Greenhouse effect?

Question

I understand the whole global warming phenomenon. I understand the factors that leading scientists identify as being the cause. However, I think that it is arrogant for humans to believe that we are really impacting the world that much.
Here is the problem: Scientists claim that the earth is over 4.5 billion years old. Recorded history only spans back 5000 - 5500 years. Geological temperature record identifies various "ice" and "desert" ages over the last 200 million years. Scientists have purported cycles of higher and lower temperatures dating back 2000-3000 million years.
Question: How can we prove that we are "responsible" for global warming? How do we know that this is not just a regular cycle of the earth that we happen to be here to record? After all, scientists are just presenting various hypotheses. So why do we believe them?

Answer 1

I do not believe statements that the Earth is warmer now. But I DO believe statements that the carbon dioxide levels in the atmosphere are higher now than at any time in the last half million years.

The reason I don't believe the Earth is warmer is that Earth does not have one temperature. It has hot summers and cold winters. It has hot tropics and cold poles. I have felt the temperature drop by 20 degrees in one hour as a storm approached. Any single temperature of the Earth must be some kind of average, and a very hard to computer average. There are as many different average temperatures as there are people reporting them. I don't trust them.

The reason I do believe CO2 levels are higher is that CO2 concentrations are the same world wide due to efficient mixing in the atmosphere. And that concentration is easily measured today. Current air samples give current values and air bubbles trapped in glaciers give past concentrations. Ice cores from thick polar glaciers show layering that can be seen, just like tree rings, each layer being one winter of snowfall. Simply drill out a deep ice core, count the layers, use modern lab equipment to measure the CO2 concentration in air bubbles at that layer and every scientists in the world agrees with the result.

Bottom line is, CO2 is a known green house gas, it is reasonable to conclude that more green house gas will trap more solar heat in the atmosphere so that at some point, if we keep adding more and more CO2 to the air, the planet will warm up. But how soon and by how much is up for debate. I see no evidence that any significant unnatural warming has taken place yet. Some glaciers are shrinking but others are growing. Some ice on the coast of Antarctica has melted, but ice is still getting thicker at the south pole. And so on.

Answer 2

Why is it arrogant to believe humans are impacting the world that much?

Since the beginning of the industrial era in the early 1900's... a mere 100 years ago...

Scientists conclusively proved that our activities were severely affecting the ozone layer, no one disputed it.

Science harnessed the power of that atom and the nuclear age began. Scientists went on to show that above ground nuclear testing has been contributing to world-wide fallout to the point that above ground testing was banned.

Humankind has accelerated the extinction of Earth's natural biodiversity. No one disputes it.

Humans have used and abused so much Persistent Organic Pollutants (toxic chemicals such as DDT, dioxin, polybrominated ethers, etc) and released so much mercury into the environment that even the Arctic wildlife has levels of POPs that are considered to be unsafe for humans. Native Arctic humans didn't put the POPs there, modern civilization did.

Humans are producing so much material waste that there is no place to put it without some community group complaining about it so we started offloading garbage on barges.

Humans have altered and changed our environments so much in the past 100 years alone, recultivating landscape, altering ecosystems, redirecting rivers, contributing to desertification.

It's just as arrogant and irresponsible to say that humans AREN'T affecting the world at all. But really, here's the thing about global warming... right now we are at the stage where we are begin given a warning, call it alarmism if you want to.

But do you really want to wait 50 more years when it's too late to do something about it?

Every scientist in the world now is talking about unprecedented glacial melting. The total Arctic ice has reduced in size by 10% since 1960. Greenland is losing ice off glaciers that haven't melted in thousands of years. Scientists that once laughed global warming off, stopped laughing when a major glacier in Antarctica suddenly collapsed and melted into the ocean. Why? Because the scientists that didn't believe in the global warming phenomena believed that as the Arctic got warmer, the Antarctic would correspondingly get cooler and compensate. It didn't. Now Antarctic glaciers are melting too.


If humans ARE contributing to the global warming, why wouldn't you want to try to stop it?

If all we are doing is just causing a small burp in Earth's natural cycles.... then still, what is the harm in trying to live a greener lifestyle?

Do you really want to wait till the evidence is undeniable? Because this is very much a matter of trying to put out blazing inferno with a dixie cup full of water.

EDIT: Here's a link to NASA's Arctic website. Can watch an animated gif of polar ice cap shrinkage and other photos.

http://www.nasa.gov/vision/earth/environment/Arctic_Warming_ESU.html

Answer 3

I don't believe that scientists claim that we are the cause of global warming. Certainly not of the melting of the ice caps.
The ice caps have been receding for some time now. It's a matter of how much faster they melt now.

The issue is more that scientists have come to understand the factors that correlate to global warming.

We may not be the whole cause, but we are certainly a contributing factor. IOW, yes global warming may happen anyway. How "quickly" we start seeing negative attributes can be directly attributable to human factors.

To think that we have no affect what-so-ever to our environment would be blind ignorance. The degree that we contribute to the change of the earths environment in comparison to naturally occuring changes is more at question.

It doesn't take a genius to understand that we contribute to some degree.

Likewise, how do we know for sure that a million years ago there was not another advanced human species that also caused atmospheric changes? What, you think we should have dug up a 1 million year old car by now?

Answer 4

My thoughts are that there are a combination of factors at work. Yes the Earth goes through various climactic cycles and the current weather pattern changes we're seeing might very well be a part of a natural change in the cycle.

However we cannot ignore that humans have made some impact to the atmosphere. We did contribute to the hole in the ozone layer - that cannot be denied. We also pump tons of chemicals in to the atmosphere that were never pumped into it any other time in Earth history.

You're right that scientists are only hypothesizing and we don't really know how much we're effecting the natural cycle of the Earth's climate - but these things are rarely black and white. I bet we are going through a natural climactic shift, but the shift is not going the way they usually do because of the impact we have had on the Earth. I think both factors must be considered.

Answer 5

I hate it when humans are so stupid. Yes, there has been times when the earth was a desert or covered in ice. The earth has changed and does change. However, the fastest change ever identified (in the last 5000 years) of ice melting has occurred in the last 50 years. The main cause is air pollutants, aka industrial age, aka us. I think it is ignorant to think that humans (there is over a billion of us) are not impacting the earth. Look at Google earth website, and do a scan of the earth, you will see how urbanized, clear cut, or 'changed' the earth is by human hands!

Answer 6

Scientist are able to measure the increase of the gasses in the atmosphere, and can use this data to calculate the amount of heat that is being retained now, compared to the amount retained before the gasses were present. Using past historical references and modern computer programs, the effect of a continuation of the buildup of these gasses can be predicted. Also, earth cycles do not happen at the rate this one is without an outside influence ( I am talking about meteors, not E.T.). As for the arrogant comment, it is more arrogant for people to just pass the facts off simply because they want to drive their SUV a few blocks.

Answer 7

They have identified the means, substances which can lead to global warming in various models. And they have identified the outcome, not just warming but extremes in weather such as increased hurricane forces, changes in climate zones, and altered rainfall patterns.

But like you say, just because we might know how it works doesn't mean that there aren't other forces at work. Volcanic ash also affects worldwide temperatures, as does the population sizes of various planktons (which can be influenced by seafloor volcanic activity). 100% certainty is not available in science; we can only have overwhelming support for a theory.

Answer 8

EP, enable me be sure from the outset that i know little or no in this concern, so, in spite of our disagreements interior the previous, I’m *no longer* contradicting you right here – in basic terms attempting to understand. I’m additionally perplexed via the section you highlighted. If the planet won 240 W/m^2 of power from the sunlight, how can the ambience “radiate 240 W/m^2 into area, [and] additionally radiate 240 W/m^2 lower back in the direction of the floor”? The regulation of conservation of power states that power can't be created or destroyed, yet, in accordance on your description, the ambience is receiving 240 W/m^2, yet reradiating a entire of 480 W/m^2. earlier each and every thing look this seems to be impossible. What am I lacking that makes this artwork? :::EDIT::: Oh, so the “radiate 240 W/m^2 into area, [and] additionally radiate 240 W/m^2 lower back in the direction of the floor” quote is the placement *after* equilibrium is reached? So it’s the area on the tip factor, no longer the beginning factor?

Answer 9

natural cycle,sure. lightning sparked forest fires create co2 + pollution. earth heats & blows volcano which dims the atmosphere with ash & blocks sun. hurricane heats up from ocean & spreads the water + removes insulating layer of co2 from surface.coooooool.
research: global warming & global dimming. i saw a pbs show once.
humans burn 80 million barrels {44gal/barrell} of oil /day. add to that gas,coal,wood,gunpowder...
the co2 + methane +any sinking gas like the new freons blanket the earth for heat retention. the atmospheric particle pollution blocks the sun's rays from delivering heat.
clean enrgy via fossil fuels 'i think' would be disastrous.
limited resourses deserve conservation. co2 can saturate the atmosphere.
research: global warming, dimming, & pan evaporation rate.personally the radcal weather makes me freak & i wonder why motorsports arent all illegal.

Answer 10

Why don't you believe them what is your problem the greenhouse is no longer a theory it has been preuven it it is happening the and far as the temperatrues going up and down that is ture but normally temps have never been this high in any previous stage in earth's history.