Is global warming really caused by humans?

Question

I know there is alot of hype about global warming nowadays and everyone is going "green", but is it really something we are doing or is it maybe just a temporary change in our climate? Please leave any infomation you have on the subject. what you think, why, scientific evidence......(not just the rantings of crazies like Al Gore please).

Answer 1

As a geologist, and I think any geologist worth the paper his degree is printed on would agree, I see things in a longer time interval than most it seems. Some people, particularly liberals in this case, see the world only in the last decade. A basic knowledge of geology reveals that the earth has been warming for thousands of years. Only the most idiotic global warming alarmist would blame that on humans (and believe it or not there are those out there that try). So it has been generally warming since we came out of the last period of glaciation 10,000 years ago. This is due primarily to oscillations in our orbit around the sun. Recent warming and cooling trends are mostly due to variations in the sun due to numerous cycles that are poorly understood mostly due to magnetic anomalies and to a lesser extent solar output. Humans have released some CO2 and are likely to be responsible for a small percentage of the warming. In all likelihood, it would have warmed anyway since that is the trend and our contribution is smaller than the natural rise in spite of what Bob or others claim IMO. There is no evidence that CO2 has driven the climate in the past. They push an agenda that has less to do with science and almost everything to do with politics.

Answer 2

I dint really know so ill rant and rave . If it is by man then there's no harm in trying to fix it . If it isn't by man then there's no harm in trying to fix it . Look at it this way the only thing its doing is getting people interested in alternative energy . Gas is up to $3.09 in MI today heat bills hit the roof cooling bills just as bad . Turn your lights off don't watch TV stay off your computer . Another words sit there shut up and do nothing . Is this how you want to live?

Like i said the only thing global warming is doing is forcing people to think of an alternative energy and whats wrong with that . Aren't you sick of going to work just to hand your money over to the gas ,light . and gasoline company's ? Do you enjoy breathing toxic cancer causing air .

If its man or not causing it we are going to have to have energy to survive it so if its a big lie then its for a damn good cause and we could use more lies like that.

Thank God for ranting people like Al Gore .The only crazies i see are people who like living in a polluted world that do not want change

Answer 3

Yes we are causing it. Sure the arguements that the current increases in average temperature could be part of a natural cycle have validity. But consider the amount of heat energy the human race has released into the atmosphere since the begining of the industrial revolution. Even without the greenhouse effect, that amount of energy has surely overwhelmed the planets natural cooling process.

Answer 4

there's no doubt humans have a hand in the global weather change. but if you do some research, you'll find mother nature changes thing every few thousand years. dry, floods, ice. there's not much the old gal can't do. if gore really knew what he's talking about, he'd be in the white house.

Answer 5

Mostly caused by us (about 80-90% of the warming over the past 30 years is due to human greenhouse gas emissions).

Basically we know it's warming, and we've measured how much:

http://www.ncdc.noaa.gov/img/climate/research/2005/ann/global-blended-temp-pg.gif

Scientists have a good idea how the Sun and the Earth's natural cycles and volcanoes and all those natural effects change the global climate, so they've gone back and checked to see if they could be responsible for the current global warming. What they found is:

Over the past 30 years, all solar effects on the global climate have been in the direction of (slight) cooling, not warming. This is during a very rapid period of global warming.

http://news.bbc.co.uk/2/hi/uk_news/6290228.stm
http://www.pubs.royalsoc.ac.uk/media/proceedings_a/rspa20071880.pdf

So the Sun certainly isn't a large factor in the current warming. They've also looked at natural cycles, and found that we should be in the middle of a cooling period right now.

"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

So it's definitely not the Earth's natural cycles. They looked at volcanoes, and found that

a) volcanoes cause more global cooling than warming, because the particles they emit block sunlight

b) humans emit over 100 times more CO2 than volcanoes annually

http://www.gaspig.com/volcano.htm

So it's certainly not due to volcanoes. Then they looked at human greenhouse gas emissions. We know how much atmospheric CO2 concentrations have increased over the past 50 years:

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

And we know from isotope ratios that this increase is due entirely to human emissions from burning fossil fuels. We know how much of a greenhouse effect these gases like carbon dioxide have, and the increase we've seen is enough to have caused almost all of the warming we've seen over the past 30 years (about 80-90%). You can see a model of the various factors over the past century here:

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

This is enough evidence to convince almost all climate scientists that humans are the primary cause of the current global warming.

Answer 6

Global warming as defined by the UN is only caused by humans. For them there is no other kind of warming.

While pollution control in the US is a milti billion dollar business, we need to do more and all we can to limit the pollution and possible ghg's into the air.

The first start should be to start building more nuclear power plants, as 50% of all ghg's in the USA are from power generation.

Answer 7

We can conclusively say:

- That human beings used in a span of 200 years significant quantities of carbonated fossil fuels accumulated in layers during millions of years.
- The primary use of these carbon fuels is for combustion which releases CO2 in the atmosphere. Most of this added CO2 has not been in the atmospheric carbon cycle for millions of years before human activity started.
- CO2 is a greenhouse gas.
- An increase in CO2 concentration leads (among other effects) to an increase of the greenhouse effect.

Answer 8

Yea I think we have some part in it but studies show that the weather has drastically changed every 10,000 years or something like that they have ice core samples to prove it, I think the earth is just on the verge of shifting it's climate, yea things are going to be different, and by going green will help yes, but I don't think it will stop the earth from doing what it's been doing for many years.

Answer 9

Mostly caused by us. The proof is enormous, from all angles, so this will be long. And the real scientific proof is in the links.

It's hard to read them all, try the first and the second of the last 4. That nay do it.

This is science and what counts is the data.

"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://ipcc-wg1.ucar.edu/wg1/wg1-report.html
summarized at:
http://www.ipcc.ch/SPM2feb07.pdf

It's (mostly) not the sun:

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

And the first graph above shows that the sun is responsible for about 10% of it. When someone says it's the sun they're saying that thousands of climatologists are stupid and don't look at the solar data. That's ridiculous.

Science is quite good about exposing bad science or hoaxes:

http://www.cs.cmu.edu/~dst/ATG/polywater.html

There's a large number of people who agree that it is real and mostly caused by us, who are not liberals, environmentalists, stupid, or conceivably part of a "conspiracy". Just three examples of many:

"Former Republican House Speaker Newt Gingrich challenged fellow conservatives to stop resisting scientific evidence of global warming"

"Our nation has both an obligation and self-interest in facing head-on the serious environmental, economic and national security threat posed by global warming."

Senator John McCain, Republican, Arizona

“DuPont believes that action is warranted, not further debate."

Charles O. Holliday, Jr., CEO, DuPont

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/412.php?lb=hmpg1&pnt=412&nid=&id=

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 10

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_images/global_upper_air.png
http://hadobs.metoffice.com/hadat/hadat2/hadat2_monthly_global_mean.txt
http://cdiac.ornl.gov/trends/temp/sterin/sterin.html

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-abstract&doi=10.1175%2F1520-0450(1984)023%3C1489:DDTRIT%3E2.0.CO%3B2
http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F1520-0477(1993)074%3C1007%3AANPORG%3E2.0.CO%3B2
http://www.bom.gov.au/bmrc/clfor/cfstaff/jma/2004GL019998.pdf

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/rspa20071880.pdf
http://www.mpa-garching.mpg.de/mpa/publications/preprints/pp2006/MPA2001.pdf

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/law/law.html
http://www.ncdc.noaa.gov/paleo/icecore/antarctica/domec/domec_epica_data.html
http://www.ncdc.noaa.gov/paleo/icecore/antarctica/vostok/vostok_data.html
... 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/1999/00000051/00000002/art00005
http://www.sciencemag.org/cgi/content/abstract/256/5053/74

This is NOT just a temporary blip on the radar screen. CO2 has been rising exponentially since WWII with no end in sight. Further, the CO2 we emit today stays in the air for decades to centuries, causing more warmth during that entire time.

Even worse, much of the CO2 we emit today is absorbed by the oceans, but as the oceans get warmer they will absorb less and less, and eventually start emitting back into the air some of the CO2 we created in the 20th century.
http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=11089968&dopt=Citation

We need to reduce carbon emissions soon, and drastically. Similar sudden temperature increases in the past have resulted in global mass extinctions, and that's what we're facing in the near future: half of all plant and animal species wiped out.
http://www.sciencedaily.com/releases/2007/10/071024083644.htm