With the amount of evidence that says global warming is man-made, how can anyone believe it isn't?

1) Yes. Faster warming during the nighttime indicates that this is a heat retention issue (consistent with AGW). If increased solar energy were the cause, you'd expect faster daytime warming (when the solar energy is hitting that side of the planet).

2) AGW predicts warming from the surface to the troposphere, and cooling in the upper portions (stratosphere) of the atmosphere. This is because greenhouse gases are keeping heat down and reducing infrared heating above. Increased solar irradiance would have the stratosphere and troposphere warming (the opposite of what we measure).

3) Even though we have only 30 years of direct measurements, we have very good proxy measurements (agreements using mutliple techniques) going back over a 1000 years. And while solar variation clearly can be seen affecting other climate changes, in the 20th century warming it's a minor factor overshadowed by anthropogenic forcings.

4) Shapeshi is incorrect The IPCC doesn't do studies on their own, they merely analyze the mountain of peer-reviewed literature done by many other research organizations around the world and provide a summary (in effect) of the consensus view. Many research organizations around the world have tried to determine the cause of the warming and a 90% confidence level that it's human caused has been reached by climate scientists from all over the world.

5) This is what the models predicted. More land mass in the northern hemisphere causes it to warm faster than the southern hemisphere (given the oceans heat absorption ability). And the northern latitudes are warming faster due to the decreasing ice albedo effect and the equatorial to pole wind patterns.

6) Though clearly not perfect, multiple independent models are indeed showing themselves to be fairly accurate.

Edit:

Eric C - No one says solar activity doesn't play a role in the history of climate change. But that doesn't mean it's responsible for all climate change past, present, and future. The Max Planck Society says it best: "solar activity affects the climate but plays only a minor role in the current global warming" (see link below)

I am beginning to feel as if reading and answering questions about global warming is futile. I wonder whether or not some of these questions are asked simply to see how stupid the responses will be. The huge number of posts who seem to really believe that global warming is not of any concern is astonishing. I do not know if humans are causing it or if it will happen again as it has in the past and I do not think it is worth arguing if we do not face the fact that we are doing more damage to Earth than it can probably handle and it is probably going to get much worse. Many emerging countries are just beginning to produce wastes. Toss your joint away and look around when you come back down.

I concur with earlier comments by Ken, JS & Dr. Blob. Your question has brought out attempts to deal with the question based on science from some of the other side, notably shapeshi, ecic, jim and tomcat. This is an encouraging sign. I think that the inclusion of the word believe in your question is the key. A better wording would be to accept the evidence rather than to believe. Belief has the connotation of accepting a dogma in the absence of direct evidence or proof.

Since the late 1970s, the amount of solar radiation the sun emits, during times of quiet sunspot activity, has increased by nearly .05 percent per decade, according to a NASA funded study.

"This trend is important because, if sustained over many decades, it could cause significant climate change," said Richard Willson, a researcher affiliated with NASA's Goddard Institute for Space Studies and Columbia University's Earth Institute, New York. He is the lead author of the study recently published in Geophysical Research Letters.

"Historical records of solar activity indicate that solar radiation has been increasing since the late 19th century. If a trend, comparable to the one found in this study, persisted throughout the 20th century, it would have provided a significant component of the global warming the Intergovernmental Panel on Climate Change reports to have occurred over the past 100 years," he said.

http://www.giss.nasa.gov/research/news/20030320/

Solar activity has not decreased in the past 30 years as you claim. The sun has been the most active that it has been for the last 10000 years. If you this is insignificant?

There are many studies that show a correlation between the sun and climate. A lot of them say the sun has played a significant role in warming the earth. But none of them is going to quantify something that is difficult to quantify. That would be irresponsible. Only scientists with political motives do such a thing.

For references to these studies see:

http://tinyurl.com/3yop6n

The studies that you support say that co2 alone without amplifications will cause a small temperature increase. It is the amplification that is going to cause catastrophic consequences. So if the solar scientists are correct and the sun has played a major role, the models will be off.

The troposphere is warming at a slower rate than ground temperatures. For more info see this NASA web site:

http://science.nasa.gov/newhome/headlines/essd06oc...

Most of the none tree ring temperature proxies show the existence of the LIA. The current warming is well within natural parameters of us coming out of an ice age. That is why Mann wanted to get rid of it.

As for climate models being accurate, they have been way off base in what they said the temperatures would be like today. Scroll down to the very bottom of this page and find out why only a computer illiterate believes in climate models.

http://tinyurl.com/3yop6n

1. How can anyone determine when more of the warming happens? Is this based on night time temperature records or something?

2. How does this support agw? Is it possible that the volume of gas added to the atmosphere causes warming at the surface by slightly increasing pressure?

3. solar output cant "decrease over the past 30 years", thats less than 3 solar cycles, in which the peaks and minimums happen every 5 years respectively, meaning there really isnt much correlation to be seen in 30 years. Ive also read articles from NASA stating the next maximum in 2011 will be quite strong. It isnt the luminosity that changes, its the uv and xray output, and we arent quite sure how that effects the atmosphere, there are theories, but nothing solid. Also, are you aware of the other solar cycles, the 88 year cycle, or the 200 year cycle? Does the IPCC address those? Did they study those, and try to determine their influence? See, the IPCC only studies things regarding man made changes. They arent interested in trying to find the natural causes.

4. The only "scientific studies" done to try to determine what is causing what amounts of warming is done by the IPCC. First of all, no one can try to determine what proportions of the warming are caused by what influences because we dont know what the natural influences are. The amount, and distribution of cloud cover is constantly changing, something that NO computer will be able to predict. Cloud cover can be effected by the solar cycles (theoretically).

5. Again, what does this do to support agw, exactly? If co2 is evenly distributed through-out the atmosphere, shouldnt warming happen more evenly? Could variations in the strength of the north atlantic current be the cause of this? If you ever watch how the weather systems move across the north atlantic, you'll notice how they get carried north of great britain quickly, could the current be traveling too far north because of melting ice? If so, there will be a tipping point in which there isnt enough ice to melt each year, in order to dilute the current enough to get it travel far enough north. Eventually, the current will sink farther south of where it does now, causing the arctic to cool dramatically.

Also, at higher latitudes, the sunlight is less focused, shouldnt there be less warmer there than at the equator?

6. How so? Have you gone to the future to check? Or are you trying to base this off of early predictions from 1988, in which 3 predictions were made, making it easier to be "right"?

Do you actually consider this evidence? Because it sounds similar to an evolution vs. creation arguement, in which people use the bible to try to support creation. Except in this case, the bible is the IPCC website....

1) No it is not, the planets temperature just plunged .75 C in thirty days, were was your CO2 to protect us?

2) The stratosphere shows no cooling, and in fact shows a warming tend over the last ten years.

3) No it has not, only when you include PMOD. ACRIM and other sources do not show a decline in solar activity until 2003.

4) I have showed you many times papers that can directly link TSI variations to at least 50% of the warming over the last century, without utilizing any feedback mechanisms.

5) Prove it, where is your data? The last time we crossed this path you could not provide it.

6) No they have not, were is the hotspot in the atmosphere that the radiative transfer theory demands, that should exists in the mid troposphere at the equator.

Not everyone is as educated on the supporting evidence, and the underlying science, as you are. In fact, very few are. They don't drive a Prius (as you do). They'd have to come to terms with being "wrong". Not everyone can handle that.

# 1, 2 and 5 may confirm that global warming is occuring as would be expected by carbon-based greenhouse gases, but that level of detail is probably above the technical knowledge of most of the people here (unless you explain it in far more detail in each question).

Then there the people who do know the technical underpinnings of those points, but choose to still deny (as reflected in the responses).

The response from "eric c" is fascinating, since he provides a link from NASA Goddard that opens the door to some potentially interesting influence from the sun. Too bad most skeptics here reject NASA Goddard (ROFLMAO)! So much for NASA Goddard Director Dr. James Hansen's "bias" and the "global conspiracy" (of scientists, liberals, socialists, communists, space aliens, or whatever people who believe in that sort of imaginary rubbish believe).

This is one of the most interesting questions (and set of answers) in weeks. I'll try to come back and respond in more detail (if it's not closed to answers first).

A lot of people regard the evidence for man made global warming rather as a sales prospectus for a product that they are being told they should buy. They know that the data is complex and are deeply suspicious because of this. The more people that say it is a scam reinforces scepticism (no smoke without fire).

Just to answer your first point, you do realize that the sun always hits the earth, don't you? When it's nighttime in America, it's daytime in China, and vice versa. So, the sun's always hitting the earth.

Global Warming advocates talk about scientific consensus, but immediately disregard any scientist who disagrees with the idea of man-made global warming. There was a letter written to the UN, signed by 100 scientist, of all whom do not believe that global warming is man-made. But no one listens to them. Anyone who disagrees with the global warming movement is obviously paid off by "Big Oil," or some evil corporation.

Bottom line, there is not scientific consensus on global warming.

You seem to be stuck on the same thing. Everyone agrees that CO2 levels have gone up. CO2 is a greenhouse gas. If greenhouse gases are increasing (as everyone agrees), due to natural warming and emissions by humans, then the result is that those increased concentrations of greenhouse gases are responsible for moderating the coldest temperatures. That in no way suggests that humans are responsible for significant warming, only that we increased greenhouse gases from the emissions of CO2 as the result of burning fossil fuels. I think a conservative estimate of human emission is a 100 parts per million by volume of the almost 400 ppmV in the atmosphere. This explains items 1,2 &5. Regarding the solar output, you have to take into account the theories of magnetic disturbance and cloud formation.

You also demand an explanation when the fact of the matter is our knowledge is limited. You can manufacture computer models to suggest whatever you want. Why anyone would give them much credibility is beyond me but that is all the alarmist have to rely on.

Remember what you are talking about. It is a degree. The natural variation is far higher than human influence and huamn influence is impossible to quantify. Trying to blame humans for something so miniscule is rediculous IMO