Global Warming - Man made? Or natural cycle?

Scientists don't like to use the word "proof" because everything in science is subject to revision as new data comes in. But the case for human-caused global warming is about as strong as it gets.

1. If the Sun is causing the current warmth, then we're getting more energy, and the whole atmosphere should be getting warmer. If it's greenhouse, then we're getting the same amount of energy, but it's being distributed differently: more heat is trapped at the surface, and less heat is escaping to the stratosphere. So if it's the Sun, the stratosphere should be warming, but if it's greenhouse, the stratosphere should be cooling.

In fact, the stratosphere has been on a long-term cooling trend ever since we've been keeping radiosonde balloon records in the 1950's. Here's the data:

http://hadobs.metoffice.com/hadat/images/update_im...

http://hadobs.metoffice.com/hadat/hadat2/hadat2_mo...

http://cdiac.ornl.gov/trends/temp/sterin/sterin.ht...

2. If it's the Sun, we're getting more energy during the day, and daytime temperatures should be rising fastest. But if it's greenhouse, we're losing less heat at night, and nighttime temperatures should be rising fastest. So if it's the sun, the difference between day and night temperatures should be increasing, but if it's greenhouse, the day-night difference should be decreasing.

In fact, the daily temperature range has been decreasing throughout the 20th century. Here's the science:

http://ams.allenpress.com/perlserv/?request=get-ab...

http://ams.allenpress.com/perlserv/?request=get-ab...

http://www.bom.gov.au/bmrc/clfor/cfstaff/jma/2004G...

3. Total solar irradiance has been measured by satellite since 1978, and during that time it has shown the normal 11-year cycle, but no long-term trend. Here's the data:

http://www.ngdc.noaa.gov/stp/SOLAR/solarda3.html

4. Scientists have looked closely at the solar hypothesis and have strongly refuted it. Here's the peer-reviewed science:

http://www.pubs.royalsoc.ac.uk/media/proceedings_a...

http://www.mpa-garching.mpg.de/mpa/publications/pr...

5. CO2 levels in the air were stable for 10,000 years prior to the industrial revolution, at about 280 parts per million by volume (ppmv). Since 1800, CO2 levels have risen 38%, to 384 ppmv, with no end in sight. Here's the modern data...

http://www.esrl.noaa.gov/gmd/ccgg/trends/

... and the ice core data ...

http://www.ncdc.noaa.gov/paleo/icecore/antarctica/...

http://www.ncdc.noaa.gov/paleo/icecore/antarctica/...

http://www.ncdc.noaa.gov/paleo/icecore/antarctica/...

... and a graph showing how it fits together:

http://www.columbusnavigation.com/co2.html

6. We know that the excess CO2 in the air is caused by burning of fossil fuels, for two reasons. First, because the sharp rise in atmospheric CO2 started exactly when humans began burning coal in large quantities (see the graph linked above); and second, because when we do isotopic analysis of the CO2 we find increasing amounts of "old" carbon combined with "young" oxygen. Here are the peer-reviewed papers:

http://adsabs.harvard.edu/abs/1984JGR....8911731S

http://www.ingentaconnect.com/content/mksg/teb/199...

http://www.sciencemag.org/cgi/content/abstract/256...

So what's left to prove?

Global warming is one-half of the climatic cycle of warming and cooling. The earth's mean temperature cycles around the freezing point of water. This is a completely natural phenomenon which has been going on since there has been water on this planet. It is driven by the sun. Our planet is currently emerging from a 'mini ice age', so is becoming warmer and may return to the point at which Greenland is again usable as farmland (as it has been in recorded history). As the polar ice caps decrease, the amount of fresh water mixing with oceanic water will slow and perhaps stop the thermohaline cycle (the oceanic heat 'conveyor' which, among other things, keeps the U.S. east coast warm). When this cycle slows/stops, the planet will cool again and begin to enter another ice age. It's been happening for millions of years. .

Global warming (and cooling) is both a natural and artificial process. The fact of the matter is that Earth has undergone several global warming and cooling processes. But how are humans contributing to it? We can compare it to a major natural factor. Volcanoes. During and after a volcanic eruption, carbon dioxide, sulfur dioxide, and ash are produced. 3/3 of those dynamics participate in global cooling, and 2/3 partake in global warming. Common knowledge says that the sun's radiation is what warms the Earth and provides us with energy. When carbon dioxide and other such greenhouse gases are emitted into the air, the albedo percent increases. Radiation waves enter the atmosphere, are absorbed or bounce of the surface of the Earth, and (those that bounce off the surface) are released back into space. However, many rays are trapped because of clouds, molecules, atoms, and air and other particles reflect them back to the Earth's surface. Due to the constant discharge of carbon dioxide (the burning of fossil fuels), mankind is acting in the same manner, just at a faster rate. By the thickening of the Earth's albedo, or the secretion of greenhouse gases, humans are affecting the rate of global warming, though it is not entirely artificial.

Both. It is a natural occurrence, but it would not be happening this quickly naturally if there weren't some outside contributer to the amount of CO2 in the atmosphere. If you look at graphs and tables for the years and amounts of CO2, you can see that an increase happened right around the Industrial Revolution about 200 years ago. Global warming and the pattern of climate change is happening on fast forward mode.

Mostly (75%-95%) us. Many scientists have addressed this question head on. One of many studies summarized here, from the Source below.

http://www.globalwarmingart.com/wiki/Image:Climate...

Sharon K is a one smart cookie.

"by the close of 2008, we will no longer be in the "warmest decade on record" - the record of course being only about 100 years long anyway. Within that temperature "record" the years 1999-2008 will not be the "warmest decade."

Nice trap, it will be 1998-2007 instead. Not exactly a killer argument against very recent warming, since it includes the obviously very unusually warm year 1998 (and the recent very warm years), which you cleverly leave out of 1999-2008.

I'll bet you that the 5 years from 2004-2008 will be warmer than any five year period in the past hundred years. That way, you can't use both 1998 AND the recent very warm years as a trick to win. 1998-2002 ain't gonna cut it.

But I'm very impressed at your coming up with this one. Cleverest argument by a "skeptic" in a very long time.

Your right about having doubts most AWG alarmist think they infallible.Yes we are contributing to pollutants but not on the scale they state.Do yourself a favor go to any NOAA or AWG site and take a real look at the testing methods used.You might have to look on the very last page of each but there you always find a disclaimer or a limitation to the methods.As of to date, ice core sampling is the best they have.The weather even affects the readings.This doesn't mean it isn't a valuable tool,it just means it has major limitations.Yes the old ways do need to change I just don't like the God like attitudes.

Its a natural cycle. All of our weather is a cycle from temperature to precipitation.

In the 1970's it was cold and all these "scientists" were crying about global cooling. We were going to freeze if we didn't stop polluting. This did cause us to clean up a lot of our pollution which was a very good thing though.

The 1930's had some of the hottest temperatures ever recorded all over the world.

The 1700's were very cold.

The middle ages were warmer than now.

Earth has been through several ice ages. Humans had nothing to do with making it get that cold or hot enough to end them.

Al Gore is probably the biggest hypocrite out there. He flies around in a private jet and has several huge houses that use more power in a month than most people use in years.

Sharon's right. The latest temperatures show that it's actually been cooling some since 1998.

1998 seems to be an odd year. I think it was "el nino" or something, but it stands out as way above more recent years, except for 1934 which remains the hottest year on record, according to NASA.

You're right though. Most scientists are now saying they don't think humans cause climate change. I can't believe we wasted so much money and time on such nonsense.

in the most part i believe it's a cycle but we humans are contributing to ot greatly

we all know the earth has been through an ice age right. well if we went through an ice age it isn't out of the question that our planet could go through the opposite and heat up, which is what we're doing. Indeed the earth travels in orbit around the sun on a tilted axis of 23 degrees well we get closer and farther from the sun while in orbit hhhhm maybe we're in orbit closest to the sun. that doesn't mean oil greedy humans like you and i aren't contributing to global warming. We are all polluting in little ways, i think it would be benificial for the united states to be energy independent not relying on foreign oil and getting us into wars "we call atacks on terrorism" but thats another topic and i'm not degrading bush i respect him as our president. anyways if the us was energy independent relying on solar energy and power plants and other means we could focus on our country and make it a better place to live FREE OF POLLUTION.....

If you want to read about evidence for a natural cycle of Earth, shown through evidence found in stalagmites, tree rings, drill holes, ice holes, archeology, pollen study, biology, seabed drill holes, seabed rafts, tax collection documents from hundreds of years ago, geologic study of rocks, astronomical studies of the Sun's orbit about the Milky Way (cosmoclimatology) to name a few, and how myths of global warming consequences are perpetuated (like sever weather, there was little severe weather during the last two warming periods), you should read the following book in the link. The books points to a 1,500 year temperature cycle, that is contained within many other cycles. The book also uses known human history that occurred during those times to refute many myths about might what might happen with global warming. The book is only $14, and is completely referenced.

For a recap of other ideas or climate scientists that diasgree with the IPCC, use the 2nd link to read about 400, named scientists with links and summaries of their diagreements.

For anyone to say that anthropogenic global warming is a proven fact has little understanding of the basic tenets of science.