Energy and Us

1. Energy and Us • We live in a very energy intensive world • Almost all aspects of our lives involve the use of energy • We use more energy each year • Everyone else’s energy use is growing faster than ours • We are profligate in our use.

4. Energy use by source

7. Energy supply vs. energy demand American (and world) economy grows, almost every year. Energy consumption grows, too. Fossil fuels come out of the ground. There is a finite amount of them. Why should we expect supply of energy to grow with the demand for it? Might a shortage of energy cause disruption in economic progress?

8. What good is the Law of Conservation of Energy? Energy is conserved (i.e. transformed at well defined “exchange rates”.) 1st Law of Thermodynamics. Energy cannot come from nothing (i.e. free) YOU CAN’T WIN

9. What good is the Law of Conservation of Energy? Transformations of energy inevitably leads to degradation from useful forms to useless room temperature thermal energy. 2nd Law of Thermodynamics describes this degradation. YOU CAN’T EVEN BREAK EVEN We’re stuck in a world where we constantly need to replenish high quality energy.

11. Finite resources vs. human progress Thomas Malthus (1798): An Essay on the Principle of Population “The power of population is indefinitely greater than the power of the earth to produce subsistence for man.” Concern about growth outstripping finite resources has been a continued concern. World population growth in mid-20th century sparked concern about famine, overcrowding, and pollution. The "Energy Crisis"

12. Arguments against limits to petroleum supplies Some argue that we will evade running up against limits into the indefinite future, because of • the likelihood of new discoveries of resources, • improved efficiency in extracting petroleum, • new technology to make “unconventional oil” supplies extractable at reasonable cost. Or, perhaps none of this will matter, because we’ll replace our need for oil “just in time.”

13. Arguments that we are about to run out of cheap oil New discoveries have been few over the past twenty years. For known oil fields, we have extracted close to half of the total petroleum contents. New technologies have not yet come along to make unconventional resources usable at reasonable prices. The "Energy Crisis"

14. Why this matters The U.S. is the largest consumer of petroleum, and of energy in general. Our prosperity and security is built on our energy consumption. We can change, but not without cost. Expect continued economic dislocation throughout your adult lives. The "Energy Crisis"

16. Oil production

17. Challenges facing your generation • Where will we get our energy? • Maybe we can learn to live with less energy use. • We are changing our environment. • Climate Change (global warming)

18. Understanding Global Warming • The Intergovernmental Panel on Climate Change (IPCC) declared that evidence for global warming is unequivocal and that it is “very likely” due to human-induced changes in greenhouse gases. • Climate change has occurred throughout Earth’s history. What is unusual is the extremely rapidrateat which temperatures are changing now.

19. Global Warming • Two factors are responsible for the human impacts on ecosystems: • The rapid increase in human population. • The rapid increase in human resource use. • Residents of industrialized countries, though relatively few in number, burn extraordinary quantities of fossil fuels and thus are largely responsible for global warming.

20. Understanding the Problem • The chain of causation begins with the direct link between the CO2 released by human fossil fuel use and increases in atmospheric CO2. • It continues with a link between high atmospheric CO2 and increased trapping of infrared radiation • it concludes with recent and dramatic increases in average temperatures around the globe.

29. Understanding the Problem • Although the temperature increases being observed are global averages, there is a lot of temporal and spatial variation. • However, averaged over the entire planet and over time, Earth is already much warmer than it was just a few decades ago, and is projected to get much more so. • The amount of this rise depends in part on whether CO2 and other greenhouse gases continue to increase. To date, however, there is no indication that the rate of increase is slowing.

30. The Earth is Warming • Global warming is a fact. • There is no dispute about this amongst scientists. • If this continues can have devasting effects • Is this being caused by human activity?

32. Can we Believe “Models” • The basic story (Greenhouse effect) is solid science. Eventually it must cause warming • Sophisticated computer models • Predict more than one number or trend, Many complicated, interactive phenomena e.g. • Relative change in T in oceans and land • Rates of change in T in tropics and arctic • Which areas have more, less rain

33. Positive and Negative Feedback • Positive feedback occurs when changes due to global warming result in a release of additional greenhouse gases, accelerating the warming trend. • A warmer and drier climate has increased the frequency of forest fires, which release CO2, leading to more warming. • Traditionally, tundras sequester carbon in the form of soil organic matter. However, greenhouse gases that are trapped in permafrost could be released when tundras warm.

34. Positive and Negative Feedback • Negative feedback occurs when changes due to global warming result in increased uptake and sequestration of CO2 and other greenhouse gases—meaning that global warming should be reduced. • Growth rates of several tree species and some agricultural crops increase in direct response to increasing atmospheric CO2. Because CO2 is required for photosynthesis, it can act as a fertilizer.

35. Global Warming • The models currently being used suggest that average global temperature will undergo additional increases from approximately 1.1ºC to 6.4ºC (2.0ºF–11.5ºF) by the year 2100. • The low number is based on models that assume no further increase in greenhouse gases over present levels; the high number is based on models that assume continued intensive use of fossil fuels and increases in greenhouse gases.

36. Your Challenge