A question for climate change skeptics and deniers?

I'm not a climate change denier but I think I can answer your question regardless. They would probably say that although human emitted greenhouse gases do retain heat, their contribution to the total is minimal. They'll claim that natural variations in solar activity or volcano emitted gases cause the change in the composition of the atmosphere.

Anyway, observing rising temperatures etc. is not sufficient proof for human responsibility. You need lots of data and complicated models to determine that. But, with all the data that has been collected over the past few decades it has become very likely that humans are the principal cause of the problem.

Aw Trevor, you can do better than that!

All your statements are true. The problem is your reasoning is terribly simplistic. Yes, increasing CO2 will increase the amount of solar radiation (heat) trapped by the atmosphere. The glaring omission here is that there are many, many other factors which influence terrestrial temperatures. One only needs to look at an historical graph of temperature and CO2 levels. In previous warm periods, CO2 levels lagged temperature increases. So the temperature increased and a CO2 increase followed. You know very well why- more CO2 left the ocean due to heating, permafrost melted, etc. Then temperature slowly drifted down while CO2 followed. Apparently, there are certain natural feedback mechanisms which keep the temperature stable within a narrow range.

Historically, temp goes up first, CO2 levels follow. And temperature didn't spiral out of control. But your statements are still correct as written.

i like to quote a meteorologist colleague of mine on this topic. The human carbon emissions contribution to global temperature lies in the second place of decimals of a degree centigrade, they may reinforce natural warming, or mitigate natural cooling by some fraction of a degree, but they are not the principle driving factor.

Given that it is the AGW lobby who are demanding huge sums of money and political power on the back of their hypothesis, it is their obligation to prove their case, not the other way around. Simply declaring the case proved and refusing to acknowledge any of the skeptic's scientific criticisms only strengthens support for the skeptics in the general population

I believe our point, skeptics that is and me in particular, accept that mankind contributes to the global climate. What we question is the amount of influence humans have as compared to nature.

Those like myself do accept that man contributes to the total GHG in the atmosphere. However I believe that nature almost completely eclipses the human contribution.

I also believe that the SUN is the primary driver of the earth's global climate. I know and understand that solar irradiance has only varied by a couple of percentage points since we've been able to measure it. However, the sun has many more mechanisms that effect the earths climate than irradiance.

1. Solar wind

2. Interplanetary Magnetic Field

3. Shifts in the IR content of Irradiance

etc

This debate has been done already.

Next please.

Also, more research, and not just about carbon dioxide emissions being the ONLY culprit of alleged man-induced GW.

It's like a damages case:

The globe (the one filing for damages) is allegedly warming extraordinarily, and we are looking for suspects. And it's like the prosecution (alarmists) are insisting on convicting humans on being the earth's sole cause of distress hence the damages claim, when it should also consider other factors, because it is NOT FAIR to limit accusations and investigate just one possible suspect.

One should also consider of the earth is just a hypochondriac, insisting it is sick (the alarmists' usual analogy) when in fact is happening to it is actually normal and infact healthy since it is the norm.

Hi Trevor...

An interesting list of questions...

• Greenhouse gases occur naturally// yes

• Humans emit greenhouse gases//yes

• Greenhouse gases from both natural and human sources are found in the atmosphere//yes

• Greenhouse gases have the ability to retain heat// yes

• Natural greenhouse gases create a habitable climate on Earth by retaining heat// yes

• Human emitted greenhouse gases retain heat// yes... BUT HOW LITTLE!

You expect us to assume that we’re discussing anthropogenic GHG’s, but omit to mention that the most significant greenhouse gas is water vapour... principally sourced from the oceans. You well know that CO2 and CH4 are minor components of the greenhouse effect in comparison to this, and that the anthropogenic portion of these in the atmosphere is relatively tiny.

“If you don’t accept that human emissions of greenhouse gases can contribute to global warming, can you please explain why it is that natural greenhouse gases can but human ones can’t.”

Oh Please! UV is indiscriminate. It doesn’t care what CO2 it is meeting. But that still doesn’t change the question ‘how much’ impact does anthropogenic CO2 have on our climate?

“On the other hand, if you don’t accept that natural greenhouse gases can cause warming, please provide an explanation as to how Earth has a habitable climate given it’s distance from the Sun.”

Indeed ,I do believe that natural greenhouse gasses can cause warming. What’s your point?

Your opening line is of concern... “A lot of evidence is put forward that ‘proves’ humans are causing climate change. We have for example, the rising sea-levels...”

Would you like to provide the evidence that ‘proves’ that humans have caused sea level rise please?

Since there are "millions of scientists in the world working in fields that relate to global warming and climate change" and since you are "a climate scientist myself so please avoid silly answers such as ‘they’re afraid to speak up’ or ‘their work gets discarded’, the reality is quite the opposite." you must have some examples to support your view of reality. Who are these climate scientist that have spoken up who's work doesn't invoke a desire to discard there work or discredit them? strpenta - No, we don't "think" warmons are hypocrites, they are. Trevor himself thinks 90% of the earths population believes there is a problem with their lifestyles. 90% is enough to make the changes he believes are necessary to save the planet. Either he's ignorant about the 90% or the 90% are hypocrites.

Actually, you have no flaws in the statements that you have made. The problem with people like you, is that you think that man is driving this round of climate change and most of the AGW supporters have had to rewrite history to make their point.

Most of the skeptical experts in climate science accept the notion that co2 is a greenhouse gas, and it should cause some warming. But as Richard Lindzen puts it, it is not a question of if humans contribute to warming, but how much, is it a cause for alarm.

Melting ice caps is not proof of AGW. To say so implies that natural warming will not cause ice caps to melt. Black carbon can also cause ice caps to melt.

Sea levels have been rising since the last ice age, there has been no alarming rise in sea level over the past 50 years.

Incidence of droughts have not increased (Sheffield et al)

Dana. It is well known that most people who support cap and trade believe "it is the right thing to do", even if global warming is not real. Since the 70s these people have been campaigning for an energy bill similar to cap and trade and were unsuccessful. With the global warming scare they are making progress. Now you are asking us to believe that even if global warming is not true, they will admit that. Sorry, but I know that most leftists consider themselves to be intellectual superiors, and the masses stupid ignorant people. Even though I do think there are merits to reducing energy consumption, I cannot support a bill that misrepresents itself. It goes against basic democratic principles. There is no such thing as an honest lie.

As for there is no economic basis for apposing cap and trade, if you raise the cost of production for American goods you have increased the price difference between American goods and Chinese goods, leading more people to buy Chinese goods, putting Americans out of business and work and transferring co2 emissions to China were they do not have to conform to reducing emissions. Cap and Trade makes no sense from a global warming standpoint if China and India do not come on board. This is basic economics. That fact that you support it means that you are doing it for other reasons.

Edit: Paying for carbon sinks, sequestering co2, will do nothing to reduce black carbon. You also said that there is no economic basis for apposing cap and trade. I gave you one. Do you really think that reducing energy consumption has no political implications? Wow! Patrick Moore, cofounder of Greenpeace left the organization because people were cloaking a left wing agenda under environmentalism. Lawrence Solomon, member of the environmentalism movement Energy Probe, has said that many people have said to him that they do not care if global warming is real or not as long as energy reduction is implemented.

Most deniers don't deny that CO2 is a greenhouse gas and that human CO2 emissions are contributing somewhat to global warming. Although some do get quite belligerent and claim humans aren't contributing to global warming whatsoever - these are the real nutjobs, completely impossible to reason with.

Then there are the deniers who deny that we can quantify the amount of warming caused by the anthropogenic CO2. This is a denial of physics, which is easy to do, because the physics is pretty complicated. It gets into things like radiative forcings which most people don't understand, which makes it easy for them to argue that *nobody* understands it.

The denier answer to these questions is always the same. We don't know, you're arrogant to think we know, all you damn alarmists exaggerate what we know, etc. The only thing we know is that humans aren't causing global warming because that would mean regulating CO2 emissions and that's simply unacceptable for "moral" reasons, as eric c put it. You know the 11th commandment after all - thou shall not regulate carbon, for it is the holiest of elements.

http://answers.yahoo.com/question/index;_ylt=AnV6s...

*edit* eric says "Black carbon can also cause ice caps to melt.

Sea levels have been rising since the last ice age, there has been no alarming rise in sea level over the past 50 years."

Black carbon emissions have also increased due to anthropogenic activities, as it so happens. And sea level rise has indeed accelerated over the past 50 years. Whether or not you find that 'alarming' is subjective.

Also, economics and climate science have nothing to do with politics. You should really learn how to distinguish between these subjects.