Are Humans reponsible for global climate change or is it part of Earth's 4.5 billion year old cycle?

Al Gore is responsible for global warming.

It's hard to tell how much of the change we are responsible for, but there is a lot of evidence pointing to the fact that the amount of greenhouse gas we have released (see source for a graph depicting CO2 concentrations in the atmosphere over the past 1000 years) would cause a large change in the climate, and reducing the amount of greenhouse gasses in the atmosphere would lower the average temperature of the global climate.

What we have done to the atmosphere isn't entirely unique in earth's history except in how fast it has occured (a couple centuries, which is a mere instant on a geological time scale). Here is the important point though: the earth can survive a lot, but that doesn't mean any specific species, including humans, can.

The earth has gone through more extreme changes than we are talking about with global climate change currently, and there is still life on the planet, but the thing we should be concerned about is whether civilization as we know it can survive the change that is occuring now, whether or not we are causing it. The answer is not certain, which is the scary part. However, with the simpicity and external benefits of things we could do to help move the climate in the other direction, it is certainly worth our effort to undo climate change, whether it is our fault, or part of the earth's cycle.

The reality is that WE are part of the earth's 4.5 billion year old cycle, and WE are not even the most extreme thing to have happened to it. But if we want to survive we had better start paying attention to what parts of the earth's cycle affects us, how we can affect them, and make sure we are prepared for whatever is coming.

And in response to the post about humans having no effect and it being "arrogant" to think we do - that is an intuitive bit of science fiction, but is actually irrational to believe, especially given the rising human population. It is true that it takes a lot to change the global climate, and also that nature as a whole has more power to change it than we alone - only part of nature - have, but if you take a look at how much we have changed the concentrations of greenhouse gasses in the atmosphere it is easy to see that humans as a race with over 6 billion members can have a huge impact regardless of how insignificant one person's actions seem. As for the anecdote about Greenland and Iceland, there is no evidence that Greenland was named for it's landscape, and Iceland hasn't been covered in ice since the last ice age; when humans arrived it was 25-40% birch forest. The countries have misleading names - see my second and third sources.

The earth's age has a definite bearing on the global climate change. But it was for balancing between the various forms of nature such as air, water, atmosphere, land and heat. As long as the intereference with these were small, the changes took place also was slower. The new inventions added to the change in the environment be that may be mining, construction, industries, chemicals all have contributed for global warming. This can be contained in the sense the rate at which these could change can be minimised if we further do not play with the nature. Felling of trees has a greater role and the second is the pumping of industrial waste. This way the humans also are responsible.

Ramachandran V.

The Earth goes through a number of variations in its heat retention cycle. At some times, the planet is holding onto more heat than it radiates, resulting in a warming phase. At other times, the earth radiates more heat off than it receives, resulting in cooling.

There are many factors involved in this, such as the periodicity of the orbit, solar activity, geological activity, and yes, the presence of lifeforms. Ever since flora and fauna has been around, they have changed the way heat is converted into mechanical work, so they do have an effect on the nature of the planet's temperature cycle. Humans are no different.

I think the actual question is if human activity is altering the temperature patterns significantly due to developed methods. I believe that this is the case, ranging from the beginnings of agriculture to the modern industrial economy.

However, a more germane question becomes whether or not this is desirable. I believe that a lot of people do not desire it primarily because they have become familiar with current climate conditions and do not want to change. I think that a subset of this group feels that somehow it is not humankind's role to alter the environment.

Nevertheless, humankind is a part of nature. We ARE going to affect climate change. The question is how and to what degree. I feel that we need more study to see how it might be happening without our influence before we start debating how our economies are going to be altered by this.

I believe the answer is a combination yes of both. The earth would go through it's cycles with or without us being here. Now as to weather we have an effect on it's climate, I would have to say that yes we do have an effect. To the degree of effect is debatable, but most likely unprovable. The rate at which are climate is changing is most likely faster than if we were only populating this earth by a small % of it's current 6.8 billion humans. So the real question is, is the rate of climate change going to be too fast for the worlds living creatures to survive. The domino effect has begun. We can only do our best to be less invasive, and hope that the effectual rate of change is less than what would eliminate us. JMHO

The amount that humans are adding to it is insignificant. I can name two of the top climate scientists in the world (one of whom is the professor of atmospheric science at MIT - pretty impressive credentials, I'd say) who say that, basically, the Al Gore movie is alarmism, and nothing more. It ignores some very basic facts about the history of the climate of the world, and therefore presents what some scientists see as the sky falling, when in fact, there is no reason for alarm.

Btw, I don't buy the idea that the earth is billions of years old. That has not been established by science (or any other field), and most of the indicators of how old the earth and universe actually are suggest that it is closer to 10,000 years old, not billions. It (the billions of years) is part of the required time for Darwinism to have happened (even tho' Darwinism is impossible), so the major "official" science outlets spout it continually as if it were fact. They understand the truth of what Stalin said - "if you repeat a lie often enough, people will come to believe it."

I would have to say that we humans would have to have at least some of the responsibility for climate changes. The building of vast oceans of cement that we call cities, generates a massive amount of heat, pollution, and other things that affect the atmosphere. We can surmise that some sort of cycle of climate change is part of the Earth's cycle, but there would be no empirical way of determining this, since we only see a tiny portion of what might have happened 4.5 billion years ago.

Virtually any answer to to this, would be mostly supposition and guess work.

There are many reasons that global warming takes place. Scientist can see by looking at the environment (IE polar ice caps) that this is something that the earth has always done. Now, have we as human affected the plant on which we live? Of course. Have humans been the sole reason for the climate change, doubtful. But in the end one can't say for sure, there are only inferences based on what we have recorded and what we are still trying to figure out. Should we change our energy consumption? You betca ya! And what's the best way to get any body motivated enough to change a system that large?? Perhaps global warming is enough motivation to get people busy.......

I believe this is part of a cycle that the earth goes through form time to time. We do effect it some, but not as much as we would like to think. With the possible eruption of several volcano's that are predicted. we could soon be facing a global winter and famine from cold.

The eruption of Krakatoa was one of the most recent eruptions that lowered the earth's temperature.

The most recent VEI-8 eruption was at Lake Toba, Sumatra, and occurred around 75,000 years ago, plunging the Earth into a volcanic winter and eradicating 60% of the Human Population. The Lake Toba eruption was responsible for the formation of sulfuric acid in the atmosphere and the Millennial Ice Age.

Maybe we should hope we have some global warming so when the next big eruption does happen and it lowers the earth's temperature, it will just cool it down to normal. Meanwhile, build a greenhouse in your backyard; just in case.

Yes, and yes, and no.

Of course the Earth's climate cycles. It always has, and it will for as long as we have an atmosphere. But humans are impacting the atmosphere in a profound and previously unseen way. We're pumping way more pollutants into the air than the Earth has ever seen before, and the Earth has no way of sustaining itself in its present state. Right now, the Earth, if humans weren't around, may well be ready to shift climates again anyway. However, I believe that the shift that is about to occur is going to be much more drastic than what's been seen in the past simply because of the impact of human life. I certainly think that what ever happens with our climate is going to be much more drastic than anything our society can handle.

We have to start making changes now and hope that we can cancel out some of the damage we've done.

Yes, humans bare the responsibility for global warming. As you state in your question, Earth has a 4.5 billion year life so far, and in that time there has only been one occupant that has the ability to inflict such drastic changes, as someone else put it, the industrial age, has made a huge impact on our planet.

Has it ever happened before we came along? What about the Ice age you say? well lets think about that shall we. The planet was frozen, then it warmed and melted the ice, I don't remember a freeze like that in the last thousand or so years, do you? Earth may have a cycle that includes global warming, but it's not scheduled anytime soon. As for why or how we caused it, who knows for sure, but it's a certainty that we haven't helped matters. Hope this helps.