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Some basic, empirical evidence in favor of AGW

I've been thinking about doing another one more specifically about the greenhouse effect and how we can tell the difference between greenhouse warming and solar warming.
Solar is tricky. There are several Cycles. Sunspots is one and other things such as small distance variations between sun and earth.
There's another solar cycle (I have to refresh on) that's 56/57 years; an 18/19/19 one.

The Greenhouse Gas effect effect has been persistent and growing with CO2 (the 200 year graph is powerfully correlative) and is longer than most of the known solar effects.

I haven't seen much published on the increasing Methane either. And Methane is 20x more powerful than CO2 as a Greenhouse gas.
There's also a big snowball/geometric/exponential effect with Methane.
As it warms, the Oceans release more- as do the undeniably melting Tundra belts.

Alot of work to do.
 
Most of the OP I've already seen many times. What I didn't see was repudiation of the fact that, since CO2 makes up such a tiny portion of greenhouse gasses overall (95% of which is water vapor), humans activity accounts for less than half of 1% of greenhouse gasses in the atmosphere. Maybe there's a case to be made that this is all it takes, but I have yet to see that case be made.

I don't doubt that human activity is causing the globe to get warmer... by somewhere between .001 and 1.5 degrees C. The question is how much within that scale.

Thats is the crux of the matter. The amount kicked out by humans and the amount kicked out by the earth.

Keep in mind that CO2 levels were much higher in the past and the earth didn't cook. Now the apocalyptos are screaming the year 3000 we will turn into a cinder. They reached out far enough since they took such a battering when their more recent predictions didn't pan out.

And CO2 is a building block of life and yet the EPA says it is a pollutant. I have a problem with that.
 
Solar is tricky. There are several Cycles. Sunspots is one and other things such as small distance variations between sun and earth.
There's another solar cycle (I have to refresh on) that's 56/57 years; an 18/19/19 one.

The Greenhouse Gas effect effect has been persistent and growing with CO2 (the 200 year graph is powerfully correlative) and is longer than most of the known solar effects.

I haven't seen much published on the increasing Methane either. And Methane is 20x more powerful than CO2 as a Greenhouse gas.
There's also a big snowball/geometric/exponential effect with Methane.
As it warms, the Oceans release more- as do the undeniably melting Tundra belts.

Alot of work to do.

There are patterns to the warming that are consistent with an increasing greenhouse effect but inconsistent with increasing solar output! :prof
Methane is much more powerful by weight, certainly, but it's also of much lower quantity. It certainly plays a role, I can't remember what the exact percentage of radiative forcing was calculated to be from methane but it was a noticeable percentage of the whole. It may play a larger role in the future, apparently there are vast quantities of methane trapped in permafrosted bogs which is starting to become not-so-perma-frost.

Thats is the crux of the matter. The amount kicked out by humans and the amount kicked out by the earth.

Keep in mind that CO2 levels were much higher in the past and the earth didn't cook. Now the apocalyptos are screaming the year 3000 we will turn into a cinder. They reached out far enough since they took such a battering when their more recent predictions didn't pan out.

And CO2 is a building block of life and yet the EPA says it is a pollutant. I have a problem with that.

Thing is, we can actually tell the difference. Fossil fuels have a different isotope ratio of C13/C12 versus natural emissions. (like, say, breathing) Measuring this change in isotope ratios in the atmosphere shows that the "new" CO2 (the increase since the industrial revolution) is primarily coming from us.

As for past CO2 levels, you have to remember that there were other factors involved too, just like always. In the very distant past, the sun's output was lower, so you could have lower temperatures even with higher CO2 levels. Continental configuration, orbital mechanics, supervolcano eruptions, giant asteroids, all play a part and have to be accounted for.

I'd like a source on your "cinder" prediction. It's best to get these predictions straight from papers published in scientific journals and not news articles. Journalists filter what they understand, and they understand very little...
 
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There are patterns to the warming that are consistent with an increasing greenhouse effect but inconsistent with increasing solar output! :prof:
Exactly. Solar effects have waxed and waned but the 'Greenhouse graph' persists with it's correlations to temperature increase.
 
Exactly. Solar effects have waxed and waned but the 'Greenhouse graph' persists with it's correlations to temperature increase.

It even gets more detailed than that. Not only has the warming not correlated well to solar activity as a global average, but the pattern of warming we see matches the greenhouse effect. Nights warming faster than days, winters warming faster than summer, and lower atmosphere warming while upper cools. None of these would be expected from an increase in total solar output.
 
A little "light" science from chirpy Glaswegian Professor Iain Stewart and Alaskan methane expert.

 
A little "light" science from chirpy Glaswegian Professor Iain Stewart and Alaskan methane expert.



OH GOD THE ACCENT WHYYYYY

Sure you can't find another one? :D
 
That's all well and good, but it doesn't explain why glaciers have been melting since the early 1700's.

What does explain why the glaciers have been melting for centuries is the eliptical movement of the Earth around the Sun. As the gravitational forces that change the Earth's path from circular to eliptical tug on the crust of the Earth, magma makes its way from the center to the surface. When the magma hits pockets of methite (solid methane) it melts the methite and methane rises into the atmosphere. This is, in part, why the Earth is warming.
 
That's all well and good, but it doesn't explain why glaciers have been melting since the early 1700's.

What does explain why the glaciers have been melting for centuries is the eliptical movement of the Earth around the Sun. As the gravitational forces that change the Earth's path from circular to eliptical tug on the crust of the Earth, magma makes its way from the center to the surface. When the magma hits pockets of methite (solid methane) it melts the methite and methane rises into the atmosphere. This is, in part, why the Earth is warming.

Milankovitch cycles occur over thousands of years. Yes, they're a factor, but the current warming trend is too fast to be explained by that alone. Solar output also rose slowly until about 1950, which accounts for another piece. How about the rest?

As for the methane, methane levels have not risen in this time period except for the amount that is consistent with human activity. Not much methane has been added by nature. (although certainly not zero)
 
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Milankovitch cycles occur over thousands of years. Yes, they're a factor, but the current warming trend is too fast to be explained by that alone. Solar output also rose slowly until about 1950, which accounts for another piece. How about the rest?

As for the methane, methane levels have not risen in this time period except for the amount that is consistent with human activity. Not much methane has been added by nature. (although certainly not zero)

Well, for one, your premise is wrong. The latest warming trend has been anything but fast. In fact, it is the slowest in the history of the world, as evidenced by the following graph:

2365743345_06bd439344_z.jpg
 
Well, for one, your premise is wrong. The latest warming trend has been anything but fast. In fact, it is the slowest in the history of the world, as evidenced by the following graph:

2365743345_06bd439344_z.jpg

... this chart spans billions of years and is completely useless for looking at a 5-century timeframe or even 50 century timeframe.
 
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... this chart spans billions of years and is completely useless for looking at a 5-century timeframe.

What is completely useless is looking at 100 years and proclaiming a trend that is unnatural when there are billions of years of data showing to the contrary.
 
What is completely useless is looking at 100 years and proclaiming a trend that is unnatural when there are billions of years of data showing to the contrary.

Well, first off this "slowest in history" thing of yours is totally wrong. The reason your chart doesn't prove what you think it proves is because the enormous scale of that chart completely masks the temperature trends we're talking about.
Next, just looking at temperature trends and declaring them to be natural or not based solely on the rate or magnitude of change is also overly simplified. It's not how it works. Nobody looked at the temperatures over the last century and decided it was manmade purely because the temperature changed.

The cause of the change is important. "It's natural" is not an answer. So, you said you had part of it. What's the rest? What is the physical mechanism that makes up the gap?
 
Well, first off this "slowest in history" thing of yours is totally wrong. The reason your chart doesn't prove what you think it proves is because the enormous scale of that chart completely masks the temperature trends we're talking about.
Next, just looking at temperature trends and declaring them to be natural or not based solely on the rate or magnitude of change is also overly simplified. It's not how it works. Nobody looked at the temperatures over the last century and decided it was manmade purely because the temperature changed.

The cause of the change is important. "It's natural" is not an answer. So, you said you had part of it. What's the rest? What is the physical mechanism that makes up the gap?

So what if the source of the temp change is correlated to greenhouse effects and that it can be shown to be caused by man's use of fossil fuels? The graph shows millenia of time for temp and it's scale is 10 degrees. You are talking about at most 300 years of data and a temp change of 0.2 degrees. Predictions from that amount of data are highly dubious, especially since concrete temp measurements are only in the past what 100 years? Other derived sources of temp are not as reliable for producing average temp. Additionally, average global temp is a ridiculous measurement.
 
So what if the source of the temp change is correlated to greenhouse effects and that it can be shown to be caused by man's use of fossil fuels? The graph shows millenia of time for temp and it's scale is 10 degrees. You are talking about at most 300 years of data and a temp change of 0.2 degrees. Predictions from that amount of data are highly dubious, especially since concrete temp measurements are only in the past what 100 years? Other derived sources of temp are not as reliable for producing average temp. Additionally, average global temp is a ridiculous measurement.

Well, no, global average temperature is not a ridiculous measurement for trying to determine whether the planet is getting warmer. Sorry.

Next, it's like .7 degrees in ~150 years.

Finally, temperature projections are not simply derived from looking at past temperature data. It wouldn't take decades of research to accomplish that, just two hours and a spreadsheet.

edit: Even more finally, just because the planet has fluctuated +-10 degrees in the past doesn't mean doing so is particularly beneficial to homo sapien.
 
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Well, no, global average temperature is not a ridiculous measurement for trying to determine whether the planet is getting warmer. Sorry.

Sure it is. You are averaging over space and time. Earth's temperature fluctuates in both space and time. In other words, the heat held by the earth changes. Using such an average to declare whether the earth is overall warming or cooling is meaningless. More detailed data such as the seasonal temps for different regions of the earth would give a better picture of change in heat.

Next, it's like .7 degrees in ~150 years.

link?

Finally, temperature projections are not simply derived from looking at past temperature data. It wouldn't take decades of research to accomplish that, just two hours and a spreadsheet.

What is the margin of error in the predictions?

edit: Even more finally, just because the planet has fluctuated +-10 degrees in the past doesn't mean doing so is particularly beneficial to homo sapien.

Yet homo sapien survived an ice age. Don't see why we wouldn't survive warming, when it does go +10 C. How long in the predictions until that happens? We will run out of fossil fuels before then anyways and have to find alternate energy sources. No need to place restrictions on economic activity at this time.
 
Milankovitch cycles occur over thousands of years. Yes, they're a factor, but the current warming trend is too fast to be explained by that alone. Solar output also rose slowly until about 1950, which accounts for another piece. How about the rest?
Glacier Melt rates have Noticable quickened since the beginning of the Industrial Revolution/CO2 output spurt. And increased noticeably again in the last 30-50 years.

Retreat of the Gangotri Glacier : Image of the Day
Many scientists regard receding glaciers as a symptom of global climate change. While certain types of glaciers—such as surge glaciers and tidewater glaciers—are actually expanding, there are many areas where scientists report glaciers are wasting away and that climate change is the culprit.
For instance, 150 years ago there were 147 glaciers in Glacier National Park. Today, only 37 glaciers remain, and scientists say they will likely completely melt by the year 2030.
Similarly, glaciers all across the Alps are retreating and disappearing every year.
[......]

gangotri_ast_2001252.jpg


The false-color image above shows the Gangotri Glacier, situated in the Uttarkashi District of Garhwal Himalaya. Currently 30.2 km long and between 0.5 and 2.5 km wide, Gangotri glacier is one of the largest in the Himalaya. Gangotri has been receding since 1780, although studies show its retreat quickened after 1971...... Over the last 25 years, Gangotri glacier has retreated more than 850 meters, with a recession of 76 meters from 1996 to 1999 alone.
Gangotri, which waters half a billion people down the Ganges, is temporarily providing more water than historic norms helping the downstream hoards.
However, the melting will eventually lead to less and less water and perhaps even an end to the Holy River itself.
And that was 2001. You can add a few hundred meters retreat since that photo,
Increasing rate of melting noticeable, and blowing away melting rates of earlier centuries, even half centuries, maybe decades.


Environment and Geology: Glacier melting in Himalayas may bring devastating floods in north Bihar plains of India.
"...A recent study by the Indian Space Research Organization, using satellite imaging to gauge the changes to 466 glaciers, has found more than a 20% reduction in size between 1962 and 2001, with bigger glaciers breaking into smaller pieces, each one retreating faster than its parent. A separate study found the Parbati glacier, one of the largest in the area, to be retreating by 52 meters a year during the 1990s. Another glacier that Dobhal has tracked, known as Dokriani, lost 20% of its size in three decades. Between 1991 and 1995, its snout inched back almost 17 meters each year.

Even the Himalayas have grown measurably warmer. A recent study found that mean air temperature in the northwestern Himalayan range had risen by 2.2 degrees Celsius (4 degrees Fahrenheit) in the last two decades, a rate considerably higher than the rate of increase over the last 100 years.

The loss of these glaciers would have a tremendous impact on the ecosystem of the region. With the retreat of glaciers in the Himalayas, a number of glacial lakes have been created. A growing concern is the potential for Glacial Lake Outburst Floods—researchers estimate 20 glacial lakes in Nepal and 24 in Bhutan pose hazards to human populations...
 
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So what if the source of the temp change is correlated to greenhouse effects and that it can be shown to be caused by man's use of fossil fuels? The graph shows millenia of time for temp and it's scale is 10 degrees. You are talking about at most 300 years of data and a temp change of 0.2 degrees. Predictions from that amount of data are highly dubious, especially since concrete temp measurements are only in the past what 100 years? Other derived sources of temp are not as reliable for producing average temp. Additionally, average global temp is a ridiculous measurement.

Don't you get it???

Long-term trends means : Long enough to make the case for AGW, but not so long as to show that the temperatures are not unprecedented, ie : NOT AGW
 
To those who issues with my year 3000 wail of doom, follow the link.

Global Warming: Dire Prediction for the Year 3000 - Yahoo! News

OMG!!! We gotta send our global warming tax to Al Gore so that he can fix it.... quick. I'M SCARED!!!

Honestly, 'the earth is doomed'... It's Co2 killing polar bears... ooh should stop taking hot showers... think of the people in the year 3000... or maybe we should all stop having babies so that there won't be any people left in the year 3000 to be hurt by global warming.

Give me a break...
 
To those who issues with my year 3000 wail of doom, follow the link.

Global Warming: Dire Prediction for the Year 3000 - Yahoo! News

Nothing approaching the word "cinder" appears in that Yahoo article.

Don't you get it???

Long-term trends means : Long enough to make the case for AGW, but not so long as to show that the temperatures are not unprecedented, ie : NOT AGW

I don't think you understand that absolute temperature isn't the concern, it's rate of change and the impact that will have on a very particular set of species. Namely, the ones we eat.

Dinosaurs saw a rapid change in temperature. It did not go well for them. (then, later, also an asteroid. that went worse)
 
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Posting 'Year 3000' disaster REALLY misses the point/mocks infinitely closer Catastrophe/s.
Again on the Gangotri Glacier/Ganges and other Himalayan Glaciers which feed a Billion People.

http://www.washingtonpost.com/wp-dyn/content/article/2007/06/16/AR2007061600461.html
"...The Himalayan source of Hinduism's holiest river, they say, is drying up.

In this 3,000-year-old city known as the Jerusalem of India for its intense religious devotion, climate change could throw into turmoil something many devout Hindus thought was immutable: their most intimate religious traditions. The Gangotri glacier, which provides up to 70% of the water of the Ganges during the dry summer months, is shrinking at a rate of 40 yards a year, nearly twice as fast as two decades ago, scientists say.

"This may be the first place on Earth where global warming could hurt our very religion. We are becoming an endangered species of Hindus,"
said Veer Bhadra Mishra, an engineer and director of the Varanasi-based Sankat Mochan Foundation, an organization that advocates for the preservation of the Ganges. "The melting glaciers are a terrible thing. We have to ask ourselves, who are the custodians of our culture if we can't even help our beloved Ganga?"

Environmental groups such as Mishra's have long focused on pollution of the Ganges. More than 100 cities and countless villages are situated along the 1,568-mile river, which stretches from the foothills of the Himalayas to the Bay of Bengal, and few of them have sewage treatment plants.

But recent reports by scientists say the Ganges is under even greater threat from Global Warming. According to a U.N. climate report, the Himalayan glaciers that are the sources of the Ganges could disappear by 2030 as temperatures rise.

The shrinking glaciers also threaten Asia's supply of fresh water.
The World Wildlife Fund in March listed the Ganges among the world's 10 most endangered rivers. In India, the river provides more than 500 million people with water for drinking and farming.

The immediate effect of glacier recession is a short-lived surplus of water. But eventually the supply runs out, and experts predict that the Ganges eventually will become a seasonal river, largely dependent on monsoon rains. ...
"Year 3000"?

The above could be app 20 years away. 2030.
 
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Sure it is. You are averaging over space and time. Earth's temperature fluctuates in both space and time. In other words, the heat held by the earth changes. Using such an average to declare whether the earth is overall warming or cooling is meaningless. More detailed data such as the seasonal temps for different regions of the earth would give a better picture of change in heat.
Well, they do the seasonal thing too. Monthly also. And by region... But your premise is wrong. We're looking at the whole planet and we want to know if its getting warmer. What better dataset is there than ALL of the data?


In the OP.

What is the margin of error in the predictions?
Depends on the model and where you are in the model, but from what I've seen usually .3-.4 degrees from the lower end of the 95% range to the upper end. (95% range meaning 95% of the model runs fall in this range, they run each model hundreds of times) I think the range also gets larger when you go farther into the future, for reasons that are probably obvious. Climate is highly variable and those variables will amplify over time.

Yet homo sapien survived an ice age. Don't see why we wouldn't survive warming, when it does go +10 C. How long in the predictions until that happens? We will run out of fossil fuels before then anyways and have to find alternate energy sources. No need to place restrictions on economic activity at this time.
Despite what the skeptic crowd will tell you, nobody credible actually thinks we're at risk of extinction. A main issue is that animals and plants have a hard time adapting to rapid changes in temperature. (in either direction) Since we rather enjoy eating plants and animals, this is problematic for us. Namely, various primary food crops are expected to decrease in yield because of warming temperatures. Another thing that skeptics will tell you is that hey, Co2 is necessary for life and plants actually grow faster when you increase it!
Yes, they do. But when you also increase temperature, increase instances of extreme precipitation events, increase instances of heat waves, and account for the fact that weeds respond more positively to CO2 than crops, overall the USDA expects that crop yields will decrease noticeably even with a 1 degree C change in global average temperture. (may not seem like much, but think about how much energy it takes to heat the entire planet by that amount, and that's the amount of extra energy floating around)
 
Well, they do the seasonal thing too. Monthly also. And by region... But your premise is wrong. We're looking at the whole planet and we want to know if its getting warmer. What better dataset is there than ALL of the data?

What is the average Winter temperature? Going up or down? By how much? Spring? Summer? Fall? What is the South American temperature? Going up or down? Averaging over the whole planet over the whole year ignores ALL of the data just by averaging. It is like the difference between computing the area under a curve by difference equations or using calculus.

In the OP.

Nope. You'll have to point it out specifically.

Depends on the model and where you are in the model, but from what I've seen usually .3-.4 degrees from the lower end of the 95% range to the upper end. (95% range meaning 95% of the model runs fall in this range, they run each model hundreds of times) I think the range also gets larger when you go farther into the future, for reasons that are probably obvious. Climate is highly variable and those variables will amplify over time.

Right, two standard deviations. .3-.4 degrees of margin on a .7 degree change is HUGE. It definitely calls into question the pertinence of the mean. Of course it is even larger as you project into the future. As reliable as predicting the weather, right?

Despite what the skeptic crowd will tell you, nobody credible actually thinks we're at risk of extinction. A main issue is that animals and plants have a hard time adapting to rapid changes in temperature. (in either direction) Since we rather enjoy eating plants and animals, this is problematic for us. Namely, various primary food crops are expected to decrease in yield because of warming temperatures. Another thing that skeptics will tell you is that hey, Co2 is necessary for life and plants actually grow faster when you increase it!
Yes, they do. But when you also increase temperature, increase instances of extreme precipitation events, increase instances of heat waves, and account for the fact that weeds respond more positively to CO2 than crops, overall the USDA expects that crop yields will decrease noticeably even with a 1 degree C change in global average temperture. (may not seem like much, but think about how much energy it takes to heat the entire planet by that amount, and that's the amount of extra energy floating around)

I am much, much, much more concerned about the availability of fresh water supplies to grow crops and thus feed livestock, than I am about global warming. I am sure that GM foods can withstand higher temperatures as long as the water supply is not over-taxed.
 
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What is the average Winter temperature? Going up or down? By how much? Spring? Summer? Fall? What is the South American temperature? Going up or down? Averaging over the whole planet over the whole year ignores ALL of the data just by averaging. It is like the difference between computing the area under a curve by difference equations or using calculus.
No, averaging ensures fair estimates and prevent yokels from saying "Since it's cold in the USA midwest this week, then global warming can't be true." The fallacy we see often.
http://www.debatepolitics.com/envir...-here-proves-global-warming-fake-fallacy.html

The New Normal?: Average Global Temperatures Continue to Rise: Scientific American
2010 may prove to be the hottest year since record keeping began in 1880

This trend reaches back further than a couple of years. There have been exactly zero months, since February 1985, with average temperatures below those for the entire 20th century. (And those numbers are not as dramatic as they could be, because the last 15 years of the 20th century included in this period raised its average temperature, thereby lessening the century-long heat differential.) That streak—304 months and counting—was certainly not broken in June 2010, according to the U.S. National Oceanic and Atmospheric Administration (NOAA). Last month saw average global surface temperatures 0.68 degree Celsius warmer than the 20th-century average of 15.5 degrees C for June—making it the warmest June at ground level since record-keeping began in 1880.

Not only that, June continued another streak—this year, it was the fourth warmest month on record in a row globally, with average combined land and sea surface temperatures for the period at 16.2 degrees C. The high heat in much of Asia and Europe as well as North and South America more than counterbalanced some local cooling in southern China, Scandinavia and the northwestern U.S.—putting 2010 on track to surpass 2005 as the warmest year on record. Even in the higher reaches of the atmosphere—where cooling of the upper levels generally continues thanks to climate change below—June was the second warmest month since satellite record-keeping began in 1978, trailing only 1998.

"Warmer than average global temperatures have become the new normal," says Jay Lawrimore, chief of climate analysis at NOAA's National Climatic Data Center, which tracks these numbers. "The global temperature has increased more than 1 degree Fahrenheit [0.7 degree C] since 1900 and the rate of warming since the late 1970s has been about three times greater than the century-scale trend."..."
 
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