From Astrobiology Magazine:
…Jim Green, NASA’s Planetary Science Division Director, said that one goal is to examine a variety of planetary bodies as a system, to see if there are trends or similarities. He also pointed out that from a planetary scientist’s perspective, climate change on our planet is not a new thing.
“Earth’s climate has done nothing but change,” Green said.
Green said that three Earth-observing satellites will be launched this year, and they will help us better understand how the climate is currently changing and the implications that has for our planet’s environment…
Global weather parameters such as temperature are not climate.
Climate: “the composite or generally prevailing weather conditions of a region, as temperature, air pressure, humidity, precipitation, sunshine, cloudiness, and winds, throughout the year, averaged over a series of years.”
It’s not good shorthand; it’s ignorance. A nonsensical marketing phrase invented to replace “global warming.” Global warming could indeed refer to something real, like mean earth temperature. “Earth’s climate” is nonsense.
You’re right that weather systems vary greatly across the planet. There’s also something to the idea that the climates interact and affect one another, so the term “climate” for the whole planet, while an oversimplification, is also a convenient and reasonable term. Same thing for the term “greenhouse effect”; it’s an oversimplification but it’s a good illustration to get people thinking. Granted, it’s also being used to get people to believe stupid stuff, but it’s still a reasonable shorthand.
At last, an honest perspective, as has been pointed out by our host for years.
‘“Earth’s climate has done nothing but change,” Green said.’
Earth doesn’t have a climate; earth has many climates. It seems our green genius doesn’t know what climate means.