EDITORIAL URBAN WARMING HEAT WAVE EXPOSED HOW POOR CITY PLANNING DAMAGES THE ENVIRONMENT.

YES, weather cycles cause temperatures to rise and fall over long periods of time. And yes, global warming surely has something to do with the heat wave that's suffocating greater Los Angeles. But there's also a cause that's more local, more direct and more our own doing -- urban warming.

Once upon a time, this region was mostly desert. Over the past half-century, that's changed dramatically. Freeways, strip malls, parking lots and golf courses now blanket our landscape, and the ecological effects are profound.

Heat reflects off the steel and concrete, and the dearth of trees means little relief. Lush golf courses absorb water all day, then let it off at night, giving the region blasts of humidity worthy of the East Coast.

Fifty years ago, the Canoga Park weather station recorded an average July temperature of 73.9 degrees. This July it's been 81.3 degrees.

But the oppressive heat and humidity need not be the price of progress. With more careful and environmentally friendly planning, L.A. could meet the needs of its people while also providing for a healthy, comfortable climate.

Unfortunately, smart planning has not existed in this city for the past 50 years. Rather than work from a coherent master plan, the city's broken political system lets individual council members approve developments willy-nilly, usually with little regard for anything except the developer's campaign donations.

This summer's unbearable heat is all the indication anyone should need that the practice must end.

It's time for L.A. leaders to come up with a sensible approach to planning that balances all the needs of L.A. -- economic as well as environmental. It's time for urban warming to be factored into all environmental impact reports. And it's time for the City Council fiefdoms to give way to a coherent system for approving developments.

If that means putting a moratorium on building until City Hall gets its act together, so be it. We have a city to protect -- and more heat waves to prevent.