Why has no scientific paper concluded that more than 35% of the recent warming is due to the Sun?

Question

A Scafetta & West paper used a model to conclude that the Sun may have been responsible for 25-35% of the warming over the past 30 years. As I discuss here, they had to make some highly questionable assumptions to attribute this much to solar influences:

http://answers.yahoo.com/question/index;…

and most studies have attributed just 0-10% of the recent warming to the Sun. I'm not aware of any study which has attributed more than 35% of the warming over the past 30 years to the Sun (and I'm pretty sure if one existed, the skeptics would have made me aware of it).

So let's assume Scafetta&West are right, and one-third of the recent warming has been caused by the Sun. What could have caused the other two-thirds, if not human greenhouse gas emissions?

Will the skeptics admit that at least two-thirds of the recent warming is anthropogenic (say 0.15°C/decade rather than 0.2°C/decade)? If not, what caused it?

Additional Details

Or if the Sun is responsible for more than one-third, why has no scientific study ever come to this conclusion?

Of the first 9 answers, the only one that came close to answering the question said "because it true, DUR!"

Wow.

Ron C - you trot out various disproven theories from time to time. Sometimes it's these climate indices synchronization

http://answers.yahoo.com/question/index;…

Sometimes it's bias in the surface temperature record, sometimes it's low climate sensitivity, etc. etc.

These arguments are all fundamentally flawed. The oscillations don't directly generate heat nor do they have the capacity to retain it.

Answer 1

Best Answer - Chosen by Asker

"Natural cycles!"

The sun's heating does vary with the regular, predictable orbital changes of the earth ("Milankovitch cycles"). We're in a slow cooling trend which began 6000 years ago.

"The sun!"

Here are measurements of the sun's radiation:
http://data.giss.nasa.gov/gistemp/2007/

In October Mike Lockwood of the UK's Rutherford Appleton Laboratory and Claus Froehlich of the World Radiation Center in Switzerland published a paper that concludes:
"Here we show that over the past 20 years, ALL the trends in the Sun that could have had an influence on the Earth's climate have been in the OPPOSITE DIRECTION to that required to explain the observed rise in global mean temperatures."
http://journals.royalsociety.org/content…

So why don't global temperatures follow the sun's influence? Something else must be a much stronger factor in the trend.

Observations of past orbital cycles ("natural cycles" of the sun's warming influence) show that the sun's direct influence exists, but that it cannot fully explain past climate change. There are other major, often stronger factors involved that affect the earth's retention of the heat that the sun delivers. One of those factors is the involvement of carbon-based gasses ("greenhouse gasses") which help the earth trap more of the heat from the sun. The existence of greenhouse gas warming is easily and dramatically demonstrated by the temperature of Venus, which has a much higher concentration of CO2 in its atmosphere.

So we know from measurements that the sun hasn't been increasing in strength for the past few decades, that its major recent trends have been negative, and that current climate trends haven't been following its minor changes in radiation. We can see the temperature on Venus due to greenhouse gases. We know that greenhouse gases on earth were elevated during "natural cycles" in the past that didn't coincide with the timing of the sun's influence.

The Earth's average surface temperature of 15 °C (59 °F) is about 33 °C (59 °F) warmer than it would be without the greenhouse effect.
http://en.wikipedia.org/wiki/Greenhouse_…

Here's how the greenhouse effect works:

"For the Earth's temperature to be in steady state so that the Earth does not rapidly heat or cool, this absorbed solar radiation must be very closely balanced by energy radiated back to space in the infrared wavelengths."

"The visible solar radiation mostly heats the surface, not the atmosphere, whereas most of the infrared radiation escaping to space is emitted from the upper atmosphere, not the surface. The infrared photons emitted by the surface are mostly absorbed in the atmosphere by greenhouse gases and clouds and do not escape directly to space."

Increase the greenhouse gasses, and you increase the heat trapped.

We've recently been able to measure the imbalance between the incoming and outgoing radiation:

Earth’s Energy Out of Balance: The Smoking Gun for Global Warming
http://www.columbia.edu/~jeh1/imbalance_…

"Scientists at Columbia University, NASA, and the Department of Energy have found that the Earth is out of energy balance: the Earth is absorbing more energy from sunlight than it is emitting back to space in the form of heat radiation. This imbalance provides confirmation of global warming theory and a measure of the net forcing that human’s are applying to the Earth by adding greenhouse gases and other pollutants to the Earth’s atmosphere."

Increased radiation from the sun could make the earth warmer, but in a steady state the warmer earth would simply radiate more heat back to space. The key here is the imbalance. Heat is being trapped. The earth is warming. Greenhouse gasses in the atmosphere provide the heat-trapping mechanism, but if they were steady the outgoing radiation would match the sun's radiation. What NASA is saying is that the increase in greenhouse gasses provides the current unbalanced state between the earth's incoming and outgoing energy.

So the sun's influence can be debated (credible papers put its influence as negative), but the measured lack of matching heat radiation means that more of the sun's energy is being trapped, and we know that mechanism to be greenhouse gasses.

Asker's Rating:

Asker's Comment:

Great summary of the science explaining why we know the warming is anthropogenic.

As usual, the skeptics/deniers crumble in the face of scientific evidence. They claim the warming is due to the Sun, but not one single scientific study has come to that conclusion!

Answer 2

people are so focused on carbon dioxide and the polar bears that nobody takes the time to look at natural causes

Answer 3

because it true, DUR!

Answer 4

If you were a scientist you would've just lost any current funding and any possibility of future research grants.

Answer 5

Global Warming. The biggest fear mongering who cares scam ever created. The world has been heating and cooling for millennia. Anyone ever heard of an "Ice Age"

Answer 6

Agree! 20 years ago astronomers wrote about the sun becoming 10,000 degrees hotter and being hot enough to be classified as a white star. As a kid I don't recall such bright nights. The suns refection off of the moon seems much brighter than even 10 years ago.

Answer 7

Hello,

100% of global warming is due to the sun.

The semi-vacuum immediately outside our armosphere is -272 kelvin.

Answer 8

who cares, jesus will be here before the scientists dry up when the earth becomes a desert. it's too bad most people have their noses so far into conspiracy articles to realize that most of it is bullshit to scare us or distract us from war and other things. has it ever occurred to al gore and the rest of those who like looking at the sun and doing scientific equations-- that maybe we're getting these readings now because we are finally equipped with the knowledge to understand them? yes, it's true, most people would rather drive a gas guzzling SUV instead of a battery opperated car that looks like it's from the next generation, but can you blame us when THAT is the message that the American economy is feeding us? Who wants to buy recycled ****, when you can have something else that looks nicer and is more cool.
Let's talk about something more interesting, like how the the government is giving us back tax money to spend on more frivolous crap like plastic and candy.

Answer 9

The Clement changes every year, it always has, its what the earth does. Its -11 degrees here in Iowa not all that warm at all if you ask me! However, pollution is getting worse and we need to start worrying about how clean the air will be when our grandchildren grow up! We can change it in the US but India and China are growing at a crazy amount every day and the more people the more pollution. All of man kind needs to come together and stop this problem. On top of all of this the gas company's have no plans to slow down but they do plan to keep raising prices! Who ever comes up with a none pollutant way to run a car at a descent price is going to be very rich!

Answer 10

Global warming does exist. It has existed in concert with global cooling for millions of years.
Whether it is caused by HUMANS or not is the subject of the debate and the answer that you see depends entirely upon just which alarmist/skeptic report that you read.
The geologic history of Earth seems to indicate that this planet has been much warmer for a much longer period of time than it is currently. The ice core samples indicate that Earth is just NOW emerging from an ice age and should attain its NORMAL average temperature within a few hundred years.
That global warming is indeed driven by the sun is evidenced on the other 7 or maybe 8 planets in our system and, coincidentally by the ice core data.


No, humans did not cause it nor can they stop it.

Source(s):

Adapt or die.

Answer 11

Few will argue that the sun does not go through cycles that increase amount of energy it gives off. The big question is how much of that energy is simple radiated back into space or trapped in Earth's Atmosphere warming plant and slowly eliminating the factors that lead to the first snow flake on Earth.

Answer 12

More ridiculous answers. I've wondered why this forum is full of ignorant denialists. I think it's because informed people already know AGW is happening and don't have a need to come here and gripe about the vast worldwide conspiracy.

Answer 13

Because global warming is caused by man. To the guy who said that it is -272 degrees kelvin you know absolute zero is 0 degrees Kelvin. You probably meant to say -272 degrees Celsius.

Answer 14

I've noticed in other situations that people will cling relentlessly to a sliver that seems to agree with them rather than discard it and go with the log pile that challenges what they want to be true. I think that happens here at Y!A more than in some forums I've seen.

Scientific papers generally submit to peer review. If it doesn't pass the muster on peer review, it doesn't get published. I think that may be why many of the links used to refute the human contribution to global warming are from web-sites that do not undergo peer review.

My answer, then, is that such "science" would be unable to stand up to critical review.

Answer 15

I completely agree with aaronesque

Answer 16

Isnt all the heating of the Earth being caused by the sun? (haha just kidding, I know what is meant).

I have said a lot here, and it is almost proven that global warming is happening, and anthropogenic, and really, to help in your own way to prevent it from getting better, would that hurt your "liberties" that much? If you took liberty in smashing people's heads with a brick, and you were arrested for it, would that hurt the liberty of doing that?

Awwww! you would have to drive a smaller car? That's going to happen anyway, no matter what you say about global warming, and really, I do not know a lot of people who need an SUV, but lots who have them, just to keep up with the neighbors.

I do my part, and global warming is a symptom, and there will be a lot more symptoms if we do not stop pollution.

Answer 17

Because a good part of natural climate variation is from internal climate variability, such as from the PDO and ENSO (El Nino Southern Oscillation). The PDO has a warm phase that can last for 30 or 40 years.

I have answered this type of question for you repeatedly, Dana. I do not understand why you continue to ask it.

Source(s):

http://en.wikipedia.org/wiki/Pacific_dec…

Answer 18

Because it wouldn't make sense for the sun to be responsible for 50% or above of the warming. You don't need to be a scientist to figure this out, you just need common logic. Sun spots (I'm referring to them because they are what skeptics most often bring up) go through 11 year cycles. We've seen thirty straight years of warming. If sunspots were to blame for the dramatic increase in temperature, then why isn't the temperature drastically down in those waxing and waning points of the cycle?

Answer 19

Because the scientists you'll listen too are out to prove that global warming is caused by man. They dismiss the scientists that suggest the sun may be the culprit. You willingly accept any excuse for the warming of other planets, as long as it keeps the theory's of your favorite profs intact. There is a separate theory for the warming of every planet in our solar system. Ours of course is the co2 produced by man. Mars? Axis tilt. Venus? Black surface, and on and on.

Answer 20

I am amazed by people's resistance to accepting the truth about global warming. This isn't an issue that is generally argued in the scientific community. The evidence is easily interpreted by ice samplings and observation. We may have an opportunity to stem the tide of critical changes to our environment, but the effort to control greenhouse gasses doesn't seem remotely interesting to most Americans.

I am also an interested observer of the interactions among people. We are not being very cooperative and seem easily defeated by challenging events. Politicians seem to sense this fact . That's why they are afraid to ROCK THE BOAT by offering difficult solutions to difficult problems (there are no easy solutions). So, we don't have much cooperation or agreement, we don't want to make difficult changes, and we will accept leaders who promise to defend us even though they have no clue how to do it.

Interesting. I have nothing to gain by selling you my ideas. I will be dead by the time much of our country is under water (and that will not be that far from now). But I am disappointed in our country's inability to cope with the issues.