What caused climate change before humans inhabited the earth?

Answer 1

its a misconception that humans cause climate change. Apparently down to our CO2 emissions. Volcanoes kick out more CO2 in a year than all the cars, factories and power stations put together. In fact humans only contribute a measly 3% of the earths CO2. The largest contribributor being the sea, which actually omits more the warmer it gets. If climate change is really down to CO2 how did the earth ever cool down when a warming meant a natural increase in CO2???

Answer 2

Are you inferring that humans control climate change?
Because before humans or while humans are inhabiting the Earth, the climate change is caused by the tilting of our planet on its axis.
If you want to know about changing weather that can also be affected by the tilting on our axis, as well as, other more specific changes in the atmosphere. For example: Clouds produce rain.

Answer 3

Both Earth and the Sun go through a series of cycles, there are many of them varying from 11 years to 430,000 years - the cycles Earth goes through are collectively known as Milankovitch Cycles and the effects caused by the cycles of the Sun are called Solar Variation.

The world has always either warmed up or cooled down, historically these changes have been driven by the various cycles and have occurred over periods of thousands and millions of years.

The interaction between the cycles is complicated, sometimes two cycles cancel each other out, sometimes they can compound each other.

Because the cycles are regular we can produce computer programs that show what has happened in the past and what will happen in the future. In this respect it's like predicting when the next high tide will be or the next solar eclipse.

These same cycles have been affecting the climate all the time that humans have been on Earth - they still are. The difference now is that human activities are now a driver of climate change and changes are happening many times faster than can be attributed to natural cycles.

Answer 4

Hello,

(ANS) The earth is calculated by cosmologists & astrophysicist to have been formed approximately 60-70 billions ago. The earth started out a a purely molten sphere of matter. Since the earth cooled and later came to form a solid hard surfaced planet its climate has ALWAYS under gone continuing changes.

These changes have been influenced by many factors amongst which are: Plate tectonics (movement of the earths land masses over geological time, the wobble of the earths axis, the earths orbit around the sun which varies over many hundreds and thousands of years, volcanic eruptions, and so forth.

The earth has been through numerous ice ages and desertification process's over its long history, all of this many times before humanoids arrived.

**To some degree, some of the current climatic changes we are starting to observe are without any doubt driven by the planet itself and would have taken place anyway without humans.

Its my belief that, human beings have only increased the rate of the climatic change by pollution caused directly from human activity. The increase in carbon dioxide has only jumped in the last 150 years since the industrial revolution & the invention of the internal combustion engine.

**Cars and aircraft are responsible for the most pollution, aviation itself may be responsible for only a few % of the problem but the pollution from aircraft is x3 or x4 more damaging because it is ejected into the upper atmosphere hence going the most damage most quickly and directly.

Ivan

Answer 5

This a a good, and very profound, question. Lots of implications. Glad you asked it.

I am going to set some ideas up, and then cut to the question; please bear with me.

A lot of our Universe as we know it resembles a very large, complex machine, set in motion, and doing what it does without further attention. Works on the laws of physics and chemistry. If we had enough information on everything, and a big enough computer, we could simulate and know what would be the state at any time past and future.

We don't, so we do a lot of guessing!

Life introduces additional variables to the grandure of the mechanical system. Makes the computations indefinitely more complex. "Free Will" adds another factor of great complexity, beyond calculation.

I do disagree with those who say we have it all calculated out. So far we have calculated guesses with the last uncertainty factors I saw giving a warming effect of from 2 to 10 degrees, roughly, over 400% variance. And the input data is suspect due to the non-random distribution of samples, being heavily weighted to be in urban areas. And the last few curves I saw touted used smoothing factors in the computer program to remove the "inconvenient" MWP and LIA and the 11-year solar cycle;

Any Ham radio operator in the higher bands knows what drastic changes the sun does to the upper atmosphere during sunspot cycles. I used to look forward to the larger spots actually ionizing (breaking up the electron orbits and ejecting free electrons) down into the "D" layer of the atmosphere, because the then more reflective atmosphere sent my radio signals much farther.

But that energy dissipates into the atmosphere, and most likely reappears as the heat given off in the recombination of the atoms.

I have noted in reading that there are many assumptions made, and small changes can really alter the output, and the computer programmers alter the equations until it shows the desired results. Such as effect feedback parameters, which seem to be assumed, not yet measured.

And remember, computers can make millions of "mistakes" a second, given prejudiced data to work on. They only do as they are told by the programmers and the data feeders.

Before humans, it was 100% "natural", Sun's energy output, position of the poles, various natural events as volcanoes, impacts by asteroids, Sunspots, perhaps cosmic radiations of various types, and when life appeared, the effects of being alive, and dying.

The vast fields of plants we now call coal had a big effect on the CO2 levels in living, taking in carbon as CO2, and releasing it in death and decay.

Mankind, acting with intelligence (maybe), and avarice (definitely) has altered the equations. BUT WE DO NOT KNOW HOW! We can only guess, and that can be dangerous.

Computers are not always right, a thing most people do not consider. The GIGO principle applies. and with something as complex as the earth system, we frankly have to just guesstimate, and from limited and often defective data.

Means someone with an agenda can change the data in, and the weights given, and come up with a different scenario.

I think the jury is still out, frankly, since the programs I have seen have to smooth out solar effects, and presume the MWP and the LIA and other known climate variations do not exist or do not affect the future, to get calculations that agree with the agenda that mankind must be reined in before we ruin the world.

But this is not the question. The answer is "nature" did...it all was "natural", no matter how much got wiped out every so often. Even the mighty dinosaurs were brought low in an instant of time, apparently, by a natural cause and effect.

But the presupposition of the question is that man, somehow, is the one causing the changes now, and the implication is they are un-natural and therefore "bad".

This implies that in turn that man is NOT a part of nature, which does not seem right. I believe I can as easily say that ALL climate changes are "natural" because man is a part of nature, just given intelligence, and using it (mis-using it?) to cause changes.

And I personally see them as being more likely to be beneficial than detrimental, provided Man does not dig his heels in and try to deflect the normal course of nature, trying to have his cake and eat it to. And provided that greedy and powerful men do not step in to seize or destroy the benefits and try to control fellow men for their personal interests. Ala 1984 and other similar projections.

I think Man has the options of going with Nature's flow, making lifestyle modifications to fit in with the apparent natural warming, including man's contributions if any, and developing, or to fight tooth and claw and get knocked flat, losing our freedoms to those who want power and control, and kinda live miserable little existences.

But either course would be "natural" and I don't think the Earth cares a whole lot!! Nature will do its thing with or without man.

Not quite what the simple question asked, but hope it is beneficial and can cause some thinking to go on.

Answer 6

There have been natural climate changes before, mostly due to the Sun. But the data clearly shows that, starting about 40 years ago, man's contribution overwhelmed the natural forces that controlled climate before.

This is a nice picture, includes the effect of the Sun and volcanoes, and there are many more scientific studies showing the same thing.

http://www.globalwarmingart.com/wiki/Image:Climate_Change_Attribution.png

None of the other explanations works nearly as well. The scientific equations don't work for them. The numbers come out wrong. Most arguments about it are answered here:

http://environment.newscientist.com/channel/earth/dn11462

Good general information on global warming. with data and pictures:

http://profend.com/global-warming/

Answer 7

Humans have been on the earth since the sixth day of Creation. Major climate changes were caused by Noah's Flood.

Answer 8

There are a variety of factors that influence or cause changes in climate. That, in fact, is why it took so long (about 20 years) for scientists to be entirely sure that the current global warming is due to human activities. You've probably heard of a number of these things--especially since many are possibilities schientists examined and ruled out before determining that CO2 emissions from burning fossil fuels is the culprit. Some of these factors include changes in solar radiation, variations involcanic gas emissions, and changes in ocean currents.

Answer 9

Lots of natural processes caused climate change. But human activities can also cause it. What's so surprising about that?

When you put natural warming trends together with human activity, you can get extreme climate change too. What's so surprising about that?

Answer 10

There were many factors, and precisely how they came together to produce the changes is not understood, which is why the notion that we can determine that X amount of CO2 is causing Y amount of warming is ridiculous.

Trever: "The world has always either warmed up or cooled down, historically these changes have been driven by the various cycles and have occurred over periods of thousands and millions of years..." NO - many such changes have occurred over periods of a few HUNDRED years during which CO2 levels were LOWER THAN TODAY.