Planetary Boundaries Flashcards
Give a short definition of planetary boundaries
Planetary boundaries represent the limits within which humanity can safely operate to maintain a stable and resilient Earth system.
Name 5 of the 9 planetary boundaries
- Climate change
- Rate of biodiversity loss
- Nitrogen cycle & phosphorus cycle
- Stratospheric ozone depletion
- Ocean acidification
- Chemical pollution
- Atmospheric aerosol loading
- Change in land use
- Global freshwater use
Explain the photo
The inner green shading represents the proposed safe operating space.
The red wedges represent an estimate of the current position.
Crossed boundaries:
Climate change,
Nitrogen cycle,
Biodiversity loss
Close to being crossed:
Ocean acidification
Phosphorous cycle
How can we use the concept of planetary boundaries in environmental research?
The concept of planetary boundaries allows us to investigate if changes in earth systems will do any harm
What is nitrous oxide (N2O) and phosphorous used for and how do they impact the environment?
Nitrous oxide (N2O) and phosphorous are used for fertilizers in agriculture and can shift the state of lake and marine ecosystems from clear to turbid water and low levels of oxygen which can kill the fish.
How has the nitrogen cycle changed?
Human processes now convert more nitrogen from the atmosphere than all natural processes combined
How much do we need to cut in nitrogen emissions to get within the planetary boundary?
We need to cut nitrogen so we use 25% of what we use today
We need to cut on fertilizers
How much phosphorus can we convert before we reach the planetary boundary in this area?
No more than 10 times the natural background rate
What are the effects of biodiversity loss?
Biodiversity loss reduces the capacity of ecosystems to provide services such as:
- soil fertility
- climate regulation
- natural pest controls
This affects agriculture, water resources, climate stability, and human health
What are the main causes of biodiversity loss?
MAIN CAUSES (in order):
* changes in land use
* climate change
* excessive nutrients
* introduction of new species
How much has the total number of insects declined from 1990 to 2020?
25%
How has the wildlife population developed since the 70’s?
Wildlife populations are declining across the globe but falling especially steeply in tropical regions.
In Latin America and the Caribbean, wildlife populations have experienced a 94% decline since 1970 :(
How is the evidence on climate change caused by humans?
There is compelling, comprehensive, and consistent objective evidence that humans are changing the climate in ways that threaten our societies and the ecosystems on which we depend.
How has human activity lead to climate change?
By altering the composition of the global atmosphere (greenhouse gasses). The most important GHG is carbon dioxide (CO2) which is produced by combustion processes
What is the planetary boundary of climate change?
Atmospheric concentrations of carbon dioxide (CO2) should not exceed 350 p.p.m.v. (=parts per million by volume of air)
