Why do we use the unit of the “Joule”? Figure 4.1: U.S. household energy consumption by end use. 1 Quad = 1015 Btu. The physicist James Joule (1843) discovered that the amount of energy needed to raise the temperature of water was the same whether it was work done on the water or heat added.

Joule’s mechanical heating apparatus (1845) First Law of Thermodynamics: Heat = Work W = ΔE = ΔTE Figure 4.1: U.S. household energy consumption by end use. 1 Quad = 1015 Btu.

So, how much heat do you need to add to raise the temperature of 1 gram of something 1°C? Figure 4.1: U.S. household energy consumption by end use. 1 Quad = 1015 Btu.

This is how the “calorie” and “Btu” were defined! 1 calorie = energy required to raise 1 gram of water 1°C 1 Btu (British thermal unit) = energy required to raise 1 pound of water 1°F

This is how the “calorie” and “Btu” were defined! 1 calorie = energy required to raise 1 gram of water 1°C 1 Btu (British thermal unit) = energy required to raise 1 pound of water 1°F It takes 4.184 j to raise 1 gm of water 1°C (or, 4.184 kJ to raise 1 kg of water 1°C)

But it depends on the substance!!! Q = mcΔT Heat added = (mass)(specific heat)(change in T)

What are some consequences of this for climate and climate change?

Figure 4. 1: U. S. household energy consumption by end use Figure 4.1: U.S. household energy consumption by end use. 1 Quad = 1015 Btu.

Demonstration on converting chemical energy to heat:

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml)

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C What is the specific heat of water? c = 1 cal/g/°C

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C What is the specific heat of water? c = 1 cal/g/°C How much heat was added to the water?

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C What is the specific heat of water? c = 1 cal/g/°C How much heat was added to the water? Q = mcΔT

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C What is the specific heat of water? c = 1 cal/g/°C How much heat was added to the water? Q = mcΔT = (250 g)(1 cal/g/°C)(11.1°C) = 2,780 cal

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C What is the specific heat of water? c = 1 cal/g/°C How much heat was added to the water? Q = mcΔT = (250 g)(1 cal/g/°C)(11.1°C) = 2,780 cal What is this in Calories?

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C What is the specific heat of water? c = 1 cal/g/°C How much heat was added to the water? Q = mcΔT = (250 g)(1 cal/g/°C)(11.1°C) = 2,780 cal What is this in Calories? 2.78 (1 Calorie = 1 kilocalorie = 1000 calories)

Calories in a Hershey bar: (1.55 oz) 230 Calories = 230,000 calories

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C What is the specific heat of water? c = 1 cal/g/°C How much heat was added to the water? Q = mcΔT = (250 g)(1 cal/g/°C)(11.1°C) = 2,780 cal What is this in Calories? 2.78 (1 Calorie = 1 kilocalorie = 1000 calories) What is this in joules?

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C What is the specific heat of water? c = 1 cal/g/°C How much heat was added to the water? Q = mcΔT = (250 g)(1 cal/g/°C)(11.1°C) = 2,780 cal What is this in Calories? 2.78 (1 Calorie = 1 kilocalorie = 1000 calories) What is this in joules? 11,600 j (2780 cal x 4.184 j/cal = 11,600 j)

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C What is the specific heat of water? c = 1 cal/g/°C How much heat was added to the water? Q = mcΔT = (250 g)(1 cal/g/°C)(11.1°C) = 2,780 cal What is this in Calories? 2.78 (1 Calorie = 1 kilocalorie = 1000 calories) What is this in joules? 11,600 j (2780 cal x 4.184 j/cal = 11,600 j) How many Calories in 1 average hazelnut?

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C What is the specific heat of water? c = 1 cal/g/°C How much heat was added to the water? Q = mcΔT = (250 g)(1 cal/g/°C)(11.1°C) = 2,780 cal What is this in Calories? 2.78 (1 Calorie = 1 kilocalorie = 1000 calories) What is this in joules? 11,600 j (2780 cal x 4.184 j/cal = 11,600 j) How many Calories in 1 average hazelnut? 8.8 Cal

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C What is the specific heat of water? c = 1 cal/g/°C How much heat was added to the water? Q = mcΔT = (250 g)(1 cal/g/°C)(11.1°C) = 2,780 cal What is this in Calories? 2.78 (1 Calorie = 1 kilocalorie = 1000 calories) What is this in joules? 11,600 j (2780 cal x 4.184 j/cal = 11,600 j) How many Calories in 1 average hazelnut? 8.8 Cal How efficient was the conversion?

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C What is the specific heat of water? c = 1 cal/g/°C How much heat was added to the water? Q = mcΔT = (250 g)(1 cal/g/°C)(11.1°C) = 2,780 cal What is this in Calories? 2.78 (1 Calorie = 1 kilocalorie = 1000 calories) What is this in joules? 11,600 j (2780 cal x 4.184 j/cal = 11,600 j) How many Calories in 1 average hazelnut? 8.8 Cal How efficient was the conversion? 2.78 Cal/8.8 Cal = 32%

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C What is the specific heat of water? c = 1 cal/g/°C How much heat was added to the water? Q = mcΔT = (250 g)(1 cal/g/°C)(11.1°C) = 2,780 cal What is this in Calories? 2.78 (1 Calorie = 1 kilocalorie = 1000 calories) What is this in joules? 11,600 j (2780 cal x 4.184 j/cal = 11,600 j) How many Calories in 1 average hazelnut? 8.8 Cal How efficient was the conversion? 2.78 Cal/8.8 Cal = 32% Where is the rest of the energy?

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C What is the specific heat of water? c = 1 cal/g/°C How much heat was added to the water? Q = mcΔT = (250 g)(1 cal/g/°C)(11.1°C) = 2,780 cal What is this in Calories? 2.78 (1 Calorie = 1 kilocalorie = 1000 calories) What is this in joules? 11,600 j (2780 cal x 4.184 j/cal = 11,600 j) How many Calories in 1 average hazelnut? 8.8 Cal How efficient was the conversion? 2.78 Cal/8.8 Cal = 32% Where is the rest of the energy? (lots of places!)

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C What is the specific heat of water? c = 1 cal/g/°C How much heat was added to the water? Q = mcΔT = (250 g)(1 cal/g/°C)(11.1°C) = 2,780 cal What is this in Calories? 2.78 (1 Calorie = 1 kilocalorie = 1000 calories) What is this in joules? 11,600 j (2780 cal x 4.184 j/cal = 11,600 j) How many Calories in 1 average hazelnut? 8.8 Cal How efficient was the conversion? 2.78 Cal/8.8 Cal = 32% Where is the rest of the energy? (lots of places!) What is the typical efficiency of an electricity power plant?

Demonstration on converting chemical energy to heat: Amount of water: 250 g ( = 250 ml) Change in temperature: 31.7°C – 20.6°C = 11.1°C What is the specific heat of water? c = 1 cal/g/°C How much heat was added to the water? Q = mcΔT = (250 g)(1 cal/g/°C)(11.1°C) = 2,780 cal What is this in Calories? 2.78 (1 Calorie = 1 kilocalorie = 1000 calories) What is this in joules? 11,600 j (2780 cal x 4.184 j/cal = 11,600 j) How many Calories in 1 average hazelnut? 8.8 Cal How efficient was the conversion? 2.78 Cal/8.8 Cal = 32% Where is the rest of the energy? (lots of places!) What is the typical efficiency of an electricity power plant? ~30-35%

Table 3-4a, p. 90

Table 3-4b, p. 90

Table 3-4c, p. 91

Table 3-4d, p. 91

Earth’s animal populations declined by more than half (52%) during 1970-2010

One and a half Earth’s are now needed to meet humans’ current demands

Table 3-4d, p. 91

Some animals are doing well. Some are doing very poorly.

Some Animals are doing well in human habitats:

Some Animals are doing well in human habitats:

Some Animals are doing well in human habitats:

Table 3-4d, p. 91

Earth’s animal populations declined by more than half (52%) during 1970-2010

Where do you think animal populations are decreasing the fastest? Land, Freshwater, Ocean water

Land animals: 39% decrease

Marine animals: 39% decrease Table 3-4d, p. 91

Freshwater animals: 76% decrease

Carbon (from burning fossil fuels) dominates the global human ecological footprint

Total ecological impact = = (footprint per person) x (number of people)

Total ecological impact = = (footprint per person) x (number of people)

Impact by Country: Shows political influence

Impact per person: shows regional standards of living

Impact per person: shows regional standards of living

Currently, no country is below the sustainable ecological footprint (per person) and above the Human Development Index (IHDI) Table 3-4d, p. 91

Power use per person per day, by Country (2007) Figure 4.1: U.S. household energy consumption by end use. 1 Quad = 1015 Btu.

Biocapacity has been increasing, but not as fast as population

The Future is portrayed very differently in fiction: Utopia vs The Future is portrayed very differently in fiction: Utopia vs. Dystopia

The Future is portrayed very differently in fiction: Utopia vs The Future is portrayed very differently in fiction: Utopia vs. Dystopia

The Future is portrayed very differently in fiction: Utopia vs The Future is portrayed very differently in fiction: Utopia vs. Dystopia

The Future is portrayed very differently in fiction: Utopia vs The Future is portrayed very differently in fiction: Utopia vs. Dystopia

How optimistic are you of the human race (1000 years from now)? Utopia Dystopia 1 2 3 4 5 6 7 8 9 10 What are the top three threats to the human race? 1. 2. 3.