1.2 & 1.3 Natural & Global Climate Change

Question 1

Natural Causes of Climate Change

Answer 1

Climate change refers to the average global temperature. Temperatures have shifted from glacial to non glacial periods over time. Global Warming has slowly happened over 110,000 years. Last glacial period was 15,000 years ago. The Earth has been warming quicker ever since then

Question 2

Natural Causes of Climate Change Continue

Answer 2

The eccentricity of the Earth’s rotation around the sun causes variation in the Earth’s climate because it changes how hot or cold the Earth is. This is how glacial periods happen. Another reason is the Earth’s tilt. Because of the tilt, the climates N + S of the equator change every 40,000 years

Question 3

Orbital Change

Answer 3

Eccentricity (Stretch) - The orbit around the dun changes from circular to oval every 100,000 years, causing glacial periods
Tilt - Earth is tilted at roughly 23°. This creates seasons N & S of the equator, especially at the Poles. These change every 40,000 years
Precession (Wobble) - The Earth “wobbles” on its axis, like a spinning top, and it changes every 22,000 years

Question 4

Asteroid Collisions

Answer 4

Dust in the air to block solar heat - cause glacial periods. They have a dramatic effect on life. 65m years ago the dinosaurs became extinct from the change in climate after the asteroid hit

Question 5

Volcanic Activity

Answer 5

Ejects ash into atmosphere. Blocks solar radiation. Short terms changes in climate - Mt. Tambora in 1815 caused the “Year without a Summer” in 1816

Question 6

Solar Output Variation

Answer 6

Changes in short cycles, about every 11 years. Long cycles over hundreds of years. Solar output reduces causes the Earth to cool. Maunder minimum reduced solar activity from 1645 - 1715 which caused the “Little Ice Age”

Question 7

Tree Rings

Answer 7

Each ring shows 1 year of growth
Thicker ring = Wetter year with more sunlight
Thinner ring = Dryer year and extreme sunlight / coldness
Scars = Forest fires caused from extremely dry conditions

By looking at tree rings you can see what type of climate it was each year. Forest fire scars suggest extreme heat and no rain

Question 8

Ice Cores

Answer 8

Oxygen + CO2 = The make up of the atmosphere
Pollution = Shows how “healthy” the Earth was
Volcanic ash = Shows whether it was a warm or cold period

Question 9

Historical Sources (Old Photos, Drawings, Records etc)

Answer 9

1550 - 1850 shows the “Little Ice Age” in the UK - Temperatures froze the Thames and people held fairs on it
1683 - 1684 shows the Thames was frozen with 28cm of ICE. Theft of crops could be reason for a bad harvest

Question 10

Human Climate Change

Answer 10

The greenhouse effect is completely natural
The greenhouse effect stops the Earth fro, becoming a frozen wasteland
CO2 is the most common greenhouse gas

Question 11

Agriculture

Answer 11

Trees absorb + store CO2. However population growth and demand for food has led to deforestation and clearing for cattle and rice farming. Deforestation stops the absorption of CO2, which leaves more CO2 in the atmosphere. Furthermore, human activities produce methane which is 21 times more powerful than CO2. These powerful greenhouse gases enhance the greenhouse effect and cause Global Warming

Question 12

Energy

Answer 12

CO2 is released when fossil fuels are burnt. There has been a 30% increase in CO2 since 1850 because of the increase in deforestation and the burning of fossil fuels. This happens because the demand for power has increased with the population increase and advancing technology. That’s why electricity effects the greenhouse effect

Question 13

Transport

Answer 13

CO2 is released from fossil fuels in most forms of transport. Since 1850 there has been a 16% increase in nitrous oxide. This happens because more countries are developing and have a need for transport. This means more forms of transport are used, releasing more CO2

Question 14

Industry

Answer 14

Most industrial industries use halocarbons. This causes more Global Warming because they’re 3,000 times more powerful than CO2. Because people have a demand for more products, usage of halocarbons is increased, causing an increase in Global Warming. As the demand increases, more industrial buildings are made, causing more halocarbons to be used

Question 15

Evidence to support Human Global Climate Change

Answer 15

Causing the Arctic to melt - ships can now travel from Rotterdam to Yokohama much quicker because they don’ have to go around Africa. This is still bas because of rising sea levels

Temperature increase - makes areas much dryer so crops can’t grow. Harder for farmers in low altitude but easy for farmers in high altitude

Rising sea levels - coastal flooding and flooding farms at low altitude. Low altitude cities i.e New York could be flooded if seas keep riding in 100 years, meaning more cities will have to be built causing more flooding

Question 16

Projections for Global Temp Change + Sea Level Rise

Answer 16

Countries could use clean energy
We don’t know when Antartica will melt
Winds aren’t necessarily going to raise the sea level

High population growth - increase global temp. Areas will need to use more energy, which could release CO2. Ozone layer will decay and the sun will heat up the Earth very quickly

Low population growth - slowly increase global temp. Over time greenhouse gases will be released from creating buildings and using transport. This will heat up the Earth