.
What impact will this have on the small societies bordering these sea routes? Will it represent an opportunity for these societies to end their isolation and improve their economic situation, or, on the contrary, will it represent a terrible threat to these peoples' cultures and ways of life, which will not withstand this economic and cultural shock? One must also consider the major ecological risks that this new situation could engender, in particular in the case of an oil spill.
Can the past shed light on the future?
During prehistory, temperature variations provoked major changes in the Arctic cultures, as shown by archeology. This diagram (Fig. 1) compares past climatic changes and the diverse cultures which have succeeded one another in Greenland. In particular, one notices that the beginning of the long period during which this territory remained uninhabited corresponds to the peak in observable cooling, around the year 200 B.C. The presence in Greenland of the Vikings, who arrived from Europe, as well as their disappearance, can also be correlated with the changing climate.
Fig.1- Cultural history of Greenland illustrated in time and space related to climatic change
(fig. H.C. Gullöv, in Grönlands forhistorie , Gyldendal, Köpenhavn 2005, p. 22).
Considering a more recent case, a warming of the sea waters during the first half of the 20 th century had a considerable effect on the activities of the Greenlandic communities, which had previously depended almost entirely upon the hunting of marine mammals. A sudden influx of cod near the coastline had a significant socioeconomic effect on these societies: changes in their activities and lifestyles, the development of urban centres around the fisheries and port installations, and the sedentation and grouping together of settlements that previously had been very widely dispersed (Fig. 2). As a result, more than 80% of the Greenlandic population today lives in town, with a quarter living in the capital, Nuuk. However, this new abundant fish stock turned out to be short-lived. Cod-fishing was therefore replaced by shrimp-fishing, engendering new economic adaptations. Similar observations can be made in Siberia, Alaska and Canada.
Legend:
Differences in temperature (°C)
compared to the average recorded between 1961 and 1990.
Legend: The territory of Greenland.
Fig. 2 - Correspondence between climatic variations and socioeconomic changes.
a/ Evolution of the average temperatures in the Arctic: from the Little Ice Age to contemporary global warming (Diagram: M.-F. André, in Le monde polaire. Mutations et transitions , publisher: Ellipses, Coll. Carrefours, Paris, 2005, p.12).
b/ Evolution of the Greenlandic population and urban growth, from 1950 to 2003.
A large proportion of the Arctic peoples are now part of the modern world. Many of these regions' inhabitants now have salaried jobs, in the administrative sector, the service industry and construction. However, while they are no longer directly dependent upon the resources of their environment for their survival, their ways of living, thinking and governing are still largely based upon the special relationship they continue to maintain with nature - a fundamental link that nourishes the culture and representations of all of these peoples.
Throughout their history, the Arctic peoples have had to face a succession of challenges, most often engendered by climatic changes. It is their exceptional ability to adapt that has allowed certain groups, despite their low numbers, to overcome these crises and survive up until the modern era.
The new episode we are today confronted with will probably have a different impact, because it is combined with the effects of globalization. The survival of these northern peoples no longer depends on their ability to adapt. Indeed, the environmental and geostrategic stakes are now so high that circumpolar cooperation has become indispensable.
This cooperation takes place, in particular, within the framework of the Arctic Council, created in 1996, which gathers together the eight circumpolar countries and the organizations representing the native peoples. Its mandate is to protect the Arctic environment and improve the economic, social and cultural well-being of the Far North's indigenous peoples.
Human and social-science research in the Arctic
While global warming has already had perceptible effects, it is really only after several years of systematic studies among these populations that the trends and conclusions will be able to emerge. Anthropologists and ethnologists are seeking to collect the knowledge of the native peoples, knowledge founded upon a close observation of their environment and its evolution. For this reason, accounts provided by the oldest generations, the inheritors of a long and rich oral tradition, prove to be an extremely valuable source of information.
What's more, research carried out in the fields of archeology and paleogenetics can tell us much about the past of the populations living in the northern regions, so as to better understand the former human and social mechanisms for adapting to the boreal environment. Nevertheless, researchers interested in the future of the Arctic populations don't limit themselves to observing and analyzing the changes engendered by climate warming. They also study demography, economic development at the local and regional levels, the political evolution that goes hand in hand with a strong cultural identity, etc.
In addition to these aspects, one can cite among the subjects studied by the researchers working in these fields:
- the phenomena of family and social destruction affecting these communities often suffering from alcoholism and suicide;
- diet and health confronted with the appearance of new diseases and the effects of chemical pollution on traditional food resources;
- issues related to education and professional training, which condition the emergence or development of a native administration for these territories;
- the analysis of both traditional and recently introduced rituals and beliefs, in particular in Siberia following the collapse of the Soviet Union;
- the study and rescue from oblivion of endangered languages, which has emerged as an obligation in order to preserve our planet's cultural diversity, already greatly impoverished .
Taking into account these various issues, research programmes are now carried out in close cooperation with the concerned communities and involve the participation or training of native researchers.
Therefore, we are today opening up a vast research area. Pursued in an interdisciplinary spirit of international cooperation, its aim is to contribute to the knowledge and preservation of the peoples, ways of life and cultures found in this unique environment that is the Arctic.
Thank you.
E. DEBATE
Bruno ROUGIER
Thank you very much. You can now ask Valérie Masson-Delmotte, Yvon Le Maho and Joëlle Robert-Lamblin your questions, before we move on to a two-part conclusion.
I would like to ask you the first, very simple question: what type of programmes will your teams be working on within the framework of the International Polar Year?
Yvon LE MAHO
I am coordinating a project that I presented to you during my talk. We are monitoring thousands of birds thanks to antenna buried underground. A system has already been installed in Crozet and we plan to install another one in Adélie Land, which unfortunately I cannot take care of myself.
Valérie MASSON-DELMOTTE
We are involved in carrying out small ice corings. Starting in May, we will search for a new deep-sampling site in the northwest of Greenland, with the aim of characterizing the climatic variations over the past 140,000 years, in particular the stability of the last warm period. We are also planning, in partnership with the Glaciology Laboratory in Grenoble, to participate in an Antarctic ice-core study, in up-until-now unexplored regions of the continent.
Joëlle ROBERT-LAMBLIN
I am indirectly involved in a linguistic and ethnolinguistic project to collect native knowledge. The human and social sciences are the poor relation of Arctic research, but a team of young and experienced researchers is working in Greenland, Siberia, Nunavut and Alaska. The resources exist, but organization is lacking.
Bruno ROUGIER
Your greatest wish would be to involve these populations.
Joëlle ROBERT-LAMBLIN
Indeed, the native communities have always collaborated with our research, but we have been endeavoring to train native researchers and to involve them in our work, in order for them to take over from us in a few years time.
From the audience
I would like to know if your interest in these projects is to be explained by their being financed by Prince Albert of Monaco or by a real concern for public health issues. I would also like to understand why Mount Kilimanjaro and Mount Everest, both of which are concerned by climate problems, are not the subject of research.
Valérie MASSON-DELMOTTE
I can only answer your second question. It is true that the Chinese consider Everest the third pole. Numerous studies deal with the future of the glaciers, in particular the tropical glaciers which are essential water sources. Those of Tibet are the subject of studies not lying within the framework of the IPY: certain French teams, such as the Glaciology Laboratory in Grenoble and the Institut de Recherche pour le Développement (Research Institute for Development), are monitoring certain glaciers in Tibet and in the Andes.
Regarding Mount Kilimanjaro, we are analyzing ice brought back by an Austrian team, in order to characterize very recent climate variations. Indeed, the varying volume of its icecap reflects the evolution of its temperature and rainfall, which we are endeavoring to isolate.
However, these two zones do not lie within the framework of the IPY programmes.
From the audience
Allow me to present myself: my name is Jacques Peignon and I have carried out four expeditions by sailboat along the Antarctic Peninsula and around the continent. I would like to know if a programme is planned to clean the waste leftover from the 1958 International Polar Year and if you plan on reducing this type of waste this time around.
Yvon LE MAHO
A programme has been begun by the TAAF, as well as by the Polar Institute. This task will take several years. The work is progressing, but it is very difficult to clean up all the waste in Antarctica.
Bruno ROUGIER
The vestiges of past expeditions can, in the future, serve as testimony.
Yvon LE MAHO
Research is being carried out on the rehabilitation of whaling installations, as well as certain installations for the salvaging of sea-elephant fat.
Bruno ROUGIER
Today, researchers pay more attention to this problem. For example, at the Concordia base, waste water is partially recovered.
Yvon LE MAHO
In addition, everything considered waste is brought back home.
Gérard JUGIE, IPEV Director
Within the framework of the Madrid Protocol, the objective in Antarctica is to achieve zero waste. I would like to point out that the Peninsula, which has welcomed no less than 30,000 tourists and a total of 50,000, is the most visited part of the continent. In their construction of Concordia, France and Italy did everything they could to achieve this objective. For example, 83% of "grey" waste water is treated and then reinjected into the water-use cycle. We go beyond what is required by the Antarctic Treaty, which authorizes the burying of waste. France and Italy have committed themselves to leaving no waste at Concordia.
In addition, as Latin countries, we are carefully watched by the Anglo-Saxon countries, which encourages us to make greater-than-average efforts. I just finished making an inspection tour, in accordance with a clause of the Antarctic Treaty which allows all countries to visit foreign bases. We therefore visited the American South Pole base and Concordia. Both bases are exemplary, insofar as their installation only corresponds to scientific objectives and their waste treatment has been considerably improved. However, we must take into account the fact that, fifty years ago, environmental issues were not given as much importance as they are today.
Bruno ROUGIER
Thank you very much. I would like to know how climate change is affecting the biodiversity of the polar regions.
Yvon LE MAHO
I mentioned the example of Kerguelen's microfauna, by discussing the ability of a fly to establish itself on the island. The number of species is in fact increasing, but these are nonendemic species. We are therefore witnessing a homogenization of the environment, with, for example, the invasion of dandelions, and the disappearance of magnificent landscapes.
Bruno ROUGIER
How far back can we go in climate history?
Valérie MASSON-DELMOTTE
Other climate records, such as marine sediments, can shed light on climate history. Ice provides us with certain elements on the local climate, the composition of both the regional and world atmosphere, via the greenhouse gases. Therefore, we understand what is potentially at stake in going back as far as possible.
Modeling of the Antarctic icecap shows that it is possible to go back more than one million years, perhaps as far back as 1.3 million years, in the driest regions. I pointed out the close relationship between climate and the natural concentration of greenhouse gases.
Up until one million years ago, glaciations occurred every 40,000 years and were of a limited intensity. How did a major change affect the intensity of glaciations? How did the relationship between climate and the carbon cycle play a driving role in this transition? Only by studying the oldest ice will we be able to answer these questions, in particular via the ice samplings carried out at Dome A. Talks are currently underway with our Chinese contacts, for a project to allow us to go back as far as 1.2 million years. Jérôme Chappellaz, present here today, is the French coordinator of this project.
The ice corings are increasingly difficult, because the concerned regions are very far from the bases, which means that various countries must combine their efforts. We can resort to the technology developed for EPICA, along with the know-how of the Glaciology Laboratory in Grenoble.
Bruno ROUGIER
Is climate warming already disrupting the Arctic populations' way of life? Joëlle Robert-Lamblin, you mentioned the danger of the weakening ice for persons moving about by snowmobile, as well as the displacement of certain populations.
Joëlle ROBERT-LAMBLIN
Displacement concerns those villages threatened with destruction by sea storms or the recurring flooding of certain rivers. This is the case on the western coast of Alaska. We're talking about small communities, though they nevertheless have infrastructures which need to be moved. This is a very difficult situation for the populations, especially as it disrupts their hunting and fishing activities, as well as their connection to the land.
From the audience
As part of my work at Météo France, I recently became interested in the problem of the melting ice shelf at the North Pole. I learned that Jean-Louis Etienne, in cooperation with the Wegener Institute, was planning an expedition to measure its depth. How does this project lie within the framework of the International Polar Year?
Bruno ROUGIER
The thickness of the ice shelf will be measured from a Russian-made airship, which should be finished in June or July. The expedition will take place next year.
From the audience
My name is Michel Fily and I'm director of the Glaciology Laboratory in Grenoble. Jean-Claude Gascard directs the DAMOCLES project, which studies the Arctic basin and sea ice. The measurements made by Jean-Louis Etienne can be considered a contribution to this body of work.
Jean-Claude GASCARD
The DAMOCLES project, funded by the European Union, studies the current evolution of the Arctic ice shelf under the effect of the atmosphere and of the ocean. It focuses on ice, though it includes numerous ramifications. The average thickness of the ice has dropped from more than 3 m to less than 2 m in twenty years. 45 laboratories in Europe, including the Alfred-Wegener Institute, are involved in this programme.
It is very difficult to measure the thickness of the ice, in particular due to the presence of ice reefs. Satellites, sonar-equipped submarines, AUVs and floats are all used. We are faced with a logistical problem: it is impossible to carry out this type of measurement using classic means. Helicopters and airplanes have a limited autonomy. That is why Jean-Louis Etienne came up with the idea of carrying out measurements from a sweeping airship, this means of transport having already been used some one hundred years ago in the Arctic.
Today, the thickness of the ice seems to be decreasing by 10 to 15 cm per year in the centre of the Arctic. Maps from the month of September 2006 show rather large areas of open water from the islands of Spitzberg and François-Joseph to near the pole. The forecasting models for ice evolution indicate a certain delay. For example, Tara is drifting twice as rapidly as predicted. These phenomena, which we are endeavouring to understand, could be explained by a fluidification due to the thinning of the ice.
Bruno ROUGIER
Thank you. Yvon Le Maho, during your presentation, you mentioned an antibacterial, the "spheniscine", found in the stomach of the emperor penguin and capable of helping us fight nosocomial diseases. Do you think that we can find useful molecules for research in these a priori inhospitable regions?
Yvon LE MAHO
Each species represents an irreplaceable innovation. The disappearance of any species can therefore represent the loss of a particular molecule. For instance, penguins are particularly sensitive to aspergillosis, caused by the development of a pathogenic fungus in the lungs. This can explain the effectiveness of the protein which we identified, a defensin, in fighting this disease. Defensins have also been discovered in saprophytic fungi, mussels and oysters. The defensin, which possesses a gene one billion years old and which is produced by our body, allows us to fight not only bacteria, but also viruses and pathogenic fungi, as opposed to antibiotics. It therefore represents a very interesting subject for medical research, especially considering that the difficulty once connected to sulphide bridges has just been solved, thereby lowering the cost of molecular production.
The different species also present interesting biological mechanisms: I mentioned that which pushes penguins to once again start feeding. To take another example, Professor Hervé Barré, of the University of Lyon, has shown by studying the penguin's heat-production mechanisms that these birds constitute a better model than laboratory animals, due to their similarities to man.
In parallel with all the genetic strains developed in the laboratory, the study of animal species therefore represents an area of research that is just as interesting, although it currently receives less funding.
Bruno ROUGIER
Valérie Masson-Delmotte, you discussed the role of human activities in global warming. Have you identified other factors?
Valérie MASSON-DELMOTTE
The study of concentrations of greenhouse gases or the temperature of the ice demonstrates man's influence not on the climate, but on the composition of the atmosphere. The tool which allows us to identify the cause and effect is the modeling of interactions between the composition of the atmosphere and the evolution of the climate. By studying polar ice, we have access to several factors that influence climate at different time scales (the Earth's orbit, the frequency of volcanic irruptions, solar activity), but whose global impact remains unknown. It is possible to characterize their past variations in the ice by then using climate models to quantify the cause-effect relationship.
Bruno ROUGIER
Can we quantify the contribution of human activity to global warming?
Valérie MASSON-DELMOTTE
Thanks to climate models, we are capable of asserting that the global warming of the past thirty years cannot be explained by natural factors. In the polar regions, the situation is contrasting. In Greenland, we remained within the natural variability up until some ten years ago, when temperatures began to surpass those of the warm period of the 1930s and 40s, and even those of the climate warmings of the Middle Ages. For the time being, no significant warming has been detected in central Antarctica, but the climate models do not allow us to simulate it. The effects of climate change vary according to the region.
Bruno ROUGIER
Thank you. It is now time for us to close this solemn opening ceremony for the International Polar Year with two speeches. The first speaker will be François Goulard, Minister for Higher Education and Research.