I'm doing research for a project and I need to get opinions for both theories.

:)

Here you go. Look at this site. http://climate.nasa.gov/ It is a good start.

Also, you do not understand what a SCIENTIFIC theory is. You should use the word "idea" instead of theory if you are going to do a scientific research project. People may think you mean the scientific theory that nature causes global warming verses the scientific theory that humans cause global warming. There are no such SCIENTIFIC theories. This is a false idea that most people don't get.

A SCIENTIFIC theory is a set of mathematical equations based on observable data, years of hypothesis testing, and the century of knowledge accumulated in the scientific literature. Scientific theories are able to predict what happens for a given set of circumstances, Remember, these are mathematical equations. Gravity, light, atomic structure, evolution are all scientific theories, not just "ideas."

The idea that nature cause global warming or humans cause global warming are both part of the exact same scientific theory (set of mathematical equations). Scientists have determined a set of equations that influences when ice ages and warm spells will occur (look up the Milankovitch Cycles), they have equations that predict sun-spot cycles, and volcanic cycles. They have a set of equations that predicts how CO2 will change in the air as global temperature changes.Scientists can recreate past climates using these equations (hindcasting) an do so to study past ecosystems. Running the models ahead (forecasting), scientists know that we should not be warming but maybe cooling some as the next ice age approaches in 50,000 years or so. They cannot create the climate we now observe using only natural factors. The CO2 in the atmosphere is much greater than it should be if only natural sources we contributing.

CO2 can last more than a century in the air if it is not converted to a carbohydrate or other such substance. Here is where you need to think about things some. Remember in history class - the Industrial Revolution? That is when humans discovered a cheap fuel that allowed industry to grow - coal. You can dig it out of the ground and burn it. No more traveling miles to find enough wood for you factory. Dig up coal and use if - cheap and plentiful. This happened in the late 1800s. The natural sources of CO2 have not stopped, so using coal and other fossil fuels adds more CO2 to the air which the sinks need to absorb, or else the CO2 concentration will increase. This was thought of in the late 1800s also.

For the past ~150 years, the sinks of CO2 have not been able to keep up with emissions from the use of fossil fuel. CO2 has been accumulating in the air and concentrations increasing. Scientist can estimate how much CO2 will be put into the air from natural sources, and from fossil fuel use. If the scientist include CO2 from fossil fuel use in their scientific theory (mathematical equation), thy can recreate the current climate that they can directly observe. That is how scientist know the current warming is not natural. They can simulate the climate with only natural sources of CO2, and they can simulate the climate with natural AND human CO2 emissions. When you include natural and human emissions, we get current climate conditions.

Look at these sites too.

http://www.physicalgeography.net/fundame...

http://dels-old.nas.edu/dels/rpt_briefs/...

http://www.fs.fed.us/ccrc/climate-basics...

To recap - there is only one scientific theory (set of equations) that predicts both natural and human influences on climate. Burning fossil fuel is why CO2 concentration is accumulating in the air and it started ~150-200 years ago with the start of the industrial revolution, scientist cannot explain current climatic conditions using only natural factors.

Hope this helps.

The scientific theory is that humans are having a NET EFFECT on the current global warming. Therefore both natural and human factors are "causing" the current global warming.

It is important to realise human influences aren't "CAUSING" global warming (in strict terms), but SIGNIFICANTLY INFLUENCING it.

People are becoming aware of global warming simply because of recent warm weather patterns, plus increasing hurricane activity.

Clearly the Earth’s climate is changing. Here are the facts:

Average global temperatures have risen about 0.5°C in the past century.

Glaciers have melted and retreated dramatically.

Ecosystems around the world are being altered.

Here are some of the dire warnings:

The world has already entered a state of dangerous climate change. If the current pace of change continues, a catastrophic sea level rise of 13 feet could occur in this century.

Recent studies suggest climate change is rapidly leading to genetic impacts. Tiny shifts in average temperature are effecting genetic changes in living organisms.

Increases in hurricane intensity are due to humanity’s greenhouse gas emissions. Scientists calculate that two-thirds of the rise in sea temperatures is due to human emissions.

Siberia is melting. Vast tracts of Russian tundra, frozen for tens of thousands of years, are starting to thaw. Some experts say the process is taking place so fast, they can only attribute it to the effects of global warming.

The amount of Arctic sea ice is shrinking not only in the summer but in the winter as well, linked directly to global warming. In 2005 and 2006, the extent of winter ice was about 6% smaller than the average amount over the past 26 years. This is much faster than the previously observed long-term decrease of 1.5% to 2% per decade.

But, this is not new news. These changes started 18,000 years ago as the earth emerged from the Ice Age. Glaciers have alternately retreated and advanced as Earth has warmed and cooled, in cycles spanning hundreds, thousands, and millions of years.

Historical data from ocean sediments and ice cores indicate warm interglacial periods of 15,000 to 20,000 years separate each major ice age. We currently are in an interglacial period, and are due (some say overdue) for the next 100,000-year Ice Age.

There are many sources for the million-year history of the variations of temperature. Perhaps our human ego makes us think we are the primary cause and we can control nature and stop the changes. Over the past centuries, data indicates the Earth is indeed warming, but most of the warming (about 95%) is due to natural causes and beyond our control.

Global warming should continue, perhaps as high as medieval times. Then, there will be a sharp drop, to a small “ice age,” which will take about another 600 years. Perhaps at that time, human-generated global warming may even have a positive effect.

Because of the sound-bytes and short-attention span of trigger-happy media, we are completely unprepared for long-term issues. The media tests out several scary issues, seeing which will generate widespread “traction.” And then we run scared. We start making laws to prepare for the “cataclysmic changes” that are coming.

Over the next century, climate change will be the most severe problem we face. The questions remain: Can humans reduce their undeniable 5% contribution? Can we not only slow down global warming, but through technology actually reverse the trends?

I agree with Al Gore: We should “manage” the human effects on global warming through reduced emissions and other solutions he suggests. But, let’s not spend our national budget trying to stop or reverse a natural process.

There aren't two theories, there's the observational evidence that clearly shows humans are the cause, an opinion endorsed by 97% of climatologists as well as

American Association for the Advancement of Science

United States National Research Council

The Royal Societies of the United Kingdom, New Zealand, and Australia

American Chemical Society

American Institute of Physics

American Geophysical Union

European Geosciences Union

Geological Society of America

American Meteorological Society

American Astronomical Society

There is no scientific organization that thinks humans are not responsible for climate change. Groups that disagree with the scientific consensus include conservative think tanks such as the Heartland Institute, which used to spend its time doubting the negative health effects of tobacco smoke.

Here's the evidence:

We know that the planet is warming

We know that it isnt due to the sun (solar radiance has decreased over the past ~40 years)

We know that CO2 is a very effective greenhouse gas

We know that CO2 put out by humans due to its isotopic signature

We know that warming periods in the past have been preceded by higher levels of CO2 in the atmosphere.

It is BOTH of course, humans are warming the world with use of energy (all energy used usually turns to heat eventually) by heat islands, and land use, CO2 has a limited effect (maximum of 1 or 2 degrees without positive feedback and so far evidence shows there is little positive feedback and a lot of negative feedback) but all of humans warming is insignificant compared to natural cycles, Solar cycles, PDO, ENSO etc.,

We have a layer of atmosphere that prevents certain rays from the sun from hitting the earth and exterminating all life. It is called the Ozone layer. It is a relatively thin layer that is easily destroyed by chloroflourocarbons (spray can propellents) and carbon monoxide (CO). It is replenished by plantlife. The Ozone layer blocks the heat producing rays of the sun (study the Carrington Event of 1859).

The more trees we cut down, the less ability the Ozone layer has to be replenished. You have more Ozone over the tropical regions. There is one more thing though. Every time we launch a rocket into space, we destroy a lot of Ozone. Study about that.

So, cutting down trees prevents the replenishment of the Ozone to a certain degree, it thins the layer, and launching rockets into space destroys the Ozone layer. The sun does affect the heat we receive. Now, do you think there is a problem?

I remember back when I was a kid in the 80's. We were all going to die from "global cooling", and it was apparently the fault of humans and all the science supported it.

Now it's "global warming", it's all the fault of humans and apparently the science supports it.

What I am wondering is this. If whatever is happening is the fault of humans, then exactly why is Mars experiencing the same climate shifts that we are? Last time I checked there aren't any humans running around on Mars with SUV's.

Let the thumbs down from people who are afraid to ask questions begin.

Both

Felling trees,misusing water have endangered planet earth....................i think the huge population explosion has degraded all natural resources

Humans are a part of nature. We try our best to not leave an imprint but i would say as humans we damage the ozone more than help it. As for global warming...I see it as natural temperature change just on a larger scale of time... the planet went through ice ages and heat waves ... global warming is as natural as humans.

I'm doing research for a project and I need to get opinions for both theories.

:)

It's natural, caused by the Sun.

Watch these and see top climate scientists that are not going along with this scam explain it all.

The Great Global Warming Swindle