Carbon cycle changes and feedback - P Flashcards
what is feedback
the balance between inputs and outputs in a system
what is dynamic equilibrium
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
what is an example of dynamic equilibrium
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
what is positive feedback
when effects are amplified (increasing) due to an imbalance in inputs and outputs e.g. global warming
what is negative feedback
when effects are reduced (nullified) due to an imbalance in inputs and outputs
what is a cascading system
an open system which forms a chain e.g. during the water cycle
what lead to feedback mechanisms
human and naturally induced changes in the carbon and water cycle
over the long term what do natural changes do to the Earth
they remain in a state of dynamic equilibrium
what do human changes do to the dynamic equilibrium
it takes the system out of balance - the rate that humans are impacting cycles in faster than the feedback mechanisms are happening
what are the two types of feedback loop
positive feedback
negative feedback
what is a negative feedback loop
the process that occurs is counteracted by an opposing process, causing the effect to cancel each other out and so nothing changes
what is a positive feedback loop
the process occurs, which causes another process to occur, which starts a chain reaction that enhances the first process
what are Boreal forests
those growing in high latitude environments where freezing temperatures occur for 6 to 8 months
what is ocean acidification
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
how has climate change affected carbon storage
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
what are critical thresholds
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
what could happen when thresholds are reached
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
what is happening to the rate of human induced climate change
the rate that it is occurring suggests tipping points will be reached and climate change will become more severe and fast paced
what is the mean temperature rise
1.2 degrees C rise - the warmest in 100,000 years
what has happened to warming over the past 50 years
over the past 50 years it has accelerated
what happens if we continue following the current path - climate change and GDP
we will see an 18% loss in GDP globally by 2050
how much heat humanly induced does the ocean absorb
90%
how much CO2 do we emit each year
40 billion tonnes
at the rate of 40 billion tonnes per year how many more years till carbon budget is used up
only 5 more years
