lesson 12- carbon cycle over time + L13- human vs natural

Question 1

how do we know what gases there were millions of years ago?

Answer 1

ice core samples are extracted from glaciers in Greenland and Antarctica, and the C02 levels are measured in a lab

Question 2

name 3 natural increases in CO2

Answer 2

volcanic eruptions
forest fires caused by lightning
the Milankovich cycle

Question 3

what is the Milankovich cycle

Answer 3

as earth gets closer to sun, and drifts away from a perfect orbit, earths temperature increases

Question 4

what is carbon concentration?

Answer 4

when the carbon cycle is undisturbed

Question 5

what is carbon sequestration?
give an example of carbon sequestration

Answer 5

saving of carbon
-fossil fuels:
plants -> coal
Animals die, sink, and are buried. The pressure causes them to turn into oil or gas

Question 6

give an example/ value to show how much fossil fuels we use

Answer 6

we use 100 million barrels of oil a day

Question 7

how much land do humans deforest a year

Answer 7

the size of Wales

Question 8

how does rising sea levels have a positive feedback loop?

Answer 8

people build sea walls
-sea walls use concrete
-concrete releases a large amount of CO2 when made

Question 9

what component of the cryosphere releases large amounts of methane when melted?

Answer 9

permafrost

Question 10

how much more effect does methane have on global warming than carbon dioxide?

Answer 10

21 times

Question 11

how do fungi and bacteria release CO2 and methane

Answer 11

they break down the carbon compounds in dead animals, converts it to carbon dioxide if oxygen is present, and methane if no oxygen is present

Question 12

how do wildfires and human fires release CO2?

Answer 12

fires consume biomassand organic matter to produce CO2, and the dead vegetation decomposes, releasing more CO2
-LICs burn wood and make fires as a heat/energy source- e.g. India, which has a lot of smog

Question 13

what is an example of a volcanic eruption?

Answer 13

1991 eruption of Mt Pinatubo- Philippines
- released more than 250 megatons of gas in one day. This is equal to 3 days worth of greenhouse gas emissions from the whole world
-shows humans have a greater influence of global warming, as this only happens every 20 ish years.

Krakatoa-released ash, which cooled earth by 1`C

Question 14

what food gives off a large amount of methane when made?

Answer 14

rice

Question 15

how much methane does a dairy cow produce in a year?

Answer 15

110kg methane
-same as 74 pigs
there are 264 million dairy cows