Can you describe the causes of global warming?

Question

Increasing temperatures are a reality. But what is the cause?

Most say carbon dioxide is a main contributor. Is this true? Can it be proven?

What percent contribution to global temperature increase is from carbon dioxide?

What percent contribution to global temperature increase is from natural variation of the sun?

If the current trend in temperature increase is from carbon dioxide, what caused past increases?

How do those who run global climate models validate estimated temparature data from centuries ago, when accurate temperature measurement was not yet possible?

How is the computer code for global climate models verified and validated? Who does this?

Robert, The EPA site is one of the reasons for my question. Please look. It includes statements such as "...uncertainties associated with this statement increase substantially backward in time. Very little confidence can be assigned to estimates of hemisphere average or global average temperature prior to A.D. 900 due to limited data coverage and challenges in analyzing older data."

and,

"...climate models are imperfect. Their simulation skill is limited by uncertainties in their formulation, the limited size of their calculations, and the difficulty of interpreting their answers that exhibit almost as much complexity as in nature."

So...my questions still stand unanswered, paraphrased: how can we validate past temperature estimates and algorithms used to predict future warming?

WMUalumnus, that is an incredibly long answer that, unfortunately, does not address my question. My question is a very scientific one, and thus requires reproducable and verifiable results. Since your answer provided no data, there is nothing to verify. So:

How is the global climate model that produces the "hockey stick" verified, validated, and accredited?

How is temperature data from the past 2000 years validated?

Answer 1

Check out this website of the EPA, it has lot of scientificdata and will answer all your questions:

Answer 2

The world is a dynamic place. Ever changing; always will be. That is the cause of the theoretical increase in temperature, if there is one. I don't care how far back mankind THINKS he can see, we are still looking at a mere blink in the life of the planet as far as having recorded temperatures. And, even then, the recordings are only from a relatively few places. The fear mongers of the world have everyone in an uproar! I would be afraid if the average temperatures DIDN'T seem to be changing! They HAVE to change and the causes and meanings of the changes are anyone's guess. But for sure, you will see the self-proclaimed experts running around shrieking about the sky falling and, meanwhile life goes on; yet constantly changing. Will things be the same 50 years from now? Absolutely not!!! How could they? Nothing in nature is static! Can we force it to be unchanging? Not a chance in hell! Should we even try? I think not but there's an immense global industry surrounding the idea that we should and willing to sell you whatever you want in order to make you feel good about yourself and your personal battle to stop the earth from spinning. (This is the generic "you" and not YOU specifically ;) ) Might the changing global environment cause mankind some difficulties in the future, whether near or far? It is very likely, go ask the dinosaurs what nature can do to a group.

Answer 3

The main contributor to the greenhouse effect is water vapor in the air. Then carbon dioxide, some natural, some man made. This is easily proven. You measure the levels of the gases in the air and calculate the warming effect.

There are many causes of changes to the Earth's climate, such as the sun, etc. But man made CO2 is causing _excess_ greenhouse effect (also known as "global warming") that is unnatural and changing the climate unusually fast. This will flood coasts and disrupt agriculture. It's the combination of climate change and our somewhat vulnerable technological society that is the problem.

There are a variety of indirect means of estimating temperature. They are imprecise but good enough to demonstrate that man made excess greenhouse effect ("global warming") is real, and a problem.

Climate models are verified by publishing them in journal articles so that other scientists can evaluate them.

Answer 4

if you knew how science works, you wouldn't have to ask most of your questions.

such as who validates the climate models? it is done by consensus of the scientific community like most theories are. if two different labs come up with entirely different systems, and they both show similar readings, its a pretty could bet things are occurring relatively close to the model. then when you have a third, that is entirely different, it pretty much starts decreasing any notion that they are guessing.

many of the other things you have asked appears as if you are trying to find some way to invalidate global climate change by asking for percentages that you know couldn't be derived without averaging, ir without counting every molecule on the planet.
so here is a website yo can look up those myths.
http://www.undoit.org/what_is_gb_myth.cfm

what percentage of energy produced by the sun warms the hood of your car?
there is no possible way to answer hat question, but it still happens doesn't it?

Answer 5

My name is Rafael Lomena. I write from Alicante (Spain). I am independent investigator on the Accelerated Global Heating and want to share with all something that can turn out from interest to fight this phenomenon.
I believe that the main cause of the Accelerated Global Heating is in the great and increasing forest fires that are whipping to the planet in the last years.
My complete report is in: http://inicia.es/de/rlv/clim.htm
If they do not understand the Spanish they can use the automatic translator that will find in the main page of site:
http://inicia.es/de/rlv
Thanks to all.
(* This message has been translated with a translation software)

Answer 6

It's pretty simple really. CO2 lets visible light pass through it but it's not quite as transparent for infrared waves (heat). Sunlight hits the earth, then radiates away as infrared waves. CO2 blocks those waves from escaping into space, keeping them here on earth. More heat on earth = a warmer earth, thus you get global warming.

Answer 7

The dryness directly made by human activities

Answer 8

Do your part to slow global warming. Plant trees at http://CarbonBankUSA.com

Answer 9

...a fervent desire to regain power in the house and senate.

Answer 10

One cause is the methane gasses given off to raise animals for meat on today's factory farms.

Global warming poses one of the most serious threats to the global environment ever faced in human history. Yet by focusing entirely on carbon dioxide emissions, major environmental organizations have failed to account for published data showing that other gases are the main culprits behind the global warming we see today. As a result, they are neglecting what might be the most effective strategy for reducing global warming in our lifetimes: advocating a vegetarian diet.

The environmental community rightly recognizes global warming as one of the gravest threats to the planet. Global temperatures are already higher than they’ve ever been in at least the past millennium, and the increase is accelerating even faster than scientists had predicted. The expected consequences include coastal flooding, increases in extreme weather, spreading disease, and mass extinctions.

Unfortunately, the environmental community has focused its efforts almost exclusively on abating carbon dioxide (CO2) emissions. Domestic legislative efforts concentrate on raising fuel economy standards, capping CO2 emissions from power plants, and investing in alternative energy sources. Recommendations to consumers also focus on CO2: buy fuel-efficient cars and appliances, and minimize their use. ,

This is a serious miscalculation. Data published by Dr. James Hansen and others show that CO2 emissions are not the main cause of observed atmospheric warming. Though this may sound like the work of global warming skeptics, it isn’t: Hansen is Director of NASA’s Goddard Institute for Space Studies who has been called “a grandfather of the global warming theory.” He is a longtime supporter of action against global warming, cited by Al Gore and often quoted by environmental organizations, who has argued against skeptics for subverting the scientific process. His results are generally accepted by global warming experts, including bigwigs like Dr. James McCarthy, co-chair of the International Panel on Climate Change’s Working Group II.

The focus solely on CO2 is fueled in part by misconceptions. It’s true that human activity produces vastly more CO2 than all other greenhouse gases put together. However, this does not mean it is responsible for most of the earth’s warming. Many other greenhouse gases trap heat far more powerfully than CO2, some of them tens of thousands of times more powerfully. When taking into account various gases’ global warming potential—defined as the amount of actual warming a gas will produce over the next one hundred years—it turns out that gases other than CO2 make up most of the global warming problem.

Even this overstates the effect of CO2, because the primary sources of these emissions—cars and power plants—also produce aerosols. Aerosols actually have a cooling effect on global temperatures, and the magnitude of this cooling approximately cancels out the warming effect of CO2. The surprising result is that sources of CO2 emissions are having roughly zero effect on global temperatures in the near-term!

This result is not widely known in the environmental community, due to a fear that polluting industries will use it to excuse their greenhouse gas emissions. For example, the Union of Concerned Scientists had the data reviewed by other climate experts, who affirmed Hansen’s conclusions. However, the organization also cited climate contrarians’ misuse of the data to argue against curbs in CO2. This contrarian spin cannot be justified.

While CO2 may have little influence in the near-term, reductions remains critical for containing climate change in the long run. Aerosols are short-lived, settling out of the air after a few months, while CO2 continues to heat the atmosphere for decades to centuries. Moreover, we cannot assume that aerosol emissions will keep pace with increases in CO2 emissions. If we fail start dealing with CO2 today, it will be too late down the road when the emissions catch up with us.

Nevertheless, the fact remains that sources of non-CO2 greenhouse gases are responsible for virtually all the global warming we’re seeing, and all the global warming we are going to see for the next fifty years. If we wish to curb global warming over the coming half century, we must look at strategies to address non-CO2 emissions. The strategy with the most impact is vegetarianism.


By far the most important non-CO2 greenhouse gas is methane, and the number one source of methane worldwide is animal agriculture.

Methane is responsible for nearly as much global warming as all other non-CO2 greenhouse gases put together. Methane is 21 times more powerful a greenhouse gas than CO2. While atmospheric concentrations of CO2 have risen by about 31% since pre-industrial times, methane concentrations have more than doubled. Whereas human sources of CO2 amount to just 3% of natural emissions, human sources produce one and a half times as much methane as all natural sources. In fact, the effect of our methane emissions may be compounded as methane-induced warming in turn stimulates microbial decay of organic matter in wetlands—the primary natural source of methane.

With methane emissions causing nearly half of the planet’s human-induced warming, methane reduction must be a priority. Methane is produced by a number of sources, including coal mining and landfills—but the number one source worldwide is animal agriculture. Animal agriculture produces more than 100 million tons of methane a year. And this source is on the rise: global meat consumption has increased fivefold in the past fifty years, and shows little sign of abating. About 85% of this methane is produced in the digestive processes of livestock, and while a single cow releases a relatively small amount of methane, the collective effect on the environment of the hundreds of millions of livestock animals worldwide is enormous. An additional 15% of animal agricultural methane emissions are released from the massive “lagoons” used to store untreated farm animal waste, and already a target of environmentalists’ for their role as the number one source of water pollution in the U.S.

The conclusion is simple: arguably the best way to reduce global warming in our lifetimes is to reduce or eliminate our consumption of animal products. Simply by going vegetarian (or, strictly speaking, vegan), , , we can eliminate one of the major sources of emissions of methane, the greenhouse gas responsible for almost half of the global warming impacting the planet today.


In addition to having the advantage of immediately reducing global warming, a shift away from methane-emitting food sources is much easier than cutting carbon dioxide.

First, there is no limit to reductions in this source of greenhouse gas that can be achieved through vegetarian diet. In principle, even 100% reduction could be achieved with little negative impact. In contrast, similar cuts in carbon dioxide are impossible without devastating effects on the economy. Even the most ambitious carbon dioxide reduction strategies fall short of cutting emissions by half.

Second, shifts in diet lower greenhouse gas emissions much more quickly than shifts away from the fossil fuel burning technologies that emit carbon dioxide. The turnover rate for most ruminant farm animals is one or two years, so that decreases in meat consumption would result in almost immediate drops in methane emissions. The turnover rate for cars and power plants, on the other hand, can be decades. Even if cheap, zero-emission fuel sources were available today, they would take many years to build and slowly replace the massive infrastructure our economy depends upon today.

Similarly, unlike carbon dioxide which can remain in the air for more than a century, methane cycles out of the atmosphere in just eight years, so that lower methane emissions quickly translate to cooling of the earth.

Third, efforts to cut carbon dioxide involve fighting powerful and wealthy business interests like the auto and oil industries. Environmental groups have been lobbying for years to make fuel-efficient SUVs available or phase out power plants that don’t meet modern environmental standards without success. At the same time, vegetarian foods are readily available, and cuts in agricultural methane emissions are achievable at every meal.

Also, polls show that concern about global warming is widespread, and environmental activists often feel helpless to do anything about it. Unless they happen to be buying a car or major appliance, most people wanting to make a difference are given little to do aside from writing their legislators and turning off their lights. Reducing or eliminating meat consumption is something concerned citizens can do every day to help the planet.

Finally, it is worth noting that reductions in this source of greenhouse gas have many beneficial side effects for the environment. Less methane results in less tropospheric ozone, a pollutant damaging to human health and agriculture. Moreover, the same factory farms responsible for these methane emissions also use up most of the country’s water supply, and denude most of its wilderness for rangeland and growing feed. Creating rangeland to feed western nations’ growing appetite for meat has been a major source of deforestation and desertification in third world countries. Factory farm waste lagoons are a leading source of water pollution in the U.S. Indeed, because of animal agriculture’s high demand for fossil fuels, the average American diet is far more CO2-polluting than a plant-based one.