diff --git a/google/api_core/client_logging.py b/google/api_core/client_logging.py
index d3cf805a..35938ce7 100644
--- a/google/api_core/client_logging.py
+++ b/google/api_core/client_logging.py
@@ -1,84 +1,73 @@
 import logging
 import json
 import re
+import os
 
-# NOTE: We can essentially just use `json.dumps` and make structured logging our default format.
-class DefaultFormatter(logging.Formatter):
-    def format(self, record):
-        # Base format with time, severity, and main message
-        # base_message = f"{self.formatTime(record)} - {record.levelname} - {record.name} - {record.getMessage()}"
-        base_message = super().format(record)
-        
-        # Add any extra fields below:
-        extra_info = []
-        if hasattr(record, 'client_id'):
-            extra_info.append(f"client_id={record.client_id}")
-        if hasattr(record, 'response_id'):
-            extra_info.append(f"client_id={record.client_id}")
-        if hasattr(record, 'httpRequest'):
-            extra_info.append(f"httpRequest={record.httpRequest}")
-        if hasattr(record, 'json_fields'):
-            for key, val in record.json_fields.items():
-                extra_info.append(f"{key}={val}")
-        
-        # Combine base message with extra fields
-        if extra_info:
-            base_message += " | " + " - ".join(extra_info)
-        
-        return base_message
+LOGGING_INITIALIZED = False
 
+# TODO(<add-link>): Update Request / Response messages.
+REQUEST_MESSAGE = "Sending request ..."
+RESPONSE_MESSAGE = "Receiving response ..."
 
-# NOTE: Option 1: Allow users to configure log levels.
-# def setup_logging(log_level, namespace="google"):
-    
-#     # NOTE: A logger with namespace="google" is only configured if all of the below conditions hold true:
-#     # - A root logger is not configured.
-#     # - N/A: A logger with namespace="google" is not already configured (This statement is removed.)
-#     # - GOOGLE_SDK_PYTHON_LOGGING_LEVEL is set.
-#     if not logging.getLogger().hasHandlers() and log_level:
+# TODO(<add-link>): Update this list to support additional logging fields
+_recognized_logging_fields = ["httpRequest", "rpcName", "serviceName"] # Additional fields to be Logged.
 
-#         # define a module for our repositories
-#         logger = logging.getLogger(namespace)
-#         try:
-#             logger.setLevel(log_level)
-#         except ValueError:
-#             logger.setLevel("WARNING")
-#             logger.warning(f"Configured log level `{log_level}` is incorrect. Defaulting to WARNING.")
+def logger_configured(logger):
+  return logger.hasHandlers() or logger.level != logging.NOTSET
 
-#         # Default settings
-#         console_handler = logging.StreamHandler()
-#         formatter = logging.Formatter("%(asctime)s - %(name)s - %(levelname)s - %(message)s")
-#         console_handler.setFormatter(formatter)
-#         logger.addHandler(console_handler)
+def initialize_logging():
+   global LOGGING_INITIALIZED
+   if LOGGING_INITIALIZED:
+     return
+   scopes = os.getenv("GOOGLE_SDK_PYTHON_LOGGING_SCOPE")
+   setup_logging(scopes)
+   LOGGING_INITIALIZED = True
 
+def parse_logging_scopes(scopes):
+  if not scopes:
+     return []
+  # TODO(<add-link>): check if the namespace is a valid namespace.
+  # TODO(<add-link>): parse a list of namespaces. Current flow expects a single string for now.
+  namespaces = [scopes]
+  return namespaces
 
-# NOTE: Option 2: Allow users to configure log systems.
-def setup_logging(namespace):
-    
-    # Instantiate a base logger unconditionally to avoid propogating logs to the root logger.
+def default_settings(logger):
+   if not logger_configured(logger):
+        console_handler = logging.StreamHandler()
+        logger.setLevel("DEBUG")
+        logger.propagate = False
+        formatter = StructuredLogFormatter()
+        console_handler.setFormatter(formatter)
+        logger.addHandler(console_handler)
+
+def setup_logging(scopes):
+    # disable log propagation at base logger level to the root logger only if a base logger is not already configured via code changes.
     base_logger = logging.getLogger("google")
-    base_logger.propagate = False
+    if not logger_configured(base_logger):
+        base_logger.propagate = False
     
-    # If a namespace is not provided, we don't need to do anything.
-    if not namespace:
-        return
+    # only returns valid logger scopes (namespaces)
+    # this list has at most one element.
+    loggers = parse_logging_scopes(scopes) 
 
-    # If the provided namespace does not start with "google", we don't need to do anything.
-    # We can update the regex to be more strict about the format of the namespace.
-    match = re.search(f"google", namespace)
-    if not match:
-        # TODO: raise an error? silently ignore?
-        return
-    
+    for namespace in loggers:
+      # This will either create a module level logger or get the reference of the base logger instantiated above.
+      logger = logging.getLogger(namespace)
 
-    # This will either create a module level logger or get the reference of the base logger instantiated above.
-    logger = logging.getLogger(namespace)
+      # Set default settings.
+      default_settings(logger)
 
-    # Set default settings.
-    if not logger.hasHandlers() and logger.level == logging.NOTSET:
-        console_handler = logging.StreamHandler()
-        logger.setLevel("DEBUG")
-        formatter = DefaultFormatter('%(asctime)s %(levelname)s %(name)s %(message)s')
-        # formatter = logging.Formatter("%(asctime)s - %(name)s - %(levelname)s - %(message)s")
-        console_handler.setFormatter(formatter)
-        logger.addHandler(console_handler)
+class StructuredLogFormatter(logging.Formatter):
+    def format(self, record):
+        log_obj = {
+            'timestamp': self.formatTime(record),
+            'severity': record.levelname,
+            'name': record.name,
+            'message': record.getMessage(),
+        }
+
+        for field_name in _recognized_logging_fields:
+            value = getattr(record, field_name, None)
+            if value is not None:
+                log_obj[field_name] = value
+        return json.dumps(log_obj)
\ No newline at end of file