Heaven and Earth from Pergamon to Potsdam

Heaven and Earth From Pergamon to Potsdam

Potsdam Institute for Climate Impact Research Imprint

Published by: Potsdam Institute for Climate Impact Research (PIK) Telegraphenberg A31, 14473 Potsdam, Germany www.pik-potsdam.de

PIK is a Member of the Leibniz Association

Editors: Margret Boysen & Hans Joachim Schellnhuber

Text: p. 5, 7, 15, 29, and orange figure captions: Margret Boysen; p. 25/26: Ottmar Edenhofer; Contents p. 17: Friedrich-Wilhelm Gerstengarbe; p. 21: Hermann Held; p. 11, 12, 18: Stefan Rahmstorf; 5 From Pergamon to Potsdam p. 8: Chris Rapley; p. 23: Hans Joachim Schellnhuber 7 The Potsdam Institute for Climate Impact Research (PIK) 8 An Outside View – by Chris Rapley Translation: Christopher Hay (except p. 5, 8, 23) 11 Global Warming 12 Modelling the Past and Future Climate Photos and Illustrations / Copyright: 15 Gradual Change – Cumulative Impacts Photos: Johannis Laurentius / Pergamon Museum Berlin, 17 Climate Change in the Brandenburg Region except p. 6 (Jörg P. Anders); p. 27 (unknown); 18 Storm Gods p. 28 (Jochen Remmer) / bpk / Antikensammmlung, SMB. 21 Systemic Change Illustrations: PIK 22 World Map of Tipping Elements 25 Why Solving the Climate Problem Does Not Cost the Earth Further Contributions by: 29 Sustainability Research Rupert Klein; Jürgen Kropp; Kai Leßmann; 30 Selected References Wolfgang Lucht; Till Sterzel

Layout: www.polyform-net.de

Second Edition, Copyright May 2007 PIK 5

From Pergamon to Potsdam The triumph of civilization over the volatile forces of nature, allegorized on the frieze of the Pergamon Altar as the battle between the Olympian gods and the sons of the Earth mother Gaia, today turns out to have been a Pyrrhic victory: The powerful tools of progress, forged during the Industrial Revolution 250 years ago, evoked forces which are beginning to slip out of control. In particular, the unbridled burning of fossil fuels and the so-induced global warming jeopardize the essential life-support systems of humanity. In this way the giants – Gaia’s offspring – are returning wilder and more irritable than ever, like monstrous hurricanes which can charge themselves with energy from heated ocean surfaces. Zeus, the champion of civilization, and the other Olympians, must act quickly to reach an agreement with Gaia, The Pergamon Altar if the face of Earth is to be healed again. Sculpted around 170 BC in western Asia Minor and smashed to pieces several centuries later, In the ancient struggle, Athena – the goddess of science and wisdom – the Pergamon Altar was rediscovered in the ignored Gaia as she pleaded for the lives of her sons. Today she knows that 19th century and reconstructed in Berlin with an ultimate victory is unattainable. A lasting, sustainable peace may be the Turkey’s permission. The Hellenic masterpiece best that can be achieved. Thus Athena cannot afford to balk; she must use depicts on a life-sized marble frieze more than 100 metres long the mythic tale of the her entire intelligence to establish a just world order – a place where the giants victorious struggle of gods against chaos and of nature can assume their proper place. the forces of nature – the Gigantomachy. The Potsdam Institute for Climate Impact Research strives to aid the goddess of Science in this enormous task. 7

The Potsdam Institute for Climate Impact Research (PIK)

From the outset, the aim of those working on dependent than any of the problems which As every modern child knows, it is not Atlas Potsdam’s Telegrafenberg hilltop was to reveal humankind has already failed to address. who bears the celestial or terrestrial spheres, and explore the invisible, the unseen. In 1879, The climate problem can only be solved but physics. There is no Greek demigod holding the world’s first astrophysical observatory through a general transition to global sustain- up the Earth; the Earth holds us. But human- was established here in what is now the head- ability. In order to identify and address all its kind must start to shape nature in a way which quarters of the Potsdam Institute for Climate key aspects, the Potsdam Institute’s scientific sustains its essence. Why should an appar- Impact Research (PIK). The beautiful build- activities are organized into four main research ently slight global temperature increase of just ing’s three domes were studded with powerful domains: 1–2°C have such significant implications for telescopes capable of detecting even the most Earth System Analysis is the prerequisite our planet, and why would it be fatal to allow distant stars in the depths of the night sky. Yet for a better understanding of the climate the Earth’s temperatures to climb even higher? even then, the scientists who worked here were machinery. Climate Impacts and Vulnerabilities These and other questions are answered in not only concerned with the heavenly firma- are crucial topics in assessing the susceptibility this brochure. Solving the problem of climate ment; the sun and its relationship to the global of nature and human society to the impacts of change may well require efforts worthy of Atlas climate were also a keen focus of their interest. climate change. Sustainable Solutions need to himself – and will certainly require us to think The research undertaken by the Potsdam demonstrate how global warming can be lim- on that scale. The Potsdam Institute, with just Institute for Climate Impact Research contin- ited to a manageable scale and how social adap- 150 staff, is striving to make a cognitive contri- ues this tradition of scientific exploration. But tation can be promoted, while Transdisciplinary bution to the solution of this planetary task. today, it is not the stars which are the subject Concepts and Methods unite specialized fields of of the researchers’ scientific curiosity: the study, knowledge and practice for the advance- Atlas sided with his fellow giants in the war against problem has moved much closer to home. ment of outcome-oriented approaches. the Olympians. In return Zeus condemned Atlas Human-induced global warming poses one of It is no exaggeration to say that the genu- to stand at the western edge of the Earth and hold up the greatest challenges to humankind in the ine cooperation between natural and social the sky on his shoulders to separate the spheres. 21st century. The climatic change projected for scientists at the Potsdam Institute is viewed A popular misinterpretation is that Atlas had to hold industrial business-as-usual can disrupt our as a model to be emulated worldwide. This is up the Earth’s globe. planet’s natural and social habitats and even has both an incentive and a burden. The fact is that the potential to change the overall dynamics and if we are to master the challenges of climate character of the Earth System. The challenges change, dozens of institutes like PIK need to be facing us are more complex, diverse and inter- established around the world. 8

Chris Rapley Director of the British Antarctic Survey

An Outside View

Unfortunately, the small-scale and increasingly It is a pity, then, that carbon dioxide is an essential given the distribution of key experts Gaia, the peaceful Greek goddess, urban perspective of our daily lives makes it odourless gas that has no link with ionizing worldwide. However, a powerful adjunct is to personified the Earth. She gave birth to hard for us to appreciate that we are, collec- radiation. Had it been otherwise, humans assemble an appropriate mix of bright minds the giants, also known as Titans. In tively, hurting the planet. We do so through might have been more circumspect about under a single roof, guided by a single purpose, the Titanomachy depicted at Pergamon, what Samuel Butler observed is the “ineluc- releasing some 1000 billion tons of carbon and unfettered by distractions. she implores Athena not to separate table desire of every organism to live beyond dioxide into the atmosphere through the burn- Such is the nature of the Potsdam Institute her from her son Alkyoneus, who is its means”. In this endeavour we have not yet ing of fossil fuels. The consequence is increas- for Climate Impact Research. Only established mortal without her. reached the limits of our needs for material ingly evident: climatic change on a scale which 15 years ago, it is already pre-eminent in its resources, but we are reaching the environ- threatens to transform the planet, damaging field. The outcomes of its work are described in mental limits of our waste products. human society and the global economy – this document, which I commend to the reader, This is not the first time that humans have unless strong international measures are taken who, I assert, cannot fail to be impressed by confronted such a problem. In the mid-nine- to reduce emissions quickly. PIK’s contributions to help humanity (in the teenth century, when London was the world’s How can this be achieved? Without Olym- words of its Director) “Avoid the Unmanage- largest metropolis, the discharge of sewage pian omniscience and authority to guide human able and Manage the Unavoidable”. into the river Thames resulted in such an actions, we must rely on a political process intolerable smell that Government action underpinned by evidence from science. became necessary. Institutional impediments But the Earth is (as far as we are aware) were overcome to achieve a technological solu- the most complex object in the Universe, and tion – the construction of the Victorian unified understanding how it functions presents the sewage system. science community with a daunting challenge. Similarly, when it became apparent in New approaches and practices are necessary, the mid-1980s that the release of industrial including the creation of interdisciplinary chemicals, mainly in the northern hemisphere, teams, an emphasis on synthesis, and a recog- had created the Antarctic ozone hole, with an nition that the practitioners of “Earth System associated skin cancer threat to animals and Science” must interact at an unprecedented humans alike, a combination of technology level with society at large. and internationally agreed curbs on behaviour Progress is possible through the efforts of provided the solution. geographically dispersed teams. Indeed, this is Emissions [GtC] 35

30 100% Temperature Change (°C) 0,6 11 25 80% 0,4 Temperate Grass Tropical Grass 20 60% 0,2 15 Emissions Reduction 40 % 0 10 Summergreen Trees Progression of globally averaged surface tem- Raingreen peratures based on data sets from NASA (red) 5 20 % Trees -0,2 and the Hadley Centre (black). The figure Barren 0 0% shows annual values and the overall trend. -0,4 2000 2020 2040 2060 2080 2100 Years 1900 1950 2000 2050 2100 Years

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Global Warming

Fishery Mana g em en t Our planet is in the initial stages of dramatic as environmental history shows. The Potsdam temperature difference between an ice age Council Authority climate change. Records show that since 1900, Institute is a major player in tracing this history, and an interglacial episode. However, as we globally averaged surface temperatures have producing numerous publications to interna- are already in a natural period of interglacial Scientific Fishing Firm increased by 0.8°C (see figure). Around the globe, tional acclaim. Carbon dioxide traps solar radia- warming at present, we should really call the Institution Group 1 Yield: mountain glaciers are retreating, and Arctic sea tion which would otherwise escape into space human-induced era ahead of us the “fire age” Chan g e o f ice cover has shrunk by 20 per cent in recent dec- and directs some of it back towards the Earth’s or “hot period”. According to current scientific Fish Stock ˙ ades. The margins of the Greenland and Antarctic surface. Thus in combination with several other thinking, this dangerous climate change must Other continental ice sheets now show signs of disin- gases, it forms a warming cocoon around our be avoided at all costs, and global warming Species Fishing Firm tegration. Global sea levels have already risen by planet which, without this greenhouse effect, must be limited to a maximum of 2°C relative Group 2 Other Yield: 20 cm in the 20th century, and satellite altim- would be too cold to sustain life. In climate his- to the pre-industrial value. This will ultimately Species etry shows that they are currently soaring by tory, CO2 concentration has generally changed require a transition to a carbon-free society 3 cm per decade. only gradually over the course of many mil- worldwide before the end of this century. The There has been a broad consensus within lennia, following geological cycles. But like Potsdam Institute is developing detailed strat- Energy efficien c y the international research community for many Prometheus who stole fire from the hearth of egies for the implementation of this transition

years that the observed global warming is Zeus, humankindR en e wable Ener gies has seized control of this (see p. 25). predominantly due to human activity. The carbon cycle, with the result that every year, we Carbon Capture & Storage primary cause is the rise in atmospheric CO2 are currently extracting the same quantity of concentration to its current level of 380 ppm. fossil fuels from the Earth as were formed over

Today’s atmospheric CO2 levels are the high- a period of around one 0million100 years.200 300 400 500 600 700 800 [GtC] est for millions of years – before the Industrial The latest climate trends offer a bitter Prometheus, one of the giants, was a Revolution, the level was just 270 ppm! These foretaste of the future: the last ten years were

friendly trickster and was also considered a CO2 emissions are caused by the burning of fos- the warmest decade for many centuries and god of fire. He stole it from Zeus, who had sil fuels such as coal, oil and gas, and by agri- subjected us to new types of extreme weather hidden the flames from man. The Greek poet culture and deforestation. 56 per cent of the conditions. If we adopt a “business as usual”

Hesiod relates in his tale that Zeus had him CO2 emitted by human activities is still present approach and take no action to curb green- chained in revenge. The giant shown here in the atmosphere. house gas emissions, the temperature of gazes up at Zeus, who has struck him down Carbon dioxide has always played an the Earth’s atmosphere could increase by with a bolt of lightning. important role in the Earth’s climatic processes, another 5°C by 2100. This is equivalent to the

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30 100% Temperature Change (°C) 0,6 25 80% 0,4 Temperate Grass Tropical Grass 20 60% 0,2 15 Emissions Reduction 40 % 0 10 Summergreen Trees Raingreen 5 20 % Trees -0,2 Barren 0 0% -0,4 2000 2020 2040 2060 2080 2100 Years 1900 1950 2000 2050 2100 Years

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12 Simulation of ice cover over North America during the last interglacial about 20.000 years 4000 ago. The figure shows a Heinrich Event, involv- ing a large-scale surge of ice from the Great 2000 Laurentian Ice Sheet into the Atlantic Ocean. Longitu d e 0 -160 gradually increasing forcing -140 -120 -100 80 Latitu d e 70 -80 60 super-critical state -60 50 40 -40 30 sub-critical state -20 20 N

Modelling the Past and Future Climate

The Potsdam Institute develops and runs which cannot possibly be carried out using a carbon cycle, are being integrated into the global and regional climate models. With its pencil and paper. models. By comparing the results achieved global models, it simulates the Earth’s long- Through computer simulations, experi- from the application of the models with term climate, while its high-resolution models ments can be conducted which scientists can- observed data, scientists can learn more about are primarily intended to show the implications not, or should not, perform in the real world. the natural mechanisms of climate change. of climate change for Europe and especially For example, they can model different scenarios This subjects the models to challenging tests.

for vulnerable regions. The Potsdam Institute to study the effects of various CO2 concentra- The Potsdam Institute recently undertook a has established a worldwide reputation for tions in the atmosphere. This enables them to systematic comparison of data from the last testing its climate models against relevant develop projections using the “if... then” prin- ice age with a large number of models in order

phenomena in the Earth’s history. This is pos- ciple: if humankind emits a certain amount of to ascertain the climate’s sensitivity to CO2 sible because information about past epochs carbon dioxide (or other gases), then the fol- forcing. The study confirms that the climate 4000 is contained in numerous natural “climate 4000lowing climatic changes (temperature increase, system can indeed be massively disrupted 2000 archives” – ice that is hundreds of thousands 2000sea-level rise, etc.) are likely to occur. by human activity and that effective counter- Longitude 0 of years old, fossilized air bubbles, tree ringsLongitude 0 The opposite question that we can ask is measures must be taken within the next one -160 -160 and deposits in the seabed. Among other this: which volume of climate-relevant gases or two decades. -140 -140 -120 things, the Potsdam Institute undertook the can we still allow-120 ourselves to emit without -100 first-ever simulation of the climate80 Latitude of the last jeopardizing the target-100 which the European 80 Latitude 70 70 -80 ice age (20,000 years 60ago) using an ocean- Union has set itself, namely-80 to limit global 60 -60 50 -60 50 atmosphere model.40 warming to a maximum of 2°C relative to the 40 -40 Climate models30 are algorithms which con- pre-industrial value? The answer is that-40 global 30 -20 20 -20 20 tain concentrated information about physi- greenhouse gas emissions must be reduced by cal correlations in the form of equations. For at least 50 per cent by 2050. Zeus, father of the Olympian gods and example, they may contain equations which Although a model can simulate the over- ruler of the weather, is shown while hurling calculate temperatures, winds and ocean cur- all climate system very effectively, not all the lightning bolts against his enemies. Accor- rents. Ideally, these models are run on parallel feedback mechanisms between the various ding to Hesiod, Zeus created Pandora as the computers to enable the many different equa- subsystems are properly understood yet. How- price of fire and a punishment for mankind. tions to be worked out simultaneously for many ever, more and more components, such as the She took the lid off the jar she carried diverse points around the globe – calculations continental ice sheets, the biosphere and the and evils, hard labour and disease flew out. Emissions [GtC] 35

30 Temperature Change (°C) 0,6 Klotho, one of the three Moirae (and 100% Shifts in the vegetation composition of a highland 15 25 savannah in southern Africa under climate change. goddesses of human fate), is hurling a 80% 0,4 Temperate Grass Tropical Grass The far-reaching exchange of underlying ecosystems snake-filled vase at her opponent, a violent 20 will also have socioeconomic and cultural consequences. 60% 0,2 son of the Earth. Even Zeus was unable 15 to interfere with the Moirae. Emissions Reduction 40 % 0 10 Summergreen Trees Raingreen 5 20 % Trees -0,2 Barren 0 0% -0,4 2000 2020 2040 2060 2080 2100 Years 1900 1950 2000 2050 2100 Years

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Gradual Change – Cumulative Impacts

Fishery Mana g em en t Council Authority Globally averaged surface temperatures have trajectory of low-pressure areas or the fre- Some physiographic regions – such as perma- increased by around 1°C since the start of quency of certain large-scale weather systems frost zones – are directly struck by rising tem- the Industrial Revolution – and the impacts and thus affect the distribution of precipita- peratures; others are affected indirectly. Many Scientific Fishing Firm Institution Group 1 are now gradually becoming visible. Human- tion. Long-lasting fine weather conditions ecosystems offer benefits such as timber or Yield: induced climate change is quite clearly a result in periods of drought, whereas air which food to human communities, while preserv- Chan g e o f Fish Stock gamble with a massive Pandora’s box. At a tem- is saturated with water vapour and charged ing others is desirable due to their beauty and ˙ perature increase of 1°C, its lid is slightly ajar. with energy causes severe weather conditions, diversity. However, some also serve an impor- Other An increase of 2°C releases many of its harmful with torrential rainfall and storms. One and the tant function in the Earth System, notably the Species Fishing Firm Group 2 climate impacts, and far beyond this margin, same region can thus be adversely affected by tropical rainforests with their influence on the Other Yield: nothing can restrain its potent contents. floods alternating with water scarcity, making global hydrological cycle. In its studies, the Species It is possible to postulate temperatures at it increasingly difficult to plan agricultural pro- Potsdam Institute has shown, in particular, which a specific ecosystem suffers significant duction, for example. that the Amazon rainforest and the northern harm or collapses. A further 1°C increase in glo- The implications of climate change vary taiga are likely to respond to global warming Energy efficien c y bal warming, for example, is likely to result in very significantly according to natural and social by releasing massive amounts of carbon diox- the dieback of the tropical coral reefs, as it will conditions. For example, more than one billion ide, further accelerating the process of climate R en e wable Energies make the sea-water too warm, too deep and people already living in semi-arid zones will be change. In other words, global threats could Carbon Capture & Storage too acidic. Although continents and oceans impacted severely by food and water scarcity. In result from ecosystem change as well. respond slowly to rising temperatures com- the industrialized nations which import most of So will climate change cause severe disad- pared with human beings, the rise would still their food, periods of drought will occur in the vantages or perhaps even offer fresh opportu- 0 100 200 300 400 500 600 700 800 [GtC] be much too fast for most habitats to adapt. form of “heat waves”, leading to an increase in nities? To answer this question, every region Climate change warms the world un- the number of forest fires, water scarcity and, in and sector must be considered individually. equally: in some regions, the rise will amount extreme cases, more deaths as a result of heat Vulnerability does not only depend on the to three times the mean value, whereas in oth- stress. These affluent countries will also have to type of habitat but also on whether adaptation ers, it will remain below the globally averaged accommodate increasing numbers of environ- is technically and economically feasible. The surface temperature. The regional character mental migrants – including refugees from sea- adaptive capacity of poor countries and low- of the climate is also strongly dependent on level rise whose homes are submerging, and lying island states is obviously minimal, and atmospheric and oceanic circulation – changes war refugees displaced by violent conflicts over this is likely to further widen the North-South in these dynamic patterns may modify the increasingly scarce environmental resources. divide. 4000 2000

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30 100% Temperature Change (°C) 0,6 25 80% 0,4 Temperate Grass Tropical Grass 20 60% 0,2 15 16 Demeter was worshipped as the Emissions Reduction Precipitation change for the Brandenburg 40 % region in the decade 2046 to 2055 relative to 0 goddess of fertility, harvest and health. 10 Summergreen Trees Raingreen the period 1951 to 2003 related to the emission When her daughter disappeared, the 20 % 5 Trees scenario A1B (business-as-usual). The black -0,2 distress of Demeter caused a famine.Emission s [GtC] 35 Barren dots are weather stations. 0 0% -0,4 On the frieze, Demeter survived only in 30 2000 2020 2040 2060 2080 2100 Years 1900 1950 2000 2050 2100 Years 100% Temperature Change (°C) 0,6 fragments. There she fights with two 25 1880 1900 1920 1940 1960 1980 2000 Years torches against the giants. 80% -10 -20 -30 -40 -50 -60 0,differ4 ence (mm) Temperate Grass Tropical Grass 20 60% 0,2 15 Emissions Reduction 40 % 0 10 Summergreen Trees Raingreen 5 20 % Trees -0,2 Barren 0 0% Fishery Mana g em en t -0,4 2000 2020 2040 2060 2080 2100 Years Council 1900 1950Authority 2000 2050 2100 Years Climate Change in the Brandenburg Region1880 1900 1920 1940 1960 1980 2000 Years -10 -20 -30 -40 -50 -60 difference (mm) Scientific Fishing Firm Institution Group 1 Climate change will affect individual landscapes crop yields can be expected. There is a very Yield: Chan g e o f first of all, both in a positive and a negative significant risk to the region’s forests – mainly Fish Stock ˙ sense. As the harmful impacts will in most cases conifers – from greater heat stress, forest fires clearly predominate, they must be identified, and pests. People will also face growing health Other Species Fishing Firm their scale estimated, and appropriate adapta- risks from longer-lasting heat waves in future, Fishery Mana g em en t Group 2 tion strategies devised. Relevant procedures especially in the Berlin conurbations. Council Authority Other Yield: Species and methodologies have been developed at Despite – or indeed because of – these clear the Potsdam Institute for this purpose and warning signals, there is a chance to take Scientific Fishing Firm Institution Group 1 are now being deployed for global analyses as appropriate action. To this end, the Institute is Yield: well. developing adaptation strategies which can Energy efficien c y Chan g e o f Brandenburg – the Institute’s home region, be implemented by decision-makers, and is Fish Stock R en e wable Energies ˙ with its headquarters located in the capital underpinning these with specific recommen- Other Potsdam – was the first region to be subjected dations for action. For example, plans for Carbon Capture & Storage Species Fishing Firm to such analysis. Based on various IPCC scenar- the further regulation of the Elbe have been Group 2 Other Yield: ios, a regional climate model provided data and shelved due to the low water levels expected Species offered conclusions about the climate trends in the summer months. The Brandenburg 0 100 200 300 400 500 600 700 800 [GtC] which can be expected here in future. The key Government has also agreed a forest conver- finding is that a temperature increase of just sion programme to replace the coniferous Energy efficien c y 1.4°C in the next 50 years is likely to result in monoculture with better-adapted species.

a significant reduction in precipitation, espe- Drainage of agricultural areas is being Rreduced en e wable Energies cially in the summer months. Therefore, using in order to minimize surface runoff in favour of a hydrological model, water availability was infiltration. A heat warning systemCarbon for theCaptur Bere -& Storage estimated. The findings are worrying: although lin area is under discussion. Further preventive

Brandenburg has more lakes than any other measures are being planned, and the Potsdam 0 100 200 300 400 500 600 700 800 [GtC]

Largest per capita CO2 emitters Countries most vulnerable to climate change (red) versus area in Germany, a negative hydrological bal- Institute is actively contributing its expertise Highest social and /or agro-economic vulnerability countries contributing most to global warming through the highest ance must be anticipated in the long4000 term, and to facilitate their implementation. Largest per capita CO emitters, and highest social and /or agro-economic vulnerability cumulated CO emissions per capita (1950–2003, dark grey). 2 2 this will impact accordingly on 2000 the region’s Low or moderate both in per capita CO2 emissions and social and / or Hatching indicates countries that belong to both groups. agro-economic vulnerability ecology and agriculture. MarkedLongitu d e decline0 in -160 gradually increasing forcing -140 -120 -100 80 Latitu d e 70 -80 60 super-critical state -60 50 40 -40 30 sub-critical state 4000 -20 20 N 2000

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Fishery Mana g em en t Council Authority

18 Typical vortex diameters and wind velocities Scientific Fishing Firm Institution Group 1 for hurricanes and their siblings. Mathematicians at PIK decompose these differing scales Yield: Chan g e o f analytically by means of limit analyses for Fish Stock vanishing order-of-magnitude parameters e. ˙

Other Species Fishing Firm Group 2 The Winds as represented in Greek mytho- Other Yield: Species logy by four winged horses, belong to Zeus, the god of weather. On the side of the giants fought Maimaches, the “storm-man”, whose

Energy efficien c y name is evocative of Maimakterion, the month of autumn gales in Attika. Hurricanes were R en e wable Energies certainly not known to the Greeks; their name derived from the Mayan wind-god Hurakan. Storm Gods Carbon Capture & Storage

Some of the most awe-inspiring phenomena sure in0 its100 eye 200– 882300 millibars400 500 – 600that 700was the800 [GtC]where the best measurement data exist, this in our climate system are the powerful storms lowest ever recorded in such a storm. link is well-documented. The increase in hur- which, under certain conditions, form over the So an urgent question for climate research ricane force has indeed kept pace with rising tropical seas. In the Caribbean, these storms is whether human activities and the resultant temperatures and has reached record levels are named “hurricanes”, after Hurakan, the global warming could be increasing the inten- here in recent decades. Similar increases have Mayan god of winds. In the Pacific, they are sity of these hurricanes, making them even been observed in other ocean basins as well, known as “typhoons”. If they make landfall, more dangerous than ever. There is some justi- but there is still some doubt about the quality these tropical storms are capable of wreaking fication to this concern. Scientists have recog- of these data. devastation on a massive scale – through high nized for many years that the source of energy When it comes to predicting future trends winds, storm surges and torrential rainfall. As that powers these storms is the warm water relating to the force of tropical storms, the 4000 examples of their destructive power, we need in the oceans: that’s why they only form over large-scale climate models still lack the resolu- 2000 only think of Hurricane Katrina, which ravaged waters with a minimum temperature of 26.5°C, tion needed to give accurate forecasts. For that Longitu d e 0 the city of New Orleans in August 2005, and and why their intensity rapidly drops back to reason, PIK is developing asymptotic methods -160 gradually increasing forcing Super Typhoon Saomai, which inflicted mas- that of a normal cyclone once they have made in order to improve our understanding of the -140 -120 sive damage in China in August 2006. landfall. The fact that these storms swell over physical correlations. The fact that the vortex -100 New hurricane80 Latitu d erecords have been pil- warm water and die down over colder seas is core of tropical storms is almost axially sym- 70 -80 ing up60 in recent years. In 2004, a hurricane key information for scientists forecasting and metric provides vital clues in this context. super-critical state -60 formed50 in the South Atlantic – an all-time first, tracking the progress of hurricanes on a daily With these new methodologies, PIK’s aim is to 40 -40 30 sub-critical state although a British climate model had predicted basis. achieve better simulation of these storms, first -20 20 N that there could be hurricanes in this region in Over the last 100 years, the surface tem- in weather forecasting, then also in climate future as a result of global warming. The same peratures of the world’s oceans have risen by models. year, Japan was hit by ten typhoons in a sin- 0.6°C. This has occurred in parallel to the rise gle season for the first time. The 2005 North in air temperatures and has the same cause: Atlantic hurricane season was the most active the accumulation of greenhouse gases in the since records began in 1851, with thirteen hur- atmosphere. The tropical seas are no exception. ricanes in one year. That same year, Hurricane It is therefore logical to assume that this warm- Vince moved toward the coast of Spain, while ing of the water has increased the intensity of Hurricane Wilma showed a minimum air pres- tropical storms. Indeed, for the North Atlantic,

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A system’s distance from a tipping point can be 21 determined through the character of its natural 4000 fluctuations. This analysis is based on the funda- mental insight that sluggish excursions from 2000 equilibrium increase disproportionatelyLon as gittheu d e 0 system moves towards a critical threshold under -160 gradually increasing forcing gradually increasing forcing. The potential on the -140 right becomes shallower and finally vanishes. -120 -100 80 Latitu d e 70 -80 60 super-critical state -60 50 40 -40 30 sub-critical state -20 20 N

Systemic Change – Tipping Points

When Poseidon, the god of the sea, was angry, ness depends on the system concerned: for impede deep water formation in the North he would lash the sea into fury with his trident. example, the boiling point of water is reached Atlantic Ocean and result in a shutdown or The seafarers of antiquity were often caught within seconds, political revolutions may take slowdown of the thermohaline circulation unawares by the unleashed forces of nature to days or weeks, while the timescale in the Earth there. Another dangerous consequence would which they were helplessly exposed. Thanks System ranges from a few years to centuries. be shifts of precipitation in the tropical belt. to modern weather forecasting, the surprise Atmospheric and land-use changes may result The Tibetan plateau could become snow-free, element of these phenomena has largely disin the Indian monsoon becoming unpredict- leading to floods in the short term and water appeared, but Poseidon’s trident can still jolt able – but the region‘s agriculture and thus the scarcity in Central Asia in the long term. Glo- the mechanisms of the Earth System in a way food security of a billion people depend upon bal warming would also be likely to speed up which is beyond our comprehension. Indeed, it occurring regularly. The depletion of the pro- the disintegration of the Greenland and West

we are provoking the “climate gods”, awaken- tective ozone layer over Europe and the Antarc4000- Antarctic ice sheets. Complete melting of the 4000 ing giants, without even realizing it. Perhaps we tic, which is exacerbated by global warming,2000 Greenland ice would result in a 7 m sea-level 2000

can solve the conundrum by asking a question. also takes place within this timescale. Longitude 0 rise. Longitude 0 What do the following have in common: water The impacts which could occur over a -160 Most of these effects (see world map, -160 heated to boiling point, a lake which is tipping timescale of years and decades include, for p. 22)-140 have not been adequately considered in -140 into eutrophication, and the French Revolu- example, the emergence of a permanent “El analyses -120of how much global warming we can -120 -100 80 Latitude -100 80 Latitude tion? The answer is that in all three cases, a Niño”. At present, this climatic caprice, with still afford. Their common feature – namely 70 70 -80 60 -80 60 system property changes abruptly in response its extreme weather conditions, inflicts suf- that they are likely to occur-60 abruptly and/or irre- 50 -60 50 to a steady forcing: the cooker applies constant fering upon the South American population versibly as a result of global warming – presents 40 40 -40 30 -40 30 heat; the local community perpetually pipes its every four years or so. Over a similar timescale, climate policy with even greater -20 challenges20 -20 20 untreated sewage into the lake; and the French the possible dieback of the Amazon rainforest than the climate impacts which occur gradu- Poseidon was the god of the sea and the bourgeoisie becomes more economically pow- would result in massive loss of its unique bio- ally. On the other hand, some of the switches water in general. In the battle depicted in erful while developing its claim to political diversity and further accelerate the process of mentioned above have properties which make Pergamon he emerged – as one can reconstruct codetermination under the incessant influence global warming. risk assessment easier (see figure) and enable from the heavily fragmented frieze – from the of Enlightenment philosophy. The most dangerous phenomena which are early warning systems to be developed. waves in a chariot drawn by powerful seahorses. In the same way, climatic properties of likely to occur over decades or centuries include entire subcontinents could “tip” as a result changes in ocean currents and ice melt. For of global warming. Here, the level of abrupt- example, human-induced climate change could Potential Anthropogenic Tipping Elements in the Earth System 3 Methane Escape from Thawing Permafrost 6 Climatic Change-Induced Ozone Hole 10 West African Monsoon Shift fixed organisms, such as plankton algae and Regions and Continental Shelves over Northern Europe The West African monsoon is affected both corals, in building their skeletons, which Huge amounts of methane, which is a Particularly Northern Europe could face a by heavy deforestation in coastal areas bind carbon. Time Frame: unknown. 1 highly potent greenhouse gas, could be climate change-induced ozone hole. Global and increasing sea-surface temperatures. 2 released by global warming. On the one warming at the bottom of atmospheric strata The future of this monsoon system is still 14 Suppression of Antarctic Deep Water 5 3 hand, terrestric methane will emanate implies cooling in the stratospheric “roof ”. uncertain. Global warming may bring about Formation and Nutrients Upwelling 3 from thawing permafrost areas in Siberia This cooling induces ice cloud formation a doubling of dry years in the Sahel by the Similar to the North Atlantic, convection 5 6 4 and Northern America. On the other hand, which in turn provides a catalyst for ozone end of the century or a complete monsoon of water masses in the Southern ocean can 4 ‘methane ice’ assembled by natural proc- destruction. Time Frame: ~10 –1000 yr. collapse, both of which would have pro- be suppressed by freshwater inflow from esses over millions of years off many coasts found large-scale impacts. Time Frame: melting ice. If there is a critical threshold, might be activated by changing ocean 7 Darkening of the Tibetan Plateau ~ 50 –100 yr. it has not been assessed so far. The result- temperatures and currents. Time Frame: As the snow cover of the Tibetan territory ing decline of nutrients would reduce phy- 7 ~ 1000 yr. melts due to global warming, the exposed 11 Dieback of Amazon Rainforest toplankton and krill, which marks the basis dark rock surface will amplify regional A large fraction of precipitation in the Ama- of the marine food chain. Time Frame: 8 4 Boreal Forest Dieback warming through increased absorption of zon basin is recycled evaporation water. The ~ 100 yr ? 9 Northern boreal forests account for almost solar radiation. As a side effect, the fresh- reduction of regional rainfall in a warming one third of the global forest inventory. They water supply for many Asian countries, climate, intimately connected to El Niño/ 15 Collapse of the West Antarctic Ice Sheet 10 are declining in a warming climate because which depend on glacier melt water, will Southern Oscillation, as well as forest frag- Although assumed to be not as vulnerable of enhanced disturbance stress through be reduced. Moreover, it is possible that mentation due to human activity could bring as the Greenland Ice Sheet, a collapse of the 13 12 tipped already bereits gekippt fires, pests, and storms. At the same time, the darkening of the Tibetan plateau could the forest cover to a critical threshold. Ama- West Antarctic Ice Sheet could be initiated 11 their regenerative capabilities are dimin- affect the Indian monsoon system. Time zon dieback would have profound influence within this century. Warming oceans result in limbo auf der Kippe ished by temperature and water stress as Frame: ~ 50 – 100 yr. on the global climate and at the same time in melting of offshore ice shelves, which still stable noch stabil well as direct human interference (logging, result in a huge loss of biodiversity. Time currently impede the out-flow of the con- fragmentation, etc.). The dieback would 8 Disruption of Indian Monsoon Frame: ~ 50 –100 yr. tinental ice masses behind. Furthermore, trigger massive release of carbon dioxide, Up to 90% of India’s precipitation is pro- the warm water could be undercutting the which in turn enhances climate change, as vided by the regular summer monsoon. 12 Change in Southern Pacific ice sheet and yield further separation from well as significant losses in biodiversity. Carbon dioxide as well as aerosols play a key Climate Oscillation the bedrock, thus accelerating the decay. Time Frame: ~ 50 –100 yr. role in this highly variable system. Air pollu- Although uncertainties are large, some cli- The complete ice sheet collapse would tion, land-cover change and greenhouse gas mate models predict an increased frequency raise the global sea level by 4– 5 m. Time 2007 14 5 Suppression of Atlantic Deep Water emissions could bring about a roller-coaster and/or intensity of El Niño conditions in Frame: ~ 300 –1000 yr. 15 16 Formation succession of intensified and weakened the Southern Pacific. The impacts of such Schellnhuber © The warm Atlantic surface ocean current is monsoons in South Asia causing extreme a change in the oceanic oscillation patterns 16 Antarctic Ozone Hole responsible for the benign climate in North- droughts and floods.Time Frame: 30 –100 yr. would be felt around the globe, especially Already strongly perturbed by humanity’s western Europe. This great ‘conveyor belt’ in the form of droughts in South-East Asia emissions of chlorofluorocarbons in the tipped already bereits gekippt 1 Arctic Sea Ice Loss 2 Melting of Greenland Ice Sheet is ultimately driven by cold and dense water 9 Re-Greening of the Sahara and and many other regions. Time Frame: Rapid past, the protective ozone layer is believed

in limbo auf der Kippe As sea ice melts in a warming climate, it Greenland’s ice sheet is melting due to the sinking to the bottom of the North Atlantic Sealing of Dust Sources changes possible in 10 – 100 yr. to be regenerating after these chemicals exposes a dark ocean surface, which absorbs extraordinary warming of the Arctic region. off the coasts of Greenland and Labrador. Vegetation could re-appear due to higher have been banned. Yet strong interactions still stable noch stabil more solar radiation and thus amplifies the Recent observations suggest an accelerated A warming climate leads to an increased precipitation in the Sahel region, but this 13 Disruption of Marine Carbon Pump between stratospheric ozone depletion and warming. Over the last 30 years the area destabilization also due to melt-water lubri- freshwater flow into the ocean, thus decreas- greening of the Sahara may be overridden This “pump” acts as a sink for both natu- global warming may widen the ozone hole

covered by sea ice has decreased signifi- cation effects. The complete collapse of the ing the water’s density and slowing down by intensive land-use, especially grazing. ral and anthropogenic excess CO2. There over the Antarctic once again. Time Frame: cantly. This is also bad news for many spe- Greenland ice sheet would cause a global the deep water formation. Time Frame: If the re-greening happened, it could seal is a risk of a decline of this sink caused by ~ 10 –100 yr. cies, like seals or polar bears, which depend sea-level rise of 7 m. Time Frame: Unknown ~100 –500 yr. major sources of dust that is blown across increased ocean acidification and stratifica-

on that ice for hunting and breeding. Time due to highly non-linear processes. Current esti- the Atlantic and fertilizes South American tion owing to rising atmospheric CO2 lev- Frame: ~ 100 yr. mates: 300 – 1000 yr. ecosystems. Time Frame: ~ 50 yr. els. The acidification impedes floating and Emissions [GtC] 35 Projected carbon dioxide emissions from two 25 scenarios: business as usual (black line), 30 and climate protection100% policy in line with the Temperature Change (°C) 0,6 25 EU 2°C temperature target (grey line). The 80% 0,4 difference between these projectionsTemper atedepicts Grass Tropical Grass 20 the world’s mitigation challenge. 60% 0,2 15 Emissions Reduction 40 % 0 10 Summergreen Trees Raingreen 5 20 % Trees -0,2 Barren 0 0% -0,4 2000 2020 2040 2060 2080 2100 Years 1900 1950 2000 2050 2100 Years

1880 1900 1920 1940 1960 1980 2000 Years -10 -20 -30 -40 -50 -60 difference (mm)

Why Solving the Climate Problem Does Not Cost the Earth

The debate with the “climate sceptics” is However, many economists are worried that project, to be coordinated by Potsdam Insti- over – they were unable to produce any viable effective climate protection is unaffordable. tute scientists. The project – now known as Fishery Mana g em en t Athena, the goddess of wisdom and crafts- argumentsCouncil to counter the observationAuthority that In many models, the costs of ambitious emis- the Innovation Modelling Comparison Project manship, is usually portrayed as strong, the rise in atmospheric CO2 concentration is sions reduction have been estimated at levels (IMCP) – is well known in the scientific com- fair, and merciful. She was renowned for her mainly human-induced and that global warm- which suggest that it would be inadvisable, munity and among decision-makers in politics Scientific Fishing Firm superb logic and her well-considered, highly Institution ing is therefore primarilyGroup 1 an anthropogenic from an economic perspective, to limit the and business. Its findings have been presented ethical decisions. But she was also known effect. In future, the debateYield: will be dominated rise in globally averaged surface temperatures to Germany’s Chancellor, the IPCC, the oil Chan g e o f to be good in war tactics. On the frieze, she by Fishother Stock issues: how we can adapt to shifting to 2°C relative to the pre-industrial value. The company BP and the International Energy ˙ is seen near to her father, Zeus, killing one of climatic patterns and what must be done in resources which would be tied up in climate Agency, with all parties discussing the results Other Gaia’s sons. Species order to avoid dangerous climate change. protection – so the argument goes – would be with great interest. Fishing Firm The damage causedGroup 2 by climate change better invested in poverty reduction. However, The majority of models analysed in the Other Yield: canSpecies probably be limited to a manageable from a scientific perspective, a maximum of IMPC came to the remarkable conclusion that level if the rise in globally averaged surface 2°C is absolutely imperative to avoid danger- the costs of achieving the 2°C climate protec- temperatures does not increase to above 2°C ous climate change (see p. 21). Is a goal con- tion target amount to less than 1.0 per cent of

relative to the pre-industrial value. A politi- flict between economic growth and climate gross world product. The comparison showed Energy efficien c y cal consensus on a 2°C target will also facili- protection inevitable? Or could there be a that based on previous estimates, the costs of tate “burden-sharing” between adaptation strategy on which Athena, the goddess of sci- mitigation require a significant downward cor- R en e wable Energies

to climate change, on the one hand, and its ence, and Hermes, the god of economists and rection. However, this is only realistic if climate Carbon Capture & Storage mitigation, on the other. Even a successful thieves, might agree? policy actually implements appropriate solu- mitigation strategy will require adaptation to More and more researchers are now tions. The findings of the models indicate that the residual warming which will undoubtedly taking the view that the costs of climate pro- the following approaches are extremely signifi- 0 100 200 300 400 500 600 700 800 [GtC] take place. At present, however, there is little tection have been overestimated in most eco- cant in achieving the 2°C target. sign of a suitable adaptation strategy being nomic models as they do not take account of • Improving energy efficiency; put in place. It would therefore be quite irre- the innovations which could be initiated by a • Large-scale deployment of renewable sponsible to ease global climate protection well-designed mitigation policy. So in 2003, energy sources; targets and thus intensify the pressure on the the physicist Hans Joachim Schellnhuber and • Capture of the carbon produced by developing countries, in particular, to achieve a the economist Michael Grubb proposed the coal- and gas-fired power stations and high level of adaptation. establishment of a modelling comparison its storage in geological formations.

4000 2000

Longitu d e 0 -160 gradually increasing forcing -140 -120 -100 80 Latitu d e 70 -80 60 super-critical state -60 50 40 -40 30 sub-critical state -20 20 N

4000 4000 2000 2000

Longitude 0 Longitude 0 -160 -160 -140 -140 -120 -120 -100 80 Latitude -100 80 Latitude 70 70 -80 60 -80 60 -60 50 -60 50 40 40 -40 30 -40 30 -20 20 -20 20 Emissions [GtC] 35

1880 1900 1920 1940 1960 1980 2000 Years -10 -20 -30 -40 -50 -60 difference (mm)

Fishery Mana g em en t Council Authority

Scientific Fishing Firm Institution Group 1 Yield: Chan g e o f Fish Stock ˙

Other Species Fishing Firm Group 2 Other Yield: Species

26 CO2 reduction in gigatons of carbon [GtC], attributed to the options in the mitigation Energy efficien c y portfolio. Total reduction reflects the difference of business as usual and atmospheric stabiliza- tion at 450ppm CO from 2000 to 2100. R en e wable Energies 2

Carbon Capture & Storage

0 100 200 300 400 500 600 700 800 [GtC]

What role should nuclear energy play in the choose between two options: either economic context of climate protection policy? This is growth without mitigation, or mitigation with- Hermes, son of Zeus, had many meanings 4000 rightly a contentious issue: nuclear energy out growth. There can be harmony between during Antiquity. He was the god of dreams, 2000 could make a significant contribution – but not Athena and Hermes – but wisdom and recog- the protector of travellers and cattle, a guide Longitu d e 0 -160 until the second half of the century, and only nition of the limits to human action are also to Hades, and a messenger between gods. gradually increasing forcing -140 if technological development results in a plu- required in solving the climate problem. Just Cunning and quick, he was also the Greek god -120 tonium economy which extends the uranium as Odysseus had to lash himself to the mast of commerce, markets and thieves. -100 80 Latitu d e 70 supply and defuses the key problem of storage of his ship so as not to succumb to the sirens‘ -80 60 super-critical state of nuclear waste. An international congress song, so humankind must bind itself voluntar- -60 50 40 held at the Potsdam Institute in March 2006 ily to a long-term and credible climate policy -40 30 sub-critical state -20 20 N focussed on these issues. At present neither with the aim of coming as close as possible to the technological nor the political problems an emissions-free global economy by the end associated with a closed plutonium system of the 21st century. Furthermore, the develop- have been resolved. ing countries must be compensated for una- The extensive use of biomass in conjunc- voidable damage and their efforts to adapt to tion with carbon capture and storage is under “residual climate change” must be supported. discussion as a promising element of the miti- Humankind must commit to a credible long- gation portfolio, with the aim of drastically term climate policy in the coming decades. For cutting emissions and limiting atmospheric otherwise, it will be reminiscent of the heroes

CO2 concentration to a maximum of 450 ppm of Greek tragedies, whose desperate efforts to during the course of the 21st century. There are stop their entire world crashing down around still a number of unresolved issues here which them simply hastened their pitiful end. require thorough scientific analysis, such as the influence of extensive biomass use on the global hydrological cycle or the competition with food production. The Potsdam Institute’s research over 4000 4000 recent years shows that we do not have to 2000 2000

Longitude 0 Longitude 0 -160 -160 -140 -140 -120 -120 -100 80 Latitude -100 80 Latitude 70 70 -80 60 -80 60 -60 50 -60 50 40 40 -40 30 -40 30 -20 20 -20 20 Emissions Emission[GtC] 35s [GtC] 35

30 30 Temperature Change (°C) 0,6 100% 100% Temperature Change (°C) 0,6 25 25 80% 80% 0,4 0,4 TemperateTe Grmperass ate Grass Tropical GrTroasspical Grass 20 20 60% 60% 0,2 0,2 15 15 Emissions EmissionReductiosn Reduction 40 % 0 10 40 % 0 10 SummergrSumeen meTreesrgreen Trees Raingreen 20 % Raingreen 5 5 20 % Trees Trees -0,2 -0,2 Barren Barren 0 0 0% 0% -0,4 -0,4 2000 20002020 20202040 20402060 20602080 20802100 Year2100s Years 1900 1900 1950 1950 2000 2000 2050 2050 2100 Year2100s Years

1880 19001880 19201900 19401920 19601940 19801960 20001980 Ye2000ars Years -10 -20 -10-30 -20-40 -30-50 -40-60 -50differ-60encediffer (mm)ence (mm)

Avoiding overexploitation of marine resources 29 is of vital interest for global food security. Fishery Fishery Mana g em eMann t a g em en t Council Council Authority Authority Integrated modelling is one prerequisite to anticipate critical developments and allows to develop sustainable management regimes Scientific Scientific Fishing FirmFishing Firm in a complex interplay of different interests. InstitutionInstitution Group 1 Group 1 Shown here is just the basic dynamic of Yield: Yield: the system. Chan g e o f Chan g e o f Fish StockFish Stock ˙ ˙

Other Other Species Species Fishing FirmFishing Firm Group 2 Group 2 Other Other Yield: Yield: Species Species

Sustainability Research Energy efficieEnerngy c y efficien c y

R en e wableR eEnn eer wgiesable Energies If we are to achieve a sustainable civilization ing to restore its balance, and reacts more of Rome – finally complete. Research can and which allows humankind to live in dignity and strongly the more its biogeochemical balance must offer its services to a process which paci- Carbon CapturCarbone & CapturStoragee & Storage peace, cooperation between social and natural is disturbed. How can we avoid a fatal clash fies the now precarious relationship between scientists is essential. between civilization and the Earth System, humankind and nature. 0 100 0200100300200400300500400600500700600800700[GtC]800 [GtC] This is readily explained. Whereas in Greek leaving room for adaptation to a natural envi- The Potsdam Institute is therefore tak- antiquity, it was the moral order and the con- ronment in transition? ing a further step forward in 2007: it is adding sensus between city-states which were impor- So the question is not only how to deal transdisciplinary research to its field of activi- tant, while the desire for control over nature with the impacts of climate change, but also ties alongside its single-discipline research was axiomatic, we now face a global and far – and above all – how to slam shut the lid of domains and interdisciplinary collaboration. more complex threat to peace: humankind has Pandora’s box as quickly as possible. And that It is doing so in the recognition that an under- intervened so dramatically in natural cycles requires joint action by a world community standing of global problems must include an that we are increasingly being confronted with which is currently organized, first and fore- awareness of sustainable solutions. the consequences of an environmental system most, through its markets. What is required The time has come for Eirene and Athena in disarray. is a new definition of the relationship between to depart from their Olympian homeland and 4000 4000 It is understandable if people regard humankind and nature which is no longer embark on a journey across the globe, bring- 2000 2000 nature as the “natural enemy” in the truest driven by utilitarian interests. This requires ing their vital wisdom, knowledge and peace- Longitu d eLon0 gitu d e 0 Eirene was the goddess of peace and of sense of the word – it is dangerous to underes- both a catalogue of measures and a timeta- ability to the megacities, farmlands, primeval-160 -160 gradually grinacrduallyeasing in focrrcineasing g forcing the seasons, especially spring, when peace in timate it. And humankind has underestimated ble: how can we decarbonize industrial society forests and steppes in order to create sustain- -140 -140 Greece was most at risk. The marble statue nature, especially its response to newly devel- within a matter of decades without heighten- able environments for the future. -120 -120 80 Latitu d e -100 -100 80 Latitu d e shows Eirene holding the infant Ploutos (wealth) oped synthetic compounds and the impacts of ing the conflicts between rich and poor and 70 70 -80 -80 60 60 in her arms. super-criticalgeneratingsuper-critical state energy state from fossil fuels. The Earth deepening geostrategic imbalances? Here, we 50 -60 -60 50 40 System, as sophisticated and finely tuned as the must look to science, for it can provide “inte- -40 40 -40 30 30 sub-criticalsub-critical state state human hormone system, clearly reacts badly if grated” strategies for this purpose. -20 20-20 20 N N its chemistry is disrupted. What humankind From the outset, the Potsdam Institute currently regards as unusual changes or even has aimed to bridge the gap between the social an assault by natural forces is no more than and the natural sciences. But only now, after the response of an environment which – in line 15 years, is the paradigm shift – whose first with the laws of natural science – is attempt- tentative steps were set in train by the Club

4000 4000 4000 4000 2000 2000 2000 2000

LongitudeLongitude0 0 LongitudeLongitude0 0 -160 -160 -160 -160 -140 -140 -140 -140 -120 -120 -120 -120 80 Latitude 80 Latitude -100 -100 80 Latitude -100 -100 80 Latitude 70 70 70 70 -80 -80 -80 60 60 -80 60 60 50 50 -60 -60 50 -60 -60 50 40 40 -40 40 -40 40 -40 30 30 -40 30 30 -20 20-20 20 -20 20-20 20 30

Selected References p. 7 Schneider von Deimling, T., Held, H., p. 18 Schellnhuber, H. J. et al. (eds.) (2006): Rahmstorf, S. & Schellnhuber, H. J. Ganopolski, A. & Rahmstorf, S. (2006): Mikusky, E., Owinoh, A. & Klein, R. (2005): Avoiding Dangerous Climate Change. (2006): Der Klimawandel. Diagnose, Climate sensitivity estimated from ensemble On the influence of diabetic effects on the Cambridge, UK: University Press. Prognose, Therapie. München: Beck. simulations of glacial climate. motion of 3D-mesoscale vortices within Climate Dynamics, 27, 149–163. a baroclinic shear flow. In: Computational p. 29 p. 11 Fluid and Solid Mechanics. Elsevier. Kates, R. W. et al. (including Jaeger, C. C. & Werner, P. C., Gerstengarbe, F.-W., p. 15 Schellnhuber, H. J.) (2001): Fraedrich, K. & Oesterle, H. (2000): Alcamo, J., van Vuuren, D., Ringler, C., Schubert, R., Schellnhuber, H. J., Sustainability Science. Science 292, Recent climate change in the North Atlantic/ Cramer, W., Masui, T., Buchmann, N., Epiney, A., 64 1–642. European sector. International Journal of Alder, J. & Schulze, K.(2005): Griesshammer, R., Kulessa, M., Climatology, 20, 463 – 471. Changes in Nature’s Balance Sheet: Model- Messner, D., Rahmstorf, S. & Jaeger, C. C. (2004): based Estimates of Future Worldwide Ecosys- Schmid, J. (2006): Climate Change: Combining Mitigation and Rahmstorf, S. (2007): tem Services. Ecology and Society 10(2), 19. Die Zukunft der Meere – zu warm, Adaptation. In: Michel, D. (ed.), Climate Policy A Semi-Empirical Approach to Projecting www.ecologyandsociety.org/vol10/iss2/art19/. zu hoch, zu sauer. WBGU, Berlin. for the 21st Century, pp. 375–396. Baltimore, Future Sea-Level Rise. Science, 315, 368–370. USA: Johns Hopkins University Press. Schröter, D., Cramer, W., Leemans, R., p. 21 Rahmstorf, S., Cazenave, A., Church, J. A., Prentice, I. C. et al. (2005): Schellnhuber, H. J. & Held, H. (2002): Schellnhuber, H. J., Crutzen, P. J., Hansen, J. E., Keeling, R. F., Parker, D. E. & Ecosystem Service Supply and Vulnerability How Fragile is the Earth System? Clark, W. C., Claussen, M. & Somerville, R. C. J. (2007): to Global Change in Europe. Science, 310, In: Briden, J. & Downing, T. (eds.), Managing Held, H. (eds.) (2004): Recent Climate Observations Compared to 1333–1337. the Earth: The Eleventh Linacre Lectures, 5–34, Earth System Analysis for Sustainability. Projections. Science (Express), 1 February 2007. Oxford: University Press. Boston: MIT Press. p. 17 p. 12 Werner, P. C. & Gerstengarbe, F.-W. (1997): Held, H. & Kleinen, T. (2004): Haas, A. & Jaeger, C. C. (2005): Ganopolski, A., Rahmstorf, S., A proposal for the development of climate Detection of climate system bifurcations Agents, Bayes, and Climatic Risks – A Modular Petoukhov, V. & Claussen, M. (1998): scenarios. Climate Research, 8 (3), 171–182. by degenerate fingerprinting. Geophysical Modelling Approach. Advances in Geosciences, Simulation of modern and glacial climates Research Letters, 31, L23207. 4, 3–7. with a coupled global model of intermediate Gerstengarbe, F.-W. & Werner, P. C. (2005): complexity. Nature, 391, 351–356. Simulationsergebnisse des regionalen Klima- p. 25 modells STAR. In: Wechsung, F., Becker, A., Edenhofer, O., Carraro, C., Hare, B. & Meinshausen, M. (2006): Gräfe, P. (eds.), Auswirkungen des globalen Koehler, J. & Grubb, M. (2006): How Much Warming are We Committed Wandels auf Wasser, Umwelt und Gesellschaft Endogenous Technological Change and to and How Much can be Avoided? im Elbe-Gebiet. Berlin, 110–118. Weißensee- the Economics of Atmospheric Stabilisation. Climatic Change, 75, 111–149. Verlag. The Energy Journal, 27, Special Issue.