What is climate change?

Climate includes patterns of temperature, precipitation, humidity, wind and seasons. "Climate change" affects more than just a change in the weather, it refers to seasonal changes over a long period of time. These climate patterns play a fundamental role in shaping natural ecosystems, and the human economies and cultures that depend on them.
Because so many systems are tied to climate, a change in climate can affect many related aspects of where and how people, plants and animals live, such as food production, availability and use of water, and health risks.
For example, a change in the usual timing of rains or temperatures can affect when plants bloom and set fruit, when insects hatch or when streams are their fullest. This can affect historically synchronized pollination of crops, food for migrating birds, spawning of fish, water supplies for drinking and irrigation, forest health, and more.
Some short-term climate variation is normal, but longer-term trends now indicate a changing climate. A year or two of an extreme change in temperature or other condition doesn’t mean a climate change trend has been "erased.”

Worldwide, people are paying serious attention to climate change. In Washington state, climate change is already disrupting our environment, economy and communities. We can help slow it down, but we must take action now.

Greenhouse Effect

The greenhouse effect refers to circumstances where the short wavelengths of visible  light from the sun pass through a transparent  medium and are absorbed, but the longer wavelengths of the infrared  re-radiation from the heated objects  are unable to pass through that medium. The trapping of the long wavelength radiation leads to more heating and a higher resultant temperature. Besides the heating of an automobile by sunlight through the windshield and the namesake example of heating the greenhouse by sunlight passing through sealed, transparent windows, the greenhouse effect has been widely used to describe the trapping of excess heat by the rising concentration of carbon dioxide  in the atmosphere. The carbon dioxide strongly absorbs infrared and does not allow as much of it to escape into space.

A major part of the efficiency of the heating of an actual greenhouse is the trapping of the air so that the energy is not lost by convection . Keeping the hot air from escaping out the top is part of the practical "greenhouse effect", but it is common usage to refer to the infrared trapping as the "greenhouse effect" in atmospheric applications where the air trapping is not applicable.