Global Warming??

Question

I've heard conflicting opinions about global warming. Some people say that it's just a natural course of events and we have nothing to do with it. Does anybody have an opinion about it?

Answer 1

1. "Inspection of the global atmospheric temperature
changes during the last 1,000 years (Fig. 11) shows that
the global average temperature dropped about 2C over
the last millennium. This means that we live in the cooling geologic epoch (which comprises most of the Holocene), and the global warming observed during the latest 150 years is just a short episode in the geologic history. The current global warming is most likely a combined effect of increased solar and tectonic activities and cannot be attributed to the increased anthropogenic impact on the atmosphere. Humans may be responsible for less than 0.01C (of approximately 0.56C (1F) total average atmospheric heating during the last century)."

2. Despite the increasing trend in atmospheric CO2 concentration, the patterns of 20-year and 60-year oscillation of global temperature are all in falling. Therefore, if CO2
concentration remains constant at present, the CO2 greenhouse effect will be deficient in counterchecking the natural cooling of global climate in the following 20 years. Even though the CO2 greenhouse effect on global climate change is unsuspicious, it could have been excessively exaggerated. It is high time to re-consider the trend of global climate changes."

3. "Physical, mathematical, and observational grounds are employed to show that there is no physically meaningful global temperature for the Earth in the context of the isue of global warming. While it is always possible to construct statistics for any given set of local temperature data, an infinite range of such statistics is mathematically permissible if physical principles provide no explicit basis for choosing among them. Distinct and equally valid statistical rules can and do show opposite trends when applied to the results of computations from physical models and real dta in the atmosphere. A given temperature field can be interpreted as both 'warming' and 'cooling' simultaneously, making the concept of warming in the context of the issue of global warming physically ill-posed."

4. "The Arctic was as warm as or warmer in the late 1930s than it was at the end of the 20th century. "

There are four premises that underly AGW:

1. That 1990 levels of CO2 are the appropriate baseline.

Why was this year chsoen? Is there some sort of scientific basis for this? Or was it arbitrary?

2. Global temperature is a meaningful statistic.

It could be argued that basing decisions on meaningless numbers is a fools errand.

3. Global temperature and CO2 levels are intimately linked.

It has been argued that they are linked, except that temperature leads CO2, not the other way around.

4. CO2 drives global temperature.

There are two gases that have a stronger greenhouse effect, relatively speaking, than CO2. They are methane and water vapor(not from clouds, which are droplets). These should have a greatet effect than CO2.

Outside of any of the arguments regarding the causes of warming (solar variability, cosmic rays, tectonic heating, volcanic emissions, CO2 emissions, CH4 emissions, Milankovitch cycles, etc) I question these four underlying premises of global warming itself.


If my interpretations are correct, global warming is hogwash. If my interpretations are incorrect, I am wrong. I don't mind being proven wrong, it is a good way to learn about things that I have overlooked.

Answer 2

Our planet has what you could describe as a very restless climate - it's always doing one thing or another, if it's not warming up then it's cooling down and this has always been the case.

In the past there have been at least four occasions when Earth was considerably warmer than it is now and all the ice had melted. There have also been times when it's been much colder and there's been far more ice. In nature these changes occur very very slowly, over many millions of years.

In recent times (in a geological sense) we've seen a rapid rise in temperatures starting 18,000 years ago and this is what led to the most recent glacial retreat. Over this period Earth has warmed by 9°C - that's a lot. It's still only an average of one degree in 2000 years but in terms of natural variation it's extremely fast.

However, what can't be explained by any natural event is the unprecedented rise in temperatures we've wtinessed since the dawn of the Industrial Revolution. This is the time when humans started punping large quantities of greenhouse gases into the atmosphere.

We know how greenhouse gases allow heat from the sun in (solar radiation) and how they prevent heat from Earth escaping (thermal radiation), the more greenhouse gases there are the more heat gets trapped.

We're at a point now where levels of greenhouse gases are more than has ever been known before (385 parts per million by volume of CO2 compared to the highest natural level of 310 ppmv). This blanketing effect is causing temperatures to rise at an unprecedented rate (16.4 times the natural rate in the last 100 years, 31.2 times the natural rate in the last 25 years).

There are conflicting opinions and sometimes it can be difficult to know who and what to beleive. It's important therefore to look at the evidence and to question what you read and hear.

As a previous answerer has said, rely on the facts, not opinions and in this repsect you may like to visit a website |'ve created which explains global warming and climate change based on facts - http://profend.com/global-warming/pages

Answer 3

The facts are that mankind's contribution to global climate change, if any, cannot be determined from available temperature data.

The opinions are that mankind is responsible for everything bad in the world -- including weather and climate, because anyone that enjoys a standard of living higher than freezing in a tee-pee, and watching their children die of diptheria at age five, has to be raping the environment.

The earth is, right now, currently within an ice age, because glaciers cover Greenland and the Antarctic.

New York city was under a mile of ice 10,000 years ago, since then then the earth has warmed and the glaciers have retreated.

During this overall warming, the earth has been warmer than temperatures we experience today, and cooler than today. Exactly how much warmer and cooler, is not precisely known.

Since the temperatures today are within this normal variance, mankind's contribution to climate change, if any, cannot be determined.

Climate is an extremely complex non-linear, coupled, chaotic system that even in theory, cannot be precisely modeled. In particular, volcanos spew dust into the atmosphere which cools the earth and there is no climate model that claims to predict volcanic action. An eruption of the Yellowstone super volcano would abruptly drop global temperature that would make life very difficult for humanity.

There are many threats to humanity that are better documented and vastly more destructive, including total thermonuclear war, a large meteor strike, and an influenza pandemic.

The downside of a (perhaps) rise in temperature of a few degrees over the course of a 100 years, is just not in the same ballpark.

That is why politicians could care less about climate change. You think telling people they have to lower their standard of living so they can enjoy COLDER winters is going to resonate with anyone?

Answer 4

Certainly climate change is natural. If not why did previous ice ages retreat? And why were there previous ice ages anyhow if the climate didn't change? We know that the climate is changing all the time.

The current controversy about global warming is really about how much human are contributing to the warming. We know that the earth would be warming even if there were no humans. Some people think that human generated carbon dioxide and other greenhouse gasses are contributing to the warming. How much we are contributing to the total is hotly debated.

We can't stop global warming. Even if every human disappeared today the earth could continue warming for centuries. That's the conclusion of the United Nations Intergovernmental Panel on Climate Change. We may be able to slow the warming but we can't stop it. How much can we slow it? Nobody knows for sure.

Answer 5

Of course human impact will have some effect on the climate, that has been proven, but the level over how much is up for debate.
It doesn't matter anyway because global warming is the earths response to a unnatural change in climate. If we (mostly India and China) pollute to much this creates tsunamis, drought and then death. Luckily for us this death will occur in poor heavily populated areas.
What can we in the west do? If we drive hybrids the marginal impact is soooooo small. Poor nations will continue to pollute at a much greater rate. If you really want to stop global warming go kill some Chinese (a joke).

Answer 6

You have hit the nail on the head -- there are facts and then there are opinions. The opinions are what are causing the controversy.

Global Warming is a fact and has been occuring for 10,000+ years. Man contributes to it, but the question is how much. In the U.N. report they state that it is occurring at rate which cannot be explained by natural forces alone. (In other words, "man is a contributor -- not the cause" of global warming.)

It has become a political topic and grossly distorted by the politicians and the news to make it seem that man is the sole cause of global warming. They have their own reasons for making it seem that man is the cause and that we can do something to reverse it.

Read all the FACTS you can find and ignore the opinions until you know enough about it to sort out the hype from the reality. You will then see that much of the controversy is political and not scientific. (Whenever you hear "all scientists are in agreement" about anything, you know they are lying!)

Answer 7

I put it largely to do with the natural cycle. Humans do have an impact on the climate but I think it's more to do with pollution and deforestation than it is to do with 'global warming'. Particularly this CO2 business - CO2 doesn't cause higher temperatures, higher temperatures cause more CO2. Even Al Gore's little graph on his documentary showed that if you look properly at it.

It's mostly natural with a hint of human impact in the areas they don't seem to be focusing on at the moment, which is probably why people question the science so much. I wouldn't so much say we cause global warming, as we cause localised climate change not related to warming the planet up.

Answer 8

I personally believe the theory of anthropogenic global warming is quite solid. And I have, at present, seen a grand total of three arguments against it which I haven't been able to refute using simple climate data (mostly to do with increased solar irradiance, something I know absolutely nothing about).

I believe the science is fairly conclusive on the issue, and myself, being a little lemming, always follow the science.

I don't want you to take my or a single other person's word in this thread on it though. Do your own research (into both sides of the argument) and make up your own mind about it.

Edit: And here is a nice place to start. The author of the article seems to believe in AGW, but the article itself is mostly neutral on the issue.

The whole thing was made with standard climate graphs that can be found in most any basic paleoclimatology textbook.

http://math.ucr.edu/home/baez/temperature/

Of course, going by my mantra of being skeptical of both sides of the argument, you'll probably need to do a little research and decide whether you think the graphs are dependable.

I also like what one poster said above me, "science is about data, not clever arguments". It doesn't matter in the end which side 'wins', what matters is that we discover the truth. That's what science is about, after all.

Answer 9

global warming is a natural course of events, the climate of planet earth has been changing ever since it came into existance billions of years ago. however, because of the huge amount of carbon dioxide we are putting into the atmosphere, the earth is holding more heat as a result. so it is a natural event, but human activity is accelerating it.

Answer 10

I personally think that the ice caps melting is not a good sign. Whether or not we can point the finger at humans causing it may not matter if there are consequences to a significant change in the Earth's albedo. I recently spoke to a friend of mine who has a Ph.D. in geoscience, and has spent her life working in that field. She said that temperature changes do occur over the course of Earth's climate history. We've had ice ages and tropical rainforests where there is now desert. Still, I happen to think air pollution is connected to global warming, and that it is a measurable fact that the polar caps are melting, and that the rate of melting is increasing.