Please Answer This Question
E-103: The Challenge of Human Induced Climate Change: Transitioning to a Post Fossil Fuel Future
Homework Set #2 Energy Basics DUE Tuesday, 3/9 (12:00 pm online)
Name: _____________________________________ Score: ______/_______
In order to understand Earth’s climate and how it is influenced by our energy choices, it is important to understand basic principles of energy, heat, temperature, and water. In this assignment, you’ll also see how the carbon cycle (both natural and anthropogenic) is intimately tied to energy and climate. You will visit a few websites in order to expose you to some of the energy and climate data available to you.
Conceptual and quantitative problems. You will only receive credit if you show all your work and write legibly.
I. Defining energy
1. Energy is the ability to do ________________. It is neither _______________ nor _________________, but changes __________________. [1 point]
II. Properties of Water
2. Label the phases of water in the following figure. [1 point]
3. The figure below shows a phase diagram for water. Remember that the atmospheric pressure at sea level is about 1 atm. [2 points]
a. Label the three phases.
b. On the temperature axis, correctly label 0°C and 100°C.
4. True or False. Warmer air can hold more water vapor. [1 point]
III. Latent and Sensible Heat
5. ________________heat is required to change the temperature of water. ___________________ heat is involved in changing the phase of water. [1 point]
IV. Heat Capacity and Specific Heat (Heat capacity per unit mass)
6. Water, air, and land heat up at different rates, which is evident when you jump from a hot concrete pool deck into a pool in the summer. These differences are very important in global weather patterns and the distribution of energy around the planet. The specific heats and densities are listed in the table below.
a. How much energy is required to raise the temperature of 1 cubic meter of water, air, and land by 10°C? Show your work and report your answers in Joules in the table below. [3 points]
b. Imagine a cubic meter of water, air and land were each exposed to the same amount of solar energy (340 W m-2). The surface area intercepting the solar energy for each substance is 1 m2. How long would it take to increase the temperature of each material by 10°C? Show your work and report your answer in hours in the table. [3 points]
Material | Density at 20°C, sea level (kg/m3) | Specific Heat Capacity (Joules/kg °C) | Energy required to raise temp of 1 m3 by 10°C (Joules) | Solar heating time (hours) |
Water | 998.2 | 4182 | ||
Air | 1.2041 | 1005 | ||
Land* | 3000 | 850 |
*Based on a range of values for different types of rock, just for rough estimates.
c. Think about how your calculations impact energy movement on the global scale. Based on your calculations, do the oceans or continents heat up more quickly? When the energy source is reduced (daily or seasonal cycles), would oceans or continents cool off the fastest? [2 points]
d. In the northern hemisphere, are surface winds (think about the pressure differences that drive winds) more likely to blow from the land toward the ocean in June or in November? Why? Use a diagram to explain your answer. [2 points]
V. Carbon Cycle
7. The process by which energy is stored in organic carbon compounds is _______________________________. The reverse process, in which energy is released from organic carbon compounds is called _______ _____________________________. [1 point]
8. Using the carbon cycle figure below, calculate the average residence time of carbon in each of the following reservoirs. Report your answers in years.
a. Define residence time using an equation and in your own words. [1 point]
b. Deep ocean [0.5 points]
c. Soil [0.5 points]
d. Atmosphere [0.5 points]
e. Sediments [0.5 points]
9. Understanding carbon storage and release
a. The carbon in fossil fuels (coal, oil, and natural gas) belongs to which reservoir? [1 point]
b. Briefly explain the two processes by which carbon enters “long term storage” in the sedimentary reservoir. [2 points]
c. What is the role of plate tectonics in returning carbon from the sedimentary reservoir to the atmosphere? [1 point]
d. What is the role of humans in returning carbon from the sedimentary reservoir to the atmosphere? [2 points]
10. Through fossil fuel use, humans are significantly accelerating the rate at which ancient carbon in the sedimentary reservoir is being returned directly to the atmosphere. Assume that the human rate of transfer of carbon from sediments to the atmosphere is 50 times that of the pre-industrial rate of 0.23 Gt C per year. Since the industrial revolution, humans have added a total of 200 Gt C to the atmospheric reservoir (an increase from about 280 to 390 ppm CO2). If we were to stop burning fossil fuels right now and switch to a zero-carbon economy, how long would it take for the additional 200 Gt C to be removed from the atmosphere-land-ocean system and returned to the long-term sediment reservoir? Assume a rate of 0.23 g/year into the sediment. [1 point]
11. Navigate to the NOAA Carbon Tracker website: https://www.esrl.noaa.gov/gmd/ccgg/carbontracker/.
a. Read the Global CO2 Budget section and study Figure 1. What are the two major sources and two major sinks shown in the figure? [2 points]
b. What is proposed as the cause for the decrease in fossil fuel CO2 emissions in 2008 and 2009? Explain why this is the case. [1 point]