Easter Island: Lessons from Environmental Degradation

1. CHAPTER 1 Science and the Environment

2. An introduction to environmental science • On Easter Sunday, 1722, Dutch sailors named a remote South Pacific island Easter Island • It is the most remote spot on the planet • Inhabited by Polynesians who were living primitively • The sailors found large stone statues on the island • Evidence of a sophisticated civilization • The past culture and civilization had vanished

3. Easter Island once had a prosperous culture

4. Easter Island: the past • Polynesians arrived on the island around 1200 A.D. • It’s an environmentally fragile island • Small, isolated, dry, cold, nutrient-poor • At first, it was abundantly forested • Palms, conifers, and sandalwood • The inhabitants cut trees to • Clear land for agriculture • Provide structural materials • Move the stone heads from the quarries to the sites at which they would be erected

5. Easter Island: an environmental catastrophe • By 1650, all the trees were gone • The soil washed into the sea • The eroded soil baked, decreasing agriculture • Degraded soil, depleted forest and water resources • Existence became harder • Workers revolted against the ruling religious elites • Workers fought among themselves • Starvation and disease became epidemic • Without trees, no one could leave the island by boat • The population was down to a few thousand by 1722

6. Easter Island: consequences of degradation • Easter Islanders (Rapa Nui) did not anticipate the consequences of their actions • They suffered terribly from their contacts with the “civilized” world • Visiting whalers infected them with venereal diseases • Peruvian slavers captured them for the slave trade • Smallpox killed many people • By 1877 only 111 Rapa Nui remained • After annexation by Chile, the government enclosed the Rapa Nui in one village

7. Easter Island: conditions have improved • In the mid–20th century, archaeologists brought attention to the island • Stone statues have been restored • The Rapa Nui regained some control over their destiny • Tourism has developed • But they still depend on imported food • Unemployment and alcoholism are serious problems

8. Hanga Roa harbor on Easter Island

9. Lessons from Easter Island • When the following occur: • A society does not care for its environment • Its population increases beyond the capacity of the land and water to provide food for all • The disparity between haves and have-nots widens • Then, its civilization collapses • Other civilizations collapsed when they failed to recognize the constraints of their environment • Mayans, Greeks, Incas, and Romans • The future is uncertain for Easter Island • Much depends on the efforts of the Rapa Nui

10. The state of the planet • The world faces four unhealthy global trends (1) Increasing population growth and its detrimental effects on human well-being (2) A decline of vital ecosystem services (3) The negative impacts of global climate change (4) A loss of biodiversity

11. Increasing populations decrease human well-being • Today, there are more than 6.8 billion persons • The population grew by 2 billion in the last 25 years • 75 million persons are added each year • By 2050, there could be 9.1 billion people • They will have to be fed, clothed, housed, and have jobs • Most population increases will be in developing countries • 985 million experience extreme poverty ($1 a day) • Over 800 million are malnourished • 6 million preschoolers die each year of hunger and malnutrition

12. The world’s population has exploded

13. The Millennium Development Goals (MDGs) • In 2000, all United Nation member countries adopted the Millennium Development Goals • To reduce extreme poverty and its effects on human well-being • If these goals were met by 2015, 400 million people would be lifted out of extreme poverty • Progress has been made • Measles deaths in Africa have been reduced by 91% • AIDS deaths have declined • The lack of family planning hinders reaching MDGs

14. Global economic production • Has doubled since 1986 • Average gross domestic product (GDP) in low-income countries has improved • But real income in most developing countries is falling • Because of the large inequalities in wealth between them and developed countries • Stabilizing population growth in developing countries is also essential for closing this economic gap

15. The decline of ecosystems • Ecosystems support human life and economies with goods and services • These vital resources are not being managed well • Humans are depleting groundwater, degrading soils, overfishing, and depleting forests • The world economy depends on renewable resources • For fresh water, food, fuel, wood, leather, furs, etc. • For raw materials for fabrics, oils and alcohols, etc. • Agriculture, forestry, and fishing are responsible for 50% of all jobs worldwide

16. Ecosystems provide services • They support human life and economic well-being • Waste breakdown, climate regulation, erosion control, pest management, maintenance of nutrient cycles • These goods and services are “ecosystem capital” • Human well-being and economic development depend on the products of this capital—its income • Goods and services are provided as long as the ecosystems producing them are protected • Ecosystem capital in a nation and its income-generating capacity represent a major form of a nation’s wealth

17. The Millennium Ecosystem Assessment • Restoring Nature’s Capital: An Action Agenda to Sustain Ecosystem Services (2007) • Focused on services ecosystems provide to humans • Produced an agenda for ecosystem restoration • The Millennium Ecosystem Assessment • Gathered information on the world’s ecosystems • Involved 1,360 scientists from 95 countries • Gathered, analyzed, and synthesized information • Focused on links between ecosystem goods/services and human well-being

18. Findings of the Millennium Ecosystem Assessment • Humans have altered the world’s ecosystems more rapidly and profoundly over the past 50 years than at any time in human history • Over 60% of ecosystem goods and services are being degraded or used unsustainably • If this is not reversed, there will soon be deadly consequences • This project builds a knowledge base for sound policy decisions and management • Policy makers and managers must act on that knowledge

19. Global climate change: a serious problem • Global climate change is a current serious problem • Due to the accumulation of greenhouse gases • Carbon dioxide is a by-product of burning fossil fuels • Carbon dioxide is a natural component of the atmosphere • It is required by plants for photosynthesis • It’s important to the Earth’s atmosphere energy system • The greenhouse effect: carbon dioxide absorbs infrared (heat) energy radiated from Earth’s surface, which warms the lower atmosphere

20. Global temperature and carbon dioxide

21. Intergovernmental Panel on Climate Change (IPCC) • Established by the United Nations in 1988 • It reports its assessment of climate change every 5 years • The Fourth Assessment Report (FAR) (2007) • Input from thousands of scientific experts and hundreds of authors • This assessment produced convincing evidence that human-induced climate change is already severely impacting global climate and sea level • Concluded that future changes could be catastrophic if emissions of greenhouse gases are not controlled

22. The Kyoto Protocol: reducing greenhouse gas emissions • 166 nations met in Kyoto, Japan, in December 1997 • Most industrialized nations agreed to reduce emissions • Ratified in 2005, it is in force in most industrialized nations • The United States, the biggest emitter, withdrew in 2001 • Kyoto is only a first step • Levels of greenhouse gases will continue to rise • Short-term economic impacts conflict with the long-term consequences of climate change • Climate change is one of the defining environmental issues of the 21st century

23. Loss of biodiversity • Biodiversity: variability among living organisms and the ecological complexes of which they are part • Causes of biodiversity losses • Conversion of land • Pollution • Exploitation for commercial value • Species are hunted, killed, and marketed illegally • Species are declining in their range and/or population size • Of 5–30 million species, 2 million have been described • Vertebrate species have declined by 27% since 1970

24. Natural ecosystems give way to development

25. Biodiversity loss is crucial • We threaten our well-being when we diminish biodiversity • It is the mainstay of agricultural crops and medicines • Losses will curtail development in these areas • It helps maintain natural systems • Enabling them to recover after a disturbance • It provides essential goods and services • Particularly for the poor • Aesthetic and moral arguments for biodiversity • Do we have a moral responsibility to protect and preserve the amazing diversity of life on Earth?

26. Environmental science • Human societies live in the natural world • We use materials, converting parts of it into the built environment (towns, factories, highways) • We change natural ecosystems into agricultural ones • We use the environment to dump wastes • The environment: is an inclusive concept • It includes the natural world • Human societies and the human-built world

27. Human successes and failures • Humans have achieved great successes • Domesticated landscapes to produce food for billions • Converted natural materials into goods and services • Tapped carbon-based fuels for electricity, heat, power, manufacturing • Success carries dangers, too • Air pollution and increased atmospheric temperature • Environmental contamination • Overharvested forests and fisheries

28. Environmental science • Environmental science: the study of how the world works • Examines cause-and-effect relationships underlying issues and problems that rise from our use of the natural world • It provides answers that allow societies to make changes consistent with a sustainable future • Encompasses many disciplines • History, engineering, geology, physics, medicine, biology, sociology • It is the most multidisciplinary of all sciences

29. The early environmental movement • Has its roots in the late 19th century • Unique, wild aspects of the U.S. were disappearing • In 1890, the frontier was closed • No part of the country was totally uninhabited • Conservation groups were formed • National Audubon Society, National Wildlife Federation, Sierra Club • President Theodore Roosevelt placed 230 million acres under public protection • A national environmental consciousness was stirring

30. Farming and drought produced the Dust Bowl

31. The Great Depression and World War II • During the Great Depression, conservation provided environmental protection and jobs • The Civilian Conservation Corps (CCC) built trails, planted trees, and improved national parks and forests • The years after World War II brought technological optimism • Tremendous production capacity and new technology were redirected to peacetime applications • Environmental problems became obvious • Polluted air, fouled rivers and beaches, species declines

32. The modern environmental movement • Rachel Carson wrote Silent Spring (1962) • She described a future with no songbirds, along with other consequences of pesticide pollution • The modern environmental movement: a newly militant citizenry demanded • Curtailment of pollution • Cleanup of polluted areas • Protection of pristine areas • It began as a grassroots initiative • Continues to command public interest and support

33. Environmentalism • Wildlife advocates became active in the environmental movement • Environmental Defense Fund, Natural Resources Defense Council, Greenpeace, Union of Concerned Scientists • Environmentalists: persons and organizations with a strong focus on environmental concerns • Environmentalism: the widespread development of the environmental movement

34. The environmental movement has been successful • Congress created the Environmental Protection Agency (EPA) in 1970 • Congress passed laws for pollution control and wildlife protection • Society has spent billions of dollars in pollution control • Governments have spent billions upgrading sewage treatment and on refuse disposal • The air and water are much cleaner than in the 1960s • Without the environmental movement, our air and water would be a toxic brew

35. Environmentalism has critics • Early in the environmental movement • It was easy to identify specific sources of problems • Solutions seemed straightforward • But polluting industries demanded deregulation • They believed regulations harmed the economy • They found allies in Congress and some presidents • Political battles surround almost every environmental issue • Bitter conflicts arise over publicly owned resources • Special interests oppose regulations • Politics always accompanies policy

36. Moving toward sustainability • To move toward sustainability we need: • Sound science: understanding how the world works and how humans interact with it • Sustainability: the goal we should be working toward • Stewardship: managing natural resources and human well-being for the common good

37. Three unifying themes for sustainability

38. Sound science: the scientific method • Many environmental issues are so controversial, people are left confused • The scientific method: a way of gaining knowledge • Science: all the knowledge gained through this method • Is legitimate, in contrast with junk science: information that is presented as science but is not • Junk science does not conform to the rigorous methods and practices of legitimate science • Sound science involves using the scientific method to understand how the natural world works

39. Four assumptions of the scientific method • What we perceive with our senses represents objective reality • Objective reality functions according to certain basic, consistent principles and natural laws • Every result has a cause • Every event in turn will cause other events • Events do not occur without reason • Through observation, manipulation, and reason, we can discover and understand natural laws by which the universe functions

40. The scientific method: observations • The scientific method consists of observation, hypothesis, test (experiment), explanation • Observation: seeing, hearing, smelling, etc. • Can lead to explanations of some natural phenomena • The basis for natural history, astronomy, anthropology, evolutionary biology • Is involved in zoology, botany, geology, comparative anatomy, and taxonomy • Careful observation is the keystone of science • Helps model how the world works

41. The scientific method

42. Not every observation is accurate • This can be due to honest misperceptions or even calculated mischief • Be skeptical of any new report until it is confirmed • This involves further investigation • As observations are confirmed, they gain the status of factual data • Facts: things or events that have been confirmed by more than one observer • Remain open to being reconfirmed • Things that cannot be confirmed (e.g., UFOs) belong in the realm of speculation

43. Experimentation • Sets up situations to make systematic observations regarding causes and effects • For example, the atomic theory is a cause-and-effect picture that measured how chemicals react • Similarly, by putting plants and animals into specific situations, responses can be observed and measured • Is limited to things that can be manipulated • Not good for things that happened in the past

44. An experiment shows the importance of mycorrhizae

45. Experimentation is usually systematic • Careful accounts are usually kept to have an accurate record of causes and effects • For example, to discover why Indian vultures declined: • Hypotheses (educated guesses) were made about the cause of the decline • Each hypothesis was tested through observation or experimentation • Experimental results showed that a veterinary drug used in livestock killed vultures when they ate carcasses

46. Testing a hypothesis: an example Animation: Spontaneous Cell Generation Hypothesis - Part 1

47. Testing a hypothesis: an example Animation: Spontaneous Cell Generation Hypothesis - Part 2

48. Testing a hypothesis: an example Animation: Spontaneous Cell Generation Hypothesis - Part 3

49. Theories • Hypotheses tentatively explain how observations are related • A hypothesis becomes a theory only after much testing and confirmation • A theory is logically consistent with all observations • Theories can suggest or predict certain events • Predictions require more experiments, observations, etc. • A theory represents a valid interpretation of reality • When it provides a logically consistent framework for all relevant observations (facts) • When it can be used to reliably predict outcomes

50. Is one theory as good as another? • Some people argue that a theory is not proven fact • So all theories are equal • But one theory may have overwhelming supporting evidence that contradicts other theories • To evaluate a theory • Ask about its supporting evidence • Does another theory have more or less evidence?