UCLA Environment 10 Chapter 1

Know the world's present population, to the nearest billion. Explain how population growth rates over the last few centuries compare with those of earlier times, and why. Describe how global growth rates have changed over the last half-century.

(8 billion as of 2020) Population growth rates grew relatively slowly until the 19th century, when they rose sharply due to an expansion of habitat- we had the technology to make settlements anywhere. The last-half century has brought massive increase in growth rates.

Why is the environment difficult to study?

- Nature is complicated - Scale is often enormous - Difficult or impossible to conduct controlled experiments - Includes many ways of knowing - Benefits from cultural diversity

Why do environmental problems exist?

- rate of resource consumption - human population size

Describe the kinds of information that are used to determine the internal composition of the earth.

1. We can look at the starting composition from which the solar system formed. 2. We can make inferences by analyzing meteorites believed to have formed at the same time. 3. Geophysical data shows that the earth is zoned and can show the densities of the layers.

hypothesis

A conceptual model or explanation for a set of data, measurements, or observations

theory

A generally accepted explanation for a set of data or observations; its validity has usually been tested by the scientific method

Indicate what regions of the world currently have the fastest and slowest rates of population growth.

Africa has the fastest rate of population growth as a whole, and Europe has the slowest population growth.

Explain the concept of doubling time and how population doubling time has generally been changing through history. Know the approximate doubling time of the world's population at present.

Doubling time is the length of time required for a population to double in size (Doubling time = 10/growth rate). It's been decreasing quickly in recent decades, and the current doubling time is about 70 years.

Explain the differences among facts, scientific hypotheses, and scientific theories.

Facts - an observation that has been confirmed repeatedly and is accepted as true (although its truth is never final) Scientific hypotheses - A conceptual model or explanation for a set of data, measurements, or observations Scientific theories - A generally accepted explanation for a set of data or observations; its validity has usually been tested by the scientific method

exponential growth

Growth characterized by a constant percentage increase per unit time

If earth's population has already exceeded the planet's carrying capacity, explain the implications for achieving a comfortable standard of living worldwide.

If we've already passed carrying capacity, then we cannot achieve a comfortable standard of living worldwide because of lack of resources, at least until the population drops.

Many earth materials are transformed through processes that are cyclical in nature. Describe one example.

Lava -> Rock -> Erosion -> Solidification -> Movement -> Melting

scientific method

Means of discovering scientific principles by formulating hypotheses, making predictions from them, and testing the predictions

Describe the process by which the solar system is believed to have formed, and explain why it led to planets of different composition, even though the planets formed simultaneously.

Our solar system is believed to have formed from a rotating cloud of gas and dust, with some of the mass coalescing into the sun and the rest condensing to form planets. Their composition depended largely on how close they were to the sun, so planets close to the sun are generally made of metallic iron and minerals with high melting temperatures.

What are TEK/IK projects and how are they relevant today?

TEK/IK means "traditional ecological knowledge and indigenous knowledge", such as Inuit observations of climate change study. Today known as "indigenous knowledge"/"traditional knowledge", it's widely recognized in fields like agroforestry.

Describe any one of the older theories of lunar origin, and note at least one fact about the moon that it fails to explain.

The "sister-planet model" suggests the Earth and moon accreted close together during solar system formation and that's why the moon orbits Earth. However, it doesn't explain the chemical differences between the moon and Earth.

carrying capacity

The ability of a system (or the whole earth) to sustain its population in reasonably healthy and comfortable conditions

Outline the processes by which the earth's atmosphere and oceans formed, and how the atmosphere has changed over earth's history.

The hydrologic cycle includes the processes of evaporation, precipitation, movement of water on the surface. The rock cycle includes formation out of lava, physical and chemical weathering, solidification of debris, movement from plate tectonics, and melting. There is also cycling of chemicals and materials such as CO2. The atmosphere began full of nitrogen and CO2, but with photosynthesis, the CO2 has been largely replaced by oxygen.

core

The innermost zone of the earth; composed largely of iron

doubling time

The length of time required for a population to double in size (Doubling time = 10/growth rate)

Explain how the newly formed earth differed from the earth we know today.

The newly formed earth lacked modern oceans and atmosphere, and most likely had a barren surface. Over time, the heat from dust and meteors colliding, caused denser materials to sink to the inside of the early, which is why modern earth has the core, mantle, and crust.

crust

The outermost compositional zone of the earth; composed predominantly of relatively low-density silicate minerals

Compare the age of Earth with the length of time humans have inhabited the planet and come to influence their geologic environment.

The planet is approximately 4 billion years, while humans have only been here for only half a million years. (6 secs out of a day)

environmental geology

The study of the interactions between humans and their geologic environment

mantle

The zone of the earth's interior between crust and core; rich in ferromagnesian silicates

The size of the earth's human population directly affects the severity of many environmental problems. Illustrate this idea in the context of (a) resources and (b) pollution.

Um... more people=more resources being used (fossil fuels, fresh water, biofuels, land); more people= more pollution (greenhouse gas emissions, waste like plastics, nutrient, heat, noise, light)