ecosystem feedbacks on climate change Flashcards
What is a carbon flux?
A carbon flux refers to the amount of carbon exchanged between carbon pools over a specified time. It is the movement of carbon between land, oceans, atmosphere, and living things.
Carbon fluxes are typically measured in Gt C/yr or Tg CO2/yr.
What are carbon pools?
Carbon pools are reservoirs of carbon that can both take in and release carbon.
The main carbon pools in the Earth System are Ocean, Terrestrial Ecosystems, Earth’s crust (sedimentary rocks), and Atmosphere, measured in gigatonnes (GtC).
How does the geological carbon cycle work?
The cycle starts in the atmosphere, where acid forms by a reaction with CO2 and water. This weakly acidic water reacts with minerals, dissolving them through chemical weathering, and the ions are carried to the ocean, where they precipitate as minerals like calcite. This calcite forms limestone and can return to the atmosphere as CO2 through volcanic eruptions or seeps.
Weathering, subduction, and volcanism control atmospheric carbon dioxide concentrations over hundreds of millions of years.
Why are forests not considered the ‘lungs of the Earth’?
While plants absorb CO2 and produce oxygen through photosynthesis, almost all oxygen produced is consumed by the plant itself or by decomposers. Forest fires also consume oxygen, leading to a net production of oxygen close to zero.
Therefore, forests do not produce oxygen and cannot be considered the lungs of the Earth.
How can the geological carbon cycle sequester carbon via enhanced rock weathering?
The weathering process can be accelerated by milling rocks to fine grains, increasing their surface area for faster reactions. Spreading rock dust on soils of managed croplands can help sequester carbon.
This can be combined with other carbon removal options, such as planting trees.
What does Net Zero mean?
Net zero refers to the balance between the amount of greenhouse gas produced and the amount removed from the atmosphere. It is achieved when the amount added is no more than the amount taken away.
What is climate intervention?
Climate intervention refers to purposeful actions intended to produce a targeted change in some aspect of the climate, including carbon sequestration and solar radiation management.
It does not include efforts to limit emissions of greenhouse gases.
What is solar radiation management?
Solar radiation management involves intentional efforts to increase the amount of sunlight that is reflected back to space, reducing sunlight absorption by Earth.
Examples include injecting aerosols into the stratosphere and marine cloud brightening.
What does Carbon Dioxide Removal (CDR) consist of?
CDR consists of intentional efforts to remove carbon dioxide from the atmosphere through various strategies, including land management, accelerated weathering, and direct air capture.
CDR techniques complement carbon capture and sequestration methods.
What are land-based CDR strategies?
Land-based CDR strategies are practices that increase carbon storage in living plants or sediments.
Examples include coastal blue carbon, peatland restoration, afforestation/reforestation, and soil carbon management.
