why has the climate changed over time?

Question

plz explain in a paragraph

Answer 1

There are really only three major answers listed and discussed below.

The answers are:
*we don't know,
*natural occurrences, and
*plate tectonics,

Plate tectonics is the movement of large parts of the earth's upper surface (also called continental drift, see ref 1). When the plates move, they can interrupt ocean currents and affect weather and climate.

About 3 to 5 million years ago plate tectonic movement closed up the gap between continents where Panama is today.

The subsequent changes in worldwide ocean currents caused *massive* changes in worldwide weather and thus climate. The recent cycles of warm and cool may have come from those changes.

(some people credit this change with the changes in African climate and vegetation that caused a primate to descend from the disappearing forests and walk on two legs)

Natural occurrences may be unexplained or included in solar cycle explanations (see Milankovitch, ref2).

Regardless of cause, *anyone* can understand the weakness of the argument by looking at scientific data of paleoclimatology but I doubt that those already convinced will be able to change their religious beliefs.

One of the best examples is based on the Vostok ice core records, as follows:

*look at the graph of temperature and CO2 (ignore dust) in the third Wiki reference
*notice the periodic increases in temperature and CO2 over the last 400,000 years
*ask where the SUVs and coal-fired plants were in the previous *four* global warming events

Another good example based on the Vostok data is to ask *why* CO2 concentrations lag behind the temperature increases by 800 years?? (ref4)
(One generally accepted answer is that *after* the oceans heat up they release dissolved CO2).

Finally, why are the other planets in our solar system all warming at the same time (ref5)?

Answer 2

The climate changes through natural occurrences such as ice ages, and warming periods. The temperature is always in stride with CO2, so when CO2 is high the temp is high, when it's low the temp is low. Scientists can prove this over the last 650,000 years. Since the industrial revolution, which started in the mid 1800's until now, we have increased the amount of CO2 to a level that it has probably never been, and in short time. At the current rate we are doing this our planet will be drastically different in 2050 than it has ever been before, let's hope we get our act together soon. Hope this helps.

Answer 3

xxpat 1 -

CO2 acts TWO WAYS. It causes warming (greenhouse effect) and it is released from ocean waters as they warm and can't hold as much. Basic science.

Past warmings were caused naturally and CO2 only increased later when the ocean warmed.

This time CO2 is going up side by side with temperature.

It's one of many scientific proofs that this warming is caused mostly by us, burning fossil fuels. More here:

http://www.realclimate.org/index.php?p=13

All the planets are not warming, just a few. So it's not the Sun. The NASA scientists who actually measured Mars temperature said it was probably due to giant dust storms, long observed on Mars.

http://www.nasa.gov/centers/ames/research/2007/marswarming.html

Also see:

http://solar-center.stanford.edu/sun-on-earth/FAQ2.html

Answer 4

Two paragraphs...

HISTORICALLY
Both the Sun and Earth go through a series of natural cycles. The Earth's cycles affect the way the planet moves in space - it 'wobbles', these movements were documented by Mutin Milankovitch and are given the term Milankovitch Cycles. The sun also goes through a series of cycles which affect the amount of heat energy we receive, these cycles are known as Solar Variation. These cycles interact and over long periods of time can trigger periods of warming or cooling.

RECENTLY
Global warming is governed by levels of atmospheric greenhouse gases and since the onset of the Industrial Revolution in the mid 19th Century levels have risen dramatically and this has exacerbated the greenhouse effect leading in turn to global warming and climate change.