how/why has climate changed?

Question

how/why has climate changed?

Answer 1

I'll answer the How here:

There are a few major controls on the climate.

1)Albedo effect. This is the measurement of reflectivity of solar infrared energy. More albedo means more snow. Snow increases albedo. This is a positive feedback loop

2) Milankovich Cycles.

a)Eccentricity - these are changes in the elliptical orbit of the Earth

b)Axial Tilt - The tilt of our axis ranges from 21.5 to 24.5 degrees. It is currently at 23.5. A minimal tilt allows for colder climates.

c)Precession - This is the direction of Earth's tilt. It is to or away from the Sun.

3) Volcanic Activity - Sulfates, emitted in eruptions, act as nuclei for cloud condensation. More clouds result in a higher albedo.

4)Atmospheric Composition - Most important is carbon dioxide, a greenhouse gas. The current concentration is at 381ppm while historically it is shown at 105ppm less than this.



So, climate naturally varies. It is, on average, warmer than it is now. But in the Sturtian and Marinoan ice ages, scientists believe the entire Earth was glaciated and the oceans were capped by ice. Thus, there is a large range for global temperature.

The only part that is not considered natural is man's carbon dioxide emittance which forces a warming effect on the climate.

Interestingly, according to natural variability we SHOULD be expecting a cooling effect over the next 5,000 years.

Answer 2

what we call climate is....

actually just the redistribution of heat throughout the globe. The sun's rays provide the heat at the equator, and the wind and the ocean currents form to spread that heat north and south.



When the medium for the heat transference changes composition radically, as the atmosphere has(carbon), and as the ocean has (acidity), then the patterns by which it acts also change as the heat transference capacity changes.



Long term natural cycles obviously are at work as well.



Voici !! climate change!!

Answer 3

If the weather won't change, the climate won't change. The climate depends upon weather.

Answer 4

2 reasons



1) there is a natural cycle in the earths climate, and we are entering a warm part of that cycle



2) pollution put up by man has caused heat to become trapped in the atmosphere, and more heat to be allowed in due to thinning of the ozone layers at the poles

Answer 5

pay attention to the weather and how much it has changed for starters

Answer 6

because there are too many people on the planet using too many resources.