How do we know that global warming isn't just the earth cycle?

Question

How do we know that it isn't ment to be like this, that it has nothing to do with fossil fuels.. what proof is there ?

Answer 1

Very simple

Humans exist and the weather changes.

Therefore it s definitely human caused and not natural

Answer 2

Some interesting points to note about global warming:-

In the Victorian period co2 emissions were at 100 times more than we produce now,yet they had normal cold winter weather.



Fossil fuel companies have been funding research into alternative fuel sources since the 1970's...they have to have some pay-off for all that money spent.

Most scientists and engineers agree that nuclear power is the only really viable cost effective energy source...funny how a lot of them are funded by the nuclear power companies.

Making wind turbine blades uses some of the most toxic chemicals on the planet.

To get the same power from wind turbines as you get from an average size steam turbine powerplant you would need 1000 turbines producing 1megawatt each continuously.

The same scientists that predicted the total loss of the ozone layer are the same ones which predicted global warming..the ozone layer is almost at it's "normal" level yet more of the harmful chemicals are being produced than in the 1980's.

Answer 3

I completely agree.  The "ice age" wasn't caused by humans was it?  I am sure that our every expanding population on Earth is not helping, but then we're all part of that cycle too.

Answer 4

Many governments have asked the same question.

They asked a group of people to review the published science and provide them with their conclusions.

<drumroll>

The Intergovernmental Panel on Climate Change.

"Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic (human) greenhouse gas concentrations."

We are very quickly heading towards 2 degrees of warming. that is not a nice day at the beach. that is people starving, dying and many animals and plants becoming extinct.

Please choose to do what you can. Your first step should be to buy compact fluorescent light bulbs... they will save you money and reduce your emissions.

:)

Answer 5

I think it is just a natural cycle as well.

The Earth has gone through many periods much colder and hotter than it is now.

Answer 6

The first bit of proof was the discovery of the greenhouse effect over 100 years ago by Joseph Fourier, who discovered as CO2 concentration increases, so does temperature. Then a Swedish bod call Arrhenius came along about 100 years ago and wondered what would happen to the temperature of the earth if the CO2 concentration would double. At this time scientist thought the atmosphere contained the same concentrations of gases and nature would keep them all in balance, so they largely ignored this question. For example, the thinking was that if CO2 concentrations increased then the oceans would keep on absorbing to maintain the same air concentration - we now know this not to be true.  

Next thing that happened was a guy called Milankovitch studied the earth’s orbital cycles and discovered changes in energy reaching the earth from the sun related to slight changes in the earth's orbit. However, these changes were slight and not considered enough to e.g. melt ice or make significant changes in climate.

Skip on a bit now to the 50/60s and a guy called Keeling first started measuring CO2 in Hawaii and other stations across the world. Measurements at remote sites provided the background concentrations away from influencing factors. From this curve we can see how global CO2 has been increasing exponentially since then, in line with production estimates from industrialized countries. The lack of any spike

during periods of volcanic activity is the simplest way to lay rest to that myth of volcanoes emitting more CO2 than humans. Little annual wiggles in the graph are due to plant life - since most land exists in the northern hemisphere there is more CO2 taken up by plants in the NH summer compared to winter. This is the natural balance of CO2 in the atmosphere.

Next comes the understanding of how ice ages occur. It was pretty obvious to scientists that there were huge ice sheets at one time, but how they came and went was a mystery. A large part is to do with how the ocean currents distribute heat from the tropics to the poles, and the interactions between CO2 in the atmosphere and that dissolved in seawater. The former is a bit irrelevant here but lookup "thermohaline circulation" to get and idea. For the latter you need to know that more CO2 can dissolve in seawater when the water is colder. It is here scientists began understand about the earth's feedback mechanisms and Milankovitch's work began to make sense....his calculated subtle changes in heat are enough to slightly cool or slightly warm the oceans depending on the current orbit. During slightly cooler times the seawater holds less CO2 and the atmospheric concentration goes up, because the atmospheric concentration goes up the greenhouse effect means the temperature goes up, because the temperature goes up the seawater warms some more and releases more CO2, causing the temperature to rise further. Suddenly we have a feedback mechanism, so the small shifts in solar orbit are amplified by the interplay between features on earth. Other examples of feedback for ice include: i) ice formation reflects sunlight making it cooler leading to more ice formation… ii) sea ice meting, the water underneath absorbs more sunlight, warms, and melts more ice… These types of mechanisms take thousands of years to slowly work and shift our climate between cold and warm periods.

Physical evidence for ice age cycling can be found independently in ice cores and ocean floor sediments, analysis of both of these from around the world give the same pattern of cool and warm periods for at least the last 400,000 years. This same pattern agrees with the cycles predicted by Milankovitch. Analysis of the air bubbles trapped in ice enabled past concentrations of CO2 to be measured and it was found that during cold periods it was around 180 parts per million and warm periods it was about 300 PPM. For natural cycles we would expect it to be within these limits. But in two hundred years since the industrial revolution it has risen to 377PPM. Suddenly Arrhenius's question about a temperature rise caused by doubling the concentration is relevant, turns out he was about right but understanding the consequences of the many feedbacks is where the urgent focus lies.

The understanding is here for how our climate has worked in the past, and we know that CO2 levels are related to temperature and were much lower during warm periods. The increase in CO2 concentration in the past 200 years is faster than the speed the Earth’s mechanisms have historically operated at.  The body of evidence has grown over many years with each generation of scientists filling in the pieces. Now we have a clear indication that we are in fact conducting an uncontrolled experiment on the earth and climate. The scientist's job is to report the facts, but I think because there is no easy alternative to oil, doing this becomes difficult against a tirade of misinformation. I think (and hope) the majority of the general public are finally aware enough willing to lobby governments and businesses, and change lifestyles to usefully limit our emissions.

Hope this helps and isn't too long!

Answer 7

Many scientists agree that the earth is just going through a cycle and that global warming is just a natural phenomanon.

But...

...is it a risk we all should take? What if they are wrong? Would it really kill anyone to cut down on their carbon footprint?

Answer 8

you should watch Earth:power of the planet.

Answer 9

People see what they chose to see, people make up facts where there are none, and are public education under the guidance of liberals are bound and determine to uneducate the youth and make them believers of nonsense.   This global warming is nothing but fear mongering and serves no useful purpose.  We all should take care of the enviroment and show respect for it however until people show respect for one another why would they care about anything else?

Answer 10

Some scientist are saying that

it's not global warming alone but

also the earths natural cycle

however they might have their motives

for downplaying global warming

eventually time will tell if some of it is the earths

natural cycle or not

I think most of the damage is by us

the proof is our cities themselves

it's always hotter when you are

in a big city

than the more environmentally friendly outskirts

Answer 11

You can`t stop the earth, you can`t stop people breeding, you just have to accept that it is what it is and get on with things the earth will sort it`s self out and maybe as a race "human" will survive but thats down to nature  not us and we don`t like it.

Answer 12

There is so much misinformation about GW, cycles and ozone layer. Fossil fuels are but a small part of the problem-less than 50%. But the problem is we are running out of oil. Think the Middle East would not pump as much as it can at $100 per barrel. We must have renewable energy. The cycle of earth and the sun are a great study in geology, but we have far more going on. Humans have cut down the rain forest, destroyed half the grasslands and are making new deserts faster than ever. Climate changes over 1000's of years, not like what we are seeing-except if the earth was hit, or volcanoes went off. But these are part of another cycle of magnetic forces.

Answer 13

It is the earths cycle b/c when the black plague hit it was cooler but then it got hotter and killed off the plague. So it has to be a cycle.

Answer 14

How do you know you're a person?  How do you know what that everyone that exists besides yourself is not just a manifestation of your own thoughts, and that you're the only person alive?  

A qoute from 311...  "The only thing I can prove is that there is no proof"

If you believe in any science, then I think it is fair to believe in this science...  After all, these are the experts saying it.  The so called "scientists" that do not agree with it are not really experts in that specific field.  They are usually chemists or geologists or something.  Not earth science or environmental science.  It makes a lot of logical since too.  Oh and global warming is a term that was originated due to the understanding of human influence on the environment.  The natural warming period of the earth is more accurately termed "deglaciation".

Answer 15

well im not a scientist but it can be a cycle or pollution caused by humans. either answer is correct for the moment

Answer 16

The earth does warm and cool on a natural cycle. The reason scientists like me know global warming is occuring and that humans are speading it up, is that we are seeing temperature increases unlike any time in Earths 4.6 billion year history. This is well documented by thousands of papers published in Nature, Science and other scientific journals as well as dozens of popular books.

Don't think global warming is a problem? Check out Under a Green Sky by Peter Ward. That will show you how wrong you are and what we are heading for if we don't do something to reduce greenhouse gass emissions now. We will cause the extinction of the human race.

Answer 17

There are many basic scientific facts which can only be explained if the current global warming is being caused by an increased greenhouse effect due to carbon dioxide accumulating in the atmosphere from humans burning fossil fuels.

For example, the planet is warming as much or more during the night than day.  If the warming were due to the Sun, the planet should warm a lot more during the day when the Sun has influence.  Greenhouse gases trap heat all the time, so they warm the planet regardless of time of day.  Another example is that the upper atmosphere is cooling because the greenhouse gases trap the heat in the lower atmosphere.  If warming were due to the Sun, it would be warming all layers of the atmosphere.

http://answers.yahoo.com/question/index;...

We know it's warming, and we've measured how much:

http://www.epa.gov/climatechange/science...

Scientists have a good idea how the Sun and the Earth's natural cycles and volcanoes and all those natural effects change the global climate, so they've gone back and checked to see if they could be responsible for the current global warming.  What they found is:

Over the past 30 years, all solar effects on the global climate have been in the direction of (slight) cooling, not warming.  This is during a very rapid period of global warming.

http://news.bbc.co.uk/2/hi/uk_news/62902...

http://www.pubs.royalsoc.ac.uk/media/pro...

A recent study concluded:

“the range of  [Northern Hemisphere]-temperature reconstructions and natural forcing histories…constrain the natural contribution to 20th century warming to be <0.2°C [less than one-third of the total warming].  Anthropogenic forcing must account for the difference between a small natural temperature signal and the observed warming in the late 20th century.”

http://www.pnas.org/cgi/content/full/104...

You can see this in the third graph here, where the dotted lines are just from natural causes, and the full lines are natural + human causes:

http://www.pnas.org/content/vol104/issue...

If that’s not enough to convince you the Sun isn’t responsible, consider the fact that no scientific study has ever attributed more than one-third of the warming over the past 30 years to the Sun, and most attribute just 0-10% to the Sun.

http://answers.yahoo.com/question/index;...

So the Sun certainly isn't a large factor in the current warming.  They've also looked at natural cycles, and found that we should be in the middle of a cooling period right now.

"An often-cited 1980 study by Imbrie and Imbrie determined that 'Ignoring anthropogenic and other possible sources of variation acting at frequencies higher than one cycle per 19,000 years, this model predicts that the long-term cooling trend which began some 6,000 years ago will continue for the next 23,000 years.'"

http://en.wikipedia.org/wiki/Milankovitc...

http://www.sciencemag.org/cgi/content/ab...

So it's definitely not the Earth's natural cycles.  They looked at volcanoes, and found that

a) volcanoes cause more global cooling than warming, because the particles they emit block sunlight

b) humans emit over 150 times more CO2 than volcanoes annually

http://volcano.und.edu/vwdocs/Gases/man....

So it's certainly not due to volcanoes.  Then they looked at human greenhouse gas emissions.  We know how much atmospheric CO2 concentrations have increased over the past 50 years:

http://en.wikipedia.org/wiki/Image:Mauna...

And we know from isotope ratios that this increase is due entirely to human emissions from burning fossil fuels.  We know how much of a greenhouse effect these gases like carbon dioxide have, and the increase we've seen is enough to have caused almost all of the warming we've seen over the past 30 years (about 80-90%).  You can see a model of the various factors over the past century here:

http://en.wikipedia.org/wiki/Image:Clima...

This is enough evidence to convince almost all climate scientists that humans are the primary cause of the current global warming.