There are a diverse number of alerting systems in Canada, which reflects the challenges in reaching a small population spread over a very large geographic area. Canadian alerting systems align, like many things, with the structure of government: national, provincial/territorial, and local.
At the national level, there is the Alert Ready system. This system is primarily governed by the CRTC and incorporates public and private radio and television stations. Those warning sounds you hear on the radio, or when you see the red screen on your TV, are alerts that come from AlertReady. Environment Canada, sending tornado warnings, is the most frequent user of this system. The availability of AlertReady is fairly consistent across the country.
At the Provincial/Territorial level, there is less consistency. Some provinces such as Alberta and Saskatchewan, have developed comprehensive public alerting systems that expand the reach of alerts beyond what AlertReady offers, while still maintaining compatibility and integration with national goals. These provinces typically face more risks from emergency events and so have responded accordingly.
At the local level, there is very little consistency. Individual municipalities have established their own systems, typically in response to a recent emergency event, and are focused on local needs only. Compatibility and integration with national goals are usually not considered and there can be a disconnect between the information available through the national/provincial systems and the locally focused system.