Do you think that global warming is man made or is caused by natural events ?

Answer 1

Good question. This is exactly the issue the scientists are stilll debating.

First, let me mention a few things everyone (or mostly everyone) agrees on. It is perfectly natural for CO2 to be in Earth's atmosphere. It is not a pollutant, it is essential for life. Think of it as plant food. Without some of it in our atmosphere, Earth could not support life. The amount of atmospheric CO2 fluctuates normally as part of the carbon cycle. Since the advent of fossil fuels, the amount of atmospheric CO2 has gone up each year. It is generally agreed CO2 will add some warming to our atmosphere. The dispute arises when we start talking about how much. The IPCC claims climate sensitivity (the amount of temp increase from doubled CO2) is 1.5 to 4.5 C. But new research indicates climate sensitivity is much, much less and will never cause a catastrophe. See http://www.ecd.bnl.gov/steve/pubs/HeatCapacity.pdf

A key fact to consider is the recent evidence that global surface temperature record has an artificial warming bias due to poorly sited weather stations. See http://surfacestations.org for more information. All of the evidence about this is not in yet, but it appears that half of reported global warming is not even real. Stephen McIntyre reconstructed US temps using only the best stations and the warmest years in the US were 1934, 1921, 1998 and then 2006 in that order. http://www.climateaudit.org/?p=2145 It does not appear temperatures are rising dangerously to me.

Natural climate variability has been largely overlooked as a reason for a changing climate. Solar variation is only one example of natural climate variability. Climate often changes in response to oscillations in the ocean. These include Pacific Decadal Oscillation, North Atlantic Oscillation and El Nino Southern Oscillation. When these are all in their warm phase, as in 1998 and 2006, it can get quite warm. These oscillations are fairly predictable. The PDO has a 30 year cycle, the NAO about 20 years and ENSO just a few years.

There is always the possibility that the ocean may have some unpredicted event which could change climate as well. If the oceans burp, climate can change. See http://www.giss.nasa.gov/research/briefs/schmidt_02/

It seems clear that these forces are much more powerful than the impact mankind has on climate, but it is also clear that we are having some impact. But the amount of change so far is less than thought and it does not seem to be dangerous.

Answer 2

Mostly man made.

The fact that the climate has changed naturally before doesn't prove anything. The data clearly shows that this time is different.

"I wasn’t convinced by a person or any interest group—it was the data that got me. I was utterly convinced of this connection between the burning of fossil fuels and climate change. And I was convinced that if we didn’t do something about this, we would be in deep trouble.”

Vice Admiral Richard H. Truly, USN (Ret.)
Former NASA Administrator, Shuttle Astronaut and the first Commander of the Naval Space Command

Here are two summaries of the mountain of peer reviewed data that convinced Admiral Truly and the vast majority of the scientific community, short and long.

http://www.globalwarmingart.com/wiki/Image:Climate_Change_Attribution.png
http://www.ipcc.ch/SPM2feb07.pdf

It's (mostly) not the sun:

http://solar-center.stanford.edu/sun-on-earth/FAQ2.html

There's a lot less controversy about this is the real world than there is on Yahoo answers:

http://www.worldpublicopinion.org/pipa/articles/home_page/329.php?nid=&id=&pnt=329&lb=hmpg1

And vastly less controversy in the scientific community than you might guess from the few skeptics talked about here:

http://en.wikipedia.org/wiki/Scientific_opinion_on_climate_change
http://www.sciencemag.org/cgi/content/full/306/5702/1686

"There's a better scientific consensus on this [climate change] than on any issue I know... Global warming is almost a no-brainer at this point. You really can't find intelligent, quantitative arguments to make it go away."

Dr. Jerry Mahlman, NOAA

Good websites for more info:

http://profend.com/global-warming/
http://environment.newscientist.com/channel/earth/dn11462
http://www.ucsusa.org/global_warming/science/
http://www.realclimate.org
"climate science from climate scientists"

Answer 3

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. .

Answer 4

First of all, and this is an aside (though an important aside), man is a natural event.

Secondly, global warming has happened in the past prior to the evolution of man.

Thirdly, the activities of man have introduced much high concentrations of greenhouse gases into the atmosphere than would have been introduced without us.

Global warming happens but human activities are a major contributor to the current warming trend.

Answer 5

If, as man-made global warming alarmist dana1981 says, "It doesn't really matter what people on Y!A think, because there are few experts here", then why would anyone pay any attention to what he has to say?

How arrogant and full of hot air a person must be to believe other peoples's views matter little or don't matter at all, and that he is the only voice of scientific knowledge, reason and common sense in Yahoo! Only an ideological fanatic would have this frame of mind, patronizing attitude and superiority complex.

Following find 10 COMMON MISCONCEPTIONS ABOUT GLOBAL WARMING

Myth 1: Global temperatures are rising at a rapid, unprecedented rate.

Fact: Temperatures have increased around urban areas (“heat islands”) which distorts the overall picture; whereas accurate satellite, balloon and long-term mountain top measurements have observed no increase at all.


Myth 2: The “hockey stick” graph proves that the earth has experienced a steady, very gradual temperature increase for 1000 years, then recently began a sudden increase.

Fact: Significant changes in climate have continually occurred throughout geologic time. For instance, the Medieval Warm Period, from around 1000 to1200 AD (when the Vikings farmed on Greenland) was followed by a period known as the Little Ice Age. Since the end of the 17th Century the "average" global temperature has been rising at a rate of 0.6 to 0.8 degrees Celsius per 100 years; although from 1940 – 1970 temperatures actually dropped, leading to a Global Cooling scare. The hockey stick not only ignores historical fact, but is also scientifically flawed.

Myth 3: Human produced carbon dioxide has increased over the last 100 years, adding to the Greenhouse effect, thus warming the earth.

Fact: Carbon dioxide levels have indeed changed for various reasons, human and otherwise, just as they have throughout geologic time. The CO2 increase was only 0.4% over the last 50 years, rather than the 5% per 100 years quoted by Kyoto. However, as measured in ice cores dated over many thousands of years, CO2 levels move up and down AFTER the temperature has done so, and thus are the result of, not the cause of warming. Geological field work in recent sediments confirms this. There is solid evidence that as temperatures rise naturally and cyclically, the earth naturally produces more CO2 as a result.

Myth 4: CO2 is the most common greenhouse gas.

Fact: Water vapour or clouds, which makes up on average about 3 % of the atmosphere, is the major greenhouse gas. CO2 makes up only about 3% of the greenhouse gases, or about 0.03% of the atmosphere. Moreover, because of its molecular weight and absorptive capacity, water vapour is 3000 times more effective than CO2 as a greenhouse gas. Those attributing climate change to CO2 rarely mention this important fact.

Myth 5: Computer models verify that CO2 increases will cause significant global warming.

Fact: Unfortunately, computer models predicting global warming are incapable of including the effects of the sun and the clouds. Further, the main cause of temperature variation is the sun. Its radiation changes all the time, partly in cyclical fashion. The number of sunspots can be correlated very closely with average temperatures on earth, e.g. the Little Ice Age and the Medieval Warm Period. Varying intensity of solar heat radiation affects the surface temperature of the oceans and the currents. Warmer ocean water expels gases, some of which is CO2.

Myth 6: The UN proved that man–made CO2 causes global warming.

Fact: In a 1996 report by the UN on global warming, two statements were deleted from the final draft. Here they are:
1) “None of the studies cited above has shown clear evidence that we can attribute the observed climate changes to increases in greenhouse gases.”
2) “No study to date has positively attributed all or part of the climate change to ………..man–made causes”

Myth 7: CO2 is a pollutant.

Fact: This is absolutely not true. In fact, CO2 is essential to life on earth. It is necessary for plant growth and its intake causes many trees and other plants to grow more vigorously. If, as the man made global warming ideologues proclaim, CO2 is polluntant, then world thrives on it! Governments do not decide what is a pollutant- true scienice does, not junk science.

Myth 8: Global warming will cause more storms and other weather extremes.

Fact: There is no scientific or statistical evidence whatsoever that supports such claims. Growing insurance and infrastructure repair costs, particularly in coastal areas, are sometimes claimed to be the result of increasing frequency and severity of storms, whereas in reality they are a function of increasing population density and escalating development value.

Myth 9: Receding glaciers and the calving of ice shelves are proof of global warming.

Fact: Glaciers have been receding for hundreds of years; that’s because we are still coming out of the very cool period of the Little Ice Age. Ice shelves have been breaking off for centuries. Scientists know of at least 33 periods of glaciers growing and then retreating. It’s normal.


Myth 10: The earth’s poles are warming; polar ice caps are breaking up and melting and the sea level rising.

Fact: The earth is variable. The western Arctic may be getting somewhat warmer, but the eastern Arctic and Greenland are getting colder. The small Palmer Peninsula of Antarctica is getting warmer, while the main Antarctic continent is actually cooling.

Answer 6

To me it's obviously a mix of both. Yes there have been warming and cooling periods the Earth has gone through, and the Earth is overdue for one of these. However if the Earth is about to enter a warming stage this will be one of the fastest changes in Earths history. And for all of you who think Al Gore made it up, you're wrong. Watch the movie first, and then tell me what you think.

Answer 7

Both! The consequences of man made actions alters natural events. For example, deforrestation: cut down trees, deplete our oxigen source.

Answer 8

This is a natural event jest ask your self, how many ice ages have we had followed by the so called global warming and repeated how many times .It's natural not man maid .But it makes greet NEWS !

Answer 9

The fact is, this planet has been MUCH hotter and MUCH colder than it is now.

So using 200 years worth of data is meaningless.

The only thing for certain is that the average temp is up about 1 degree over the average for the last 200 years.

In the 70's the winters were so bad scientists worried about global cooling.

Answer 10

It doesn't really matter what people on Y!A think, because there are few experts here.

Scientists have determined that humans have caused 80-90% of the warming over the past few years:

http://en.wikipedia.org/wiki/Image:Climate_Change_Attribution.png

They've ruled out the Sun:

http://news.bbc.co.uk/2/hi/uk_news/6290228.stm

And it's not due to natural cycles:

"An often-cited 1980 study by Imbrie and Imbrie determined that 'Ignoring anthropogenic and other possible sources of variation acting at frequencies higher than one cycle per 19,000 years, this model predicts that the long-term cooling trend which began some 6,000 years ago will continue for the next 23,000 years.'"

http://en.wikipedia.org/wiki/Milankovitch_cycle

It's due mostly to human greenhouse gas emissions. There's simply no other plausible explanation.