Future Climates Flashcards
What are Global Climate Models (GCMs)
Gridded, mathematically derived interpretations of both past and future climates
What are the initial inputs of GCMs?
the mathematical formulas are transferred to computer algorithms to interpret the given conditions at the start of the simulation
What are the forcing mechanisms of a GCM
the recalculation using changes in the atmosphere that are thought to be recurring
What is the most important part of a GCM scenario?
initial inputs - if they are flawed, the output can be flawed too
How would the modelers verify the GCM
- They need to be able to model past climates from historical data
for example: go back 100 years in history in a region. Use the first 50 years of data to calibrate the model, then run the model and compare the model to the actual data.
What is the issue with using the historical data for verification? How have they filled in the gaps?
Historical data is only available from long-term climate stations. Spatially, the long term stations are a poor representation of the globe
To fill in the gaps, paleoclimatological data (ocean deposits, ice cores, coral reefs, pollen and tree ring data) is added to historical data to get approximate past climate
Since each country had their own models, how did they relate them to each other?
Intergovernmental Panel on Climate Change (IPCC) developed a set of standards so that the modelers could compare results.
What were the top five countries in modeling?
Canada
Germany
Japan
United Kingdom
United States
What were the standards the IPCC set?
The IPCC developed a set of past climatic conditions that the GCM modelers must be able to predict
How did the models differ in future climates? What standard did the IPCC set for CO2 levels?
- The IPCC set the standards for 1990 CO2 levels + 1% each year
- No two models were identical but many models predicted the same things, just different magnitudes.
Early Canadian models were simple in form: what types of layers did it consist of?
Each layer could relate to the layer immediately adjacent to itself
- 5 vertical layers
- 4 atmospheric layers
- 1 ocean layer: static (no modeled currents)
The first generation model was __ x __ degree grid
__ x __ grids for a total of ____ grid cells
3.75 x 3.75 degree grid
48 x 96 = 4609 grid cells
How did the Canadian 2nd generation models differ from 1st generations?
- 10 vertical layers (vs 5)
- 7 atmospheric layers (vs 4)
- 3 ocean layers (vs 1)
- each layer could relate to two layers adjacent to itself compared to just one in the 1st generation
How complex were the 3rd generation models?
- 32 vertical layers
- each layer can relate to four layers immediately adjacent to itself
- deep ocean processes were modeled as well as soil moisture, transpiration, and humidity effects
How large was each cell in third generation models? And how many total cells?
2.65 x 2.65 (compared to 3.75 x 3.75 in first generation)
5216 x 32 = 166,912 cells
Why was there more efforts put into regional models than global models?
The wars forced a more regional approach
- higher resolution than GCM (10km x 10km) and less complex systems
When did modelling in Canada stop?
2013
Special Report on Emissions Scenario (SRES) modeled GHG effects: what were the 5 main driving force for increased GHG effects
- Population growth
- Narrowing of income distribution
- Range of assumptions about energy system developments and land-use patterns
- Different assumptions about deforestation and afforestation
What was the reliability of the SRES models?
- All models were based on fundamental physical laws and well-established relationships
- The models were run for climates of recent past, and if they did a good job representing these climates, they are allowed to move further in time
What effect did the Representative Concentration Pathways (RCPs) have on GHG emissions?
- Moved away from country emissions and toward total GHG emissions
- Updated the IPCC report in 2014
What was the point in Shared Socioeconomic Pathways (SSPs)
- Described socioeconomic paths
- Used qualitative storylines to describe scientific numbers
- Updated IPCC report in 2021
What was the atmospheric CO2 as of February 2024?
427.09 ppm
