Carbon cycle changes and feedback

Question 1

what is feedback

Answer 1

the balance between inputs and outputs in a system

Question 2

what is dynamic equilibrium

Answer 2

when there is no feedback as the inputs are equal to the outputs so the stores stay the same as they don’t increase or decrease

Question 3

what is an example of dynamic equilibrium

Answer 3

a glacier as the ice can melt and evaporate but freeze at the same rate so there is always the same amount of inputs and outputs

Question 4

what is positive feedback

Answer 4

when effects are amplified (increasing) due to an imbalance in inputs and outputs e.g. global warming

Question 5

what is negative feedback

Answer 5

when effects are reduced (nullified) due to an imbalance in inputs and outputs

Question 6

what is a cascading system

Answer 6

an open system which forms a chain e.g. during the water cycle

Question 7

what lead to feedback mechanisms

Answer 7

human and naturally induced changes in the carbon and water cycle

Question 8

over the long term what do natural changes do to the Earth

Answer 8

they remain in a state of dynamic equilibrium

Question 9

what do human changes do to the dynamic equilibrium

Answer 9

it takes the system out of balance - the rate that humans are impacting cycles in faster than the feedback mechanisms are happening

Question 10

what are the two types of feedback loop

Answer 10

positive feedback
negative feedback

Question 11

what is a negative feedback loop

Answer 11

the process that occurs is counteracted by an opposing process, causing the effect to cancel each other out and so nothing changes

Question 12

what is a positive feedback loop

Answer 12

the process occurs, which causes another process to occur, which starts a chain reaction that enhances the first process

Question 13

what are Boreal forests

Answer 13

those growing in high latitude environments where freezing temperatures occur for 6 to 8 months

Question 14

what is ocean acidification

Answer 14

when the ocean takes in CO2 it reacts with seawater to release hydrogen ions which lower the pH of the ocean, making it more acidic

Question 15

how has climate change affected carbon storage

Answer 15

more CO2 in the atmosphere (so can be absorbed by the ocean) which reacts with seawater to produce hydrogen ions which compete with shells for carbonate so less is stored in shells. The acidic waters also can kill sea plants so less CO2 is stored in plants

Question 16

what are critical thresholds

Answer 16

a boundary which when exceeded can lead to a significant change in the state of the system, often with an understanding that the change is irreversible

Question 17

what could happen when thresholds are reached

Answer 17

once tipping points/thresholds are reached the changes in the global carbon and climate system could be irreversible and trigger unpredictable or extreme further changes

Question 18

what is happening to the rate of human induced climate change

Answer 18

the rate that it is occurring suggests tipping points will be reached and climate change will become more severe and fast paced

Question 19

what is the mean temperature rise

Answer 19

1.2 degrees C rise - the warmest in 100,000 years

Question 20

what has happened to warming over the past 50 years

Answer 20

over the past 50 years it has accelerated

Question 21

what happens if we continue following the current path - climate change and GDP

Answer 21

we will see an 18% loss in GDP globally by 2050

Question 22

how much heat humanly induced does the ocean absorb

Answer 22

90%

Question 23

how much CO2 do we emit each year

Answer 23

40 billion tonnes

Question 24

at the rate of 40 billion tonnes per year how many more years till carbon budget is used up

Answer 24

only 5 more years

Question 25

which rainforest is reaching its tipping point

Answer 25

the Amazon Rainforest

Question 26

what will happen to the rainforest at the tipping point

Answer 26

if too much primary tree cover is lost it will transition into a savannah and have little effectiveness as a carbon sink

Question 27

when will the Amazon become a savannah - forest %

Answer 27

when 25% of the forest is lost (currently at 20%)

Question 28

what does the thermohaline circulation cause

Answer 28

cooling in higher latitudes and warming at the equator

Question 29

what happens if the thermohaline circulation reaches its tipping point

Answer 29

the effects will be exaggerated

Question 30

are human induced changes long or short term

Answer 30

short term as emissions of CO2 started around 1750 whereas glacial and interglacial cycles are over thousands of years

Question 31

are human induced changes becoming long term effects

Answer 31

yes - given the extent and rate that they are occuring