what do man- made global warming skeptics mean by saying natural occurence of climate change?

Well considering that there have been at least three climate optimums over the last 8,000 years where the arctic was virtually ice free during the summer months. In fact during the late 30s through the mid 40s the Arctic Ocean was more ice free than it has been recently. The bears and other animals of the region are adapted to survive the current climate as they have survived the Holocene optimum that was up to 6c hotter than we are currently and this lasted close to 2,000 years, maybe more. The Roman optimum was about 4c to 5c hotter than it is currently and this lasted close to 500 years/ The Scandik/Medieval optimum lasted about 500 years with one minor cooling called the Oort minimum where it cooled to about the climate we have currently. But through most of it temps were 2c to 4c hotter than the current maximum.

Knowing the history of the world reasonably well helps a lot to see the outright lies the promoters of AGW continually make.

First lie.

In the last 50, 100 or 150 years temperatures have risen faster and higher than any time in history.

Truth is, in every previously recorded climate optimum period it has gotten hotter faster than it has currently. In fact the year 1400 warming went from the bottom of the wolf minimum to a peak 3c hotter than our current maximum and down to the bottom of the Sporer minimum the coldest part of the little ice age in about 100 years.

Second lie.

It has never been this hot in all of history.

Truth is that at least 3 times in the last 1,000 years it has exceeded our current temperature by up to 5c, once for several hundred years.

Third lie

The Arctic Ocean has never been this ice free in history.

Truth is that during the Holocene, Roman and Medieval periods the Arctic Ocean was navigable most of the year most of the time. It was even more navigable during WWII than it is currently.

So it is not very difficult for anyone with a decent basic education to put the lie to any point the AGW crowd use to sell their pogrom to the less well educated.

The real problem here is believers cherry pick the evidence they want made public while skeptics feel that the general public should be allowed to learn the full truth about climate variations. Believers on the other hand only want the public to know about selected items that can be spun to favor their political pogrom.

The so-called skeptics here are for the most part in denial about the science used to present a case for human-related climate change. Natural cycles exist, no doubt about it. But there's little room for doubt these last 5 years that human activities, particularly since the start of the Industrial Age and the use of fossil fuels, have accelerated and shifted natural cycles.

Don't let anyone here tell you what's right or wrong, what is or isn't happening. Read some books, review some websites, check out the science, and you'll begin to develop a better understanding of how the natural cycles work and how humans have influenced the cycles. It was mostly when the politicians understood the cost of inaction that things really began to happen. Now most governments are in various stages of identifying action plans, of working on mitigation, and adaptation. That's our work for the foreseeable future.

A few sites below that served me well when I was getting up and running on the topic. I find them to be reputable sources all. As far as books go, I just finished "The Great Warming" by Brian Fagan. "Heat" by George Monbiot is next on my reading list, but comes highly recommended. "Deep Economy" or "Hot, Flat and Crowded" can help add a unique perspective to the mix, too.

well it just depends on the skeptic, they cannot even decide on an alternate explanation.

Some claim it's the sun

Some claim it's another cycle

Some claim cosmic rays

Some claim it is from within the earth

problem is: none of these have any evidence to back them up

only enhanced greenhouse effect provides an explanation and the observations to back it up.

"climate naturally fluctuates" and there is always a reason for the fluctuation.

So far only greenhouse gas provides the data and observation based explanation for the current warming trend, the others are faith based - they have no data or observations to back them up, scientifically they are nonsense.

I find the first person to answer is either a radical believer or someone who dropped out of school before the 6th grade. The major point skeptics make is there is no evidence trail to even generate a working hypotheses for AGW or GCC as advertised. Yes the climate average is slightly warmer now than it was in the 1800s when we were coming out of a unusual cold spell known as the Dalton solar minimum. In fact there were 4 solar minimums in just a few hundred years that created the climate minimum known as the little ice age.

Why there is no problem;

We are well short of the maximum climate average of the last 2,000 years and we are still more than 1c below the mean average temperature of the last 4,000 years.

During at least 2 of the last 4 documented climate optimums the Arctic Ocean was virtually ice-free for more than 100 years according to Viking and Inuit records. We are not even close to that.

Historian’s and working scientists know that we are well within the normal climate fluctuations of recorded history. If it ain’t broke why try and break it!

Global warming/cooling is cyclical. We have been in a warming stage since the end of the last ice age approx. 10,000 years ago. Eventually, if the planet survives, we will enter another cooling stage in approx. another 100,000 years or so. The problem is that the temperature change even if it is only 8 degrees will change the planet forever. Remember this cycle has happened at least 10 times already, but all before humans arrived.

Really not a bad question that may have perspective. The distinction lays within the boundaries of what normally occurs as opposed to what is/or can occur. As far as numbers go, it's just about all natural. The increase of 1 to .5 degrees has become a issue to nominal temperatures. Of which nobody has been able to explain, what a normal/optimal temperature is. Yet we see a rise in CO2 and justify the unknown temperature accordingly. So this minimal increase that really doesn't occur everywhere (median temperature) has become blown out of proportion.

When people say that it is a natural occurence, It is... Buuuut when humans came we have sped up the process of global warming by sooooo much.... It is mostly because of CO2 emmisions (it goes up into the air and stays in the atmosphere traping the suns heat which in turn... Global warming) and humans let off so much CO2 by cars, making of plastics and so on and so forth. So global warming is happening way to fast... it shouldnt happen that fast... Main cause... Humans.

James said it well. The first answer was typical alarmist carpola. It wasn't even close to the truth. As a geologist, I can assure you that climates naturally fluctuate. There was a Maunder Minimum with very few sunspots a few hundred years ago. We have been warming since then. There is very little indication that recent warming is out of the norm in spite of alarmists attempts to blame humans.

Simply put, if man is the sole cause for global warming - then HOW did the earth warm up after the last ice age? When there WERE NO machines, factories, automobiles, etc.?

It's a very vague and unscientific argument. Basically it goes that because the planet goes through natural climate changes (mainly caused by the Earth's orbital [Milankovitch] cycles and variations in solar output, amplified by CO2), maybe the current global warming is part of one of those cycles.

Of course, climate scientists have considered that possibility and ruled it out, as discussed in the link below.