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7.3.9 Federal/National Programs
Bringing Into Being the Future We Wish to Live In
Canada’s Climate Models and Climate Change Scenarios are used world-wide!
Climate models are simplified mathematical representations of the Earth’s climate system. Complex equations are solved using a 3-D grid over the globe. Climate models try to simulate or imitate the components and processes at work in an actual climate system.
Climate models are designed to respond to changes internal changes in the climate system as well as external changes that are based on assumptions made by the scientists using the models. Climate change models can be used to run the scenarios needed for looking at future possibilities based on present and past knowledge. Teams of meteorologists, mathematicians and computer specialists have been developing climate models for forty years.
The basic model is known as the General Circulation Model or GCM. When factors from atmosphere (A), oceans and sea-ice linkages (O) are linked or coupled to the GCM. The models are called AOGCMs. The coupled models provide a more comprehensive simulation of a climate system. See the chart below showing the historical development of climate models. www.cccma.bc.ec.gc.ca/models. The third generation of AGCM’s is in the final stage of development and testing in 2005.
From IPCC 2001
The CGCM2 was used to run the 2001 IPCC report as well as the ongoing Arctic Climate Impact Assessment. The latest Canadian Global Coupled Model (CGCM2) has improved ocean-mixing limits and has added sea-ice dynamics. The more factors that are linked or coupled for consideration by the model, the closer the projections are to the natural conditions and events that affect climate. www.cccma.bc.ec.gc.ca
Scientists first include the physical properties of Earth, especially its oceans, ice and atmosphere, with their processes, reactions, interactions and feedback loops into the mathematical model. Climate models will become even more complex to include chemical and biological processes. www.dar.csiro.au/ccrp/index.html
Based on actual collected climate data, climate model predictions try to produce the best estimate of a future climate. Climate models are tested by using data from past climate records to predict known present observations. E.g. the model uses 1900-1920 temperatures to make projections of 1970-1990 temperatures. Such testing or validation increases the reliability of predictions made by the model.
The accuracy of the predicted results reflects the reliability the model will have. The latest models are now including temperatures from greater ocean depth limits and sea ice. Climate models allow scientists to move from known to unknown conditions using a validated model one built on solid data and tested performance.
For more details, see go to Contents 2.3
Also research the Canadian model for ocean behaviour developed in BC and now being used for Tsunami predictions.
Environment Canada developed the first index measurement tools for reporting solar radiation UV. This system is now uses world-wide. Canada also manages the international data for the world-wide UNEP program for UV.
for more information and the ‘Solar UV in our World’ on-line resource booklet developed by Association for Canadian Educational Resources (ACER) for the UV information and awareness program.
- List 4 components that were added to climate models after the early 1990s.
- Name 3 other countries that have international climate models.
- How are climate models validated?
- What are the most difficult components ie have the most variables – to add to a climate model?
|ACTIVITY 2 – Research