Unit 7: Water & Carbon Cycle Flashcards
(27 cards)
How much have global temperatures increased since the 1880s?
1.5°C
Why have global temperatures increased? (Hint: gases)
The cause of ‘global warming’ is
linked to increased concentrations of greenhouse gases within the atmosphere, namely Carbon Dioxide CO2 and Methane CH4.
Methane is the second most important greenhouse gas. Approximately 60 % of methane emissions come from human activities such agriculture. The rest is from natural decomposition of
organic matter.
As a greenhouse gas, a methane molecule is __ times more potent
that CO2
25
What is the main impact of peat extraction on the carbon cycle?
Peat extraction releases stored carbon into the atmosphere, increasing CO₂ emissions and contributing to climate change.
How does drainage of peatlands affect the water cycle?
Draining peatlands reduces water retention, increases runoff, and disrupts natural filtration, leading to drier soils.
What restoration methods help reduce carbon emissions from peatlands?
Blocking drainage channels, rewetting the land, and reintroducing sphagnum moss help maintain peatland carbon storage.
How does burning peat as fuel impact the environment?
Burning peat releases large amounts of CO₂ and removes an important natural carbon store, accelerating climate change.
What government policies support peatland restoration?
The UK’s Net Zero strategy includes land use changes, peatland protection, and reduced peat-based horticulture.
What is the Energy Budget?
The ‘Energy Budget’ is the **balance between incoming radiation$* from the sun and outgoing radiated heat plus reflected radiation from the sun.
Key concepts:
• The incoming energy from the sun is in the form of light energy (shortwave radiation). This energy is referred to as insolation (incoming solar radiation).
• Only about half of the insolation reaching the outer atmosphere reaches and is absorbed by Earth’s surface. This is because as the insolation passes through the atmosphere, some reflected and scattered back into space, whilst some is absorbed in the atmosphere.
• Most of the isolation that reaches the Earth’s surface is absorbed and
converted into heat energy (long wave radiation); some is reflected. This heat energy radiates outwards and some is trapped by greenhouse gasses, warming the atmosphere.
The heat stored in the atmosphere either gets transferred back to the Earth’s surface or radiates out into space.
Impacts of increasing Atmospheric Carbon?
• Changes to patterns and levels of precipitation/extreme weather events and river discharge
• Sea level rise and acidification of the oceans
What is an example of extreme flooding?
The 2010 Pakistan Floods, which affected over 20 million people due to unprecedented monsoon rains, causing severe damage to infrastructure and agriculture.
What is an example of extreme precipitation?
The 2013 Colorado Floods, where intense rainfall caused widespread flooding, destroying homes, roads, and bridges, leading to mass evacuations.
What is an example of a severe drought?
The California Drought (2012-2016), a prolonged water shortage that led to agricultural losses, wildfire outbreaks, and strict water restrictions.
What is an example of a devastating forest fire?
The 2019-2020 Australian Bushfires (“Black Summer”), which burned millions of hectares, destroyed thousands of homes, and caused severe wildlife loss.
How did the 2019–2020 Australian wildfires impact the carbon cycle?
• Released massive amounts of CO₂ from burning forests and peatlands.
• Reduced carbon sequestration as trees and vegetation were destroyed.
• Ash and smoke affected atmospheric chemistry, altering regional climate patterns.
• Led to long-term shifts in carbon absorption rates due to ecosystem degradation.
What effect did Hurricane Katrina (2005) have on carbon storage?
Destroyed large coastal forests, reducing their ability to sequester carbon and releasing CO₂ from decomposing vegetation.
What is a feedback system?
A feedback system is a series of responses that change the ‘steady-state equilibrium’ of a system.
What is a positive feedback system?
Positive feedback- when a series of responses increases or amplifies the initial change.
Think of it as being like a ‘domino effect’.
What is a negative feedback system?
Negative feedback - when a series of responses stops or reverses the initial change.
As a result, equilibrium could be restored.
How does positive feedback amplify climate change? (Relating to water vapour)
Increased global temperatures cause ice caps to melt, reducing Earth’s reflectivity.
Less ice means more heat absorption, leading to further warming.
This process accelerates climate change by reinforcing the initial warming effect.
How does negative feedback regulate the carbon cycle?
Higher atmospheric CO₂ levels promote increased plant growth through photosynthesis.
More plants absorb CO₂, reducing overall greenhouse gas concentrations.
This helps stabilize climate change by counteracting carbon emissions.
How does the methane feedback loop amplify climate change?
Rising global temperatures cause permafrost to melt, releasing methane (CH₄) stored in frozen ground.
Methane is a potent greenhouse gas, trapping more heat than CO₂.
Increased atmospheric methane leads to further warming, accelerating permafrost thaw.
This cycle continues, reinforcing the effects of climate change.
How does the cryosphere feedback loop accelerate warming?
Rising temperatures melt ice, reducing Earth’s reflectivity (lower albedo).
Less ice means more heat absorption, causing further warming.
Thawing permafrost releases methane (CH₄), intensifying greenhouse effects.
