Frank Press Raymond Siever John Grotzinger Thomas H

Frank Press • Raymond Siever • John Grotzinger • Thomas H. Jordan Compreendendo a Terra 4 a Edição Cap. 23: Ambiente, Mudanças Globais, e Impactos Humanos Lecture Slides prepared by Bill Dupré • Peter Copeland Copyright © 2004 by W. H. Freeman & Company

Interacting Geosystems: Climate – Plate Tectonics – Geodynamo Fig. 23. 1

O Simulador da Terra: maior computador já construído Centro de ciências da Terra, Yokohama-Japão Fig. 23. 2

Fig. 23. 2

Fig. 23. 2

Componentes do Sistema Climático da Terra Fig. 23. 3

As atividades antrópicas podem resultar em mudanças: Atmospheric composition and circulation Sea ice and extent of glaciers The hydrologic cycle Land surface, vegetation, and ecosystems Fig. 23. 3 Oceanic circulation, sea level, and geochemistry

O gelo marinho é parte importante da Criosphere Arctic Sea ice flowing south through the Bering Strait, May 2002 Fig. 23. 4

Energia Geotérmica ~ 0. 06 Watts/meter 2 Energia solar ~ 342 Watts/meter 2 O calor radiante da Terra deve ser equivalente ao gerado pelo sol Fig. 23. 5

Entrada e Saída de radiação na Atmosfera Terrestre Fig. 23. 6

Quais são os gases do efeito estufa? (What are the greenhouse gases? ) (excluindo H 2 O) • Dióxido de Carbono: 49% • Metano: 18% • “CFC’s”: 14% • Óxidos Nitrosos: 06% • Outros: 13%

Qual a fonte do CO 2 adicionado? • Queima de comb fóssil: 75% • Desmatamento: 15% • Manufacturing: 07% • Combustível de madeira: 03%

Global Temperatures Compared to Increased CO 2 Concentration Fig. 23. 8 a

Global Temperatures and CO 2 Concentrations Over the Last Millennium Fig. 23. 8 b

But…. How can we determine temperature and CO 2 content prior to instrumental readings? Fig. 23. 8 b

The ice core, such as at Vostok Science Station in Antarctica provides over 100, 000 years of data on: 1) temperature, 2) CO 2 content, and 3) methane content Box 16. 1

Temperature and greenhouse gas concentrations both decline during glacial periods Fig. 23. 7

Temperature and greenhouse gas concentrations both rise rapidly during deglaciation Fig. 23. 7

Climate has been relatively warm and stable during the last 10, 000 yrs, the Holocene interglacial period Fig. 23. 7

El Nino and La Nina Box 23. 1

During normal years, warm surface waters in the Pacific lie in the east off Indonesia Box 23. 1

During normal years, warm surface waters in the Pacific lie in the east off Indonesia When the pattern oscillates to an “El Nino”, the warm water shifts east Box 23. 1

During normal years, warm surface waters in the Pacific lie in the east off Indonesia When the pattern oscillates to an “El Nino”, the warm water shifts east “La Nina” is characterized by colder sea-surface temperatures and stronger trade winds in the eastern tropical Pacific Box 23. 1

During “Normal Years” Warm water in the western Pacific causes low pressure and high rainfall; pressure system drives tradewinds from east to west; tradewinds drive warm water to the west; causing cold water to rise off South America and flow west. South America Box 23. 1

During “El Nino” Warm water shift to the eastern Pacific causes drought in western Pacific; low pressure over the warm eastern Pacific causes heavy rains and inhibits upwellings along the coast of South America Box 23. 1

Transport Processes Between Components of the Climate System Fig. 23. 9

The Calcium Cycle (showing fluxes in and out of the ocean) Fig. 23. 10

The Carbon Cycle (showing global reservoirs and fluxes) Fig. 23. 11

Human Effects on the Carbon Cycle Fig. 23. 12

Human Effects on the Carbon Cycle Human activities release ~7. 1 Gt* of carbon into the atmosphere each year *Gt = gigaton Fig. 23. 12

Human effects on the Carbon Cycle Human activities release ~7. 1 Gt* of carbon into the atmosphere each year *Gt = gigaton New plant growth and air-sea exchange removes ~3. 8 Gt/yr Fig. 23. 12

Human effects on the Carbon Cycle Human activities release ~7. 1 Gt* of carbon into the atmosphere each year *Gt = gigaton New plant growth and …yielding a net Air-sea exchange atmospheric increase removes ~3. 8 Gt/yr of ~ 3. 3 Gt/yr. Fig. 23. 12

Fig. 23. 13

Fig. 23. 13

Before and After the Effects of Acid Rain Fig. 23. 13

Acidity of Rain: 1955 -1998 Fig. 23. 14

Burning high-sulfur coal generates atmospheric sulfuric acid which falls as acid rain down-wind, to the northeast. Fig. 23. 14

Rains became more acidic and affected broader areas until sulfur-reducing regulations were enacted… Fig. 23. 14

…reducing acid rain in the Northeast, however coal-fired power plants in the Southwest have increased acid rain there. Fig. 23. 14

Fig. 23. 15

Projected Changes in Ozone Concentration With and Without the Montreal Protocol Fig. 23. 16

Projected Changes in CO 2 Concentration Under Three Different Scenarios Fig. 23. 17 a

Projected Changes in Global Temperature Under Three Different Scenarios Continued reliance on fossil fuels increased reliance on nonfossil fuels Range of uncertainty Rapid conversion to cleaner and more resource-efficient technologies Fig. 23. 17 b

Global warming is projected to reduce the north polar ice cap, disrupting Arctic ecosystems, but possibly improving navigation. Fig. 23. 18

Potential Climate-Change Effects on Various Systems Potential Effects Table 23. 1

Potential Climate-Change Effects on Various Systems Potential Effects Table 23. 1

Table 23. 1