2007-03-10 22:25:49 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Weather
There are many reasons global climate can change over periods of time.
1. Changes in solar output - that is, the sun gets brighter or dimmer, slightly
2. Changes in earth's orbital parameters - for example, the axis tilt changes slightly, altering the intensity of seasons, or the orbit becomes more or less elliptical
3. Continental drift - changing the locations of the continents affects how much or little sunlight they get, and because land heats differently from water, this can change climate. of course, this acts only over very long periods, like millions of years
4. Changes in atmospheric composition - more or less infrared absorbing gases (greenhouse gases) can change how much heat energy there is in the atmosphere, and therefore the climate
5. Changes in aerosol (or particle) concentrations. Think volcanoes or soot from huge fires, factories, etc.
and others. All these things act over different time scales, but virtually all of them are "natural". In the case of recent climate change (you're probably asking about global warming), the amount of CO2 in the atmosphere has increased very dramatically in the past couple hundred years, to a level it hasn't been in hundreds of thousands of years. Also, it has reached that level mroe quickly than has ever been seen in the geologic or ice core records.
This surely has an effect on the worlds climate. This is very different from how climate has changed in the past, and is strongly suggestive of human influence.
2007-03-14 08:02:43 · answer #1 · answered by yoericd 3 · 0⤊ 0⤋
There were climate changes in the past. Most of them were gradual, but i'm sure some of them weren't, like after a volcanic eruption, or comet impact. Nowadays though, the climate is doing things way out of the range of normal cuz of all of these different chemicals now in the atmosphere. Keep in mind that the climate we have now is very delicately balanced. There are a lot of variables, such as ocean temp, salt content, air temp, etc, that even when changed by themselves can change the whole picture kinda drastically.
2007-03-12 06:05:00 · answer #2 · answered by thefaz4371 2 · 0⤊ 0⤋
Many, many reasons humans have no controll over. NOT JUST global warming.
2007-03-11 07:47:11 · answer #3 · answered by Mr. m 1 · 0⤊ 0⤋
global warning
2007-03-10 22:28:29 · answer #4 · answered by hi 1 · 0⤊ 1⤋
sun flares
2007-03-10 22:27:59 · answer #5 · answered by q6656303 6 · 1⤊ 0⤋