An Inconvenient Truth

[Snowguy716]

I looked back a few pages, but couldn't find a thread dealing with this documentary. Please move this post there if one does exist.

I saw this movie for the first time last night, and I was really impressed. I never realized Al Gore was so passionate about this issue. He is no stupid man, and I think he realizes what's going on.

I think the most telling things in the film were these:

1.) Of a 930 article sized sample (10%) of all articles published in journals, etc. over the past 15 years on global warming, 0 of them doubted the scientific consensus that global warming is being caused by an abrupt and unprecedented increase in atmospheric carbon dioxide, put there by humans. At the same time, a sample of 600 articles in the popular press dealing with global warming showed that 53% expressed doubt about anthropocentric climate change. That's quite a discrepancy.

2.) (I had seen this before, but Gore made a staggering case here) Ice cores drilled out of Antarctica's ice cap showing 650,000 years of ice build (like tree rings) trap bubbles of CO2 in the layers, showing how much CO2 was in the atmosphere. In the past 650,000 years (which includes 6 ice ages), the Co2 concentration in the atmosphere never exceeded 300 ppm (parts per million). The concentration recorded in Hawaii in 2005 showed 380 ppm, higher than it has ever been in the past 650,000 by a long shot. It is exptected to reach between 500 and 600 ppm by 2050, significantly higher than has probably been recorded on earth in millions of years.

He then shows a near perfect correlation between CO2 concentration and atmospheric temperature.

Most amazingly, the difference between 200 and 280-300ppm in CO2 concentrations is the difference between having a mild climate in Cleveland, Ohio, and having a mile of ice overhead.

If only a few degrees Celsius means the difference between a balmy summer day and a mile of ice overhead, what will drastic changes have from a more than doubling of CO2 concentration?

Temperatures are expected to rise anywhere from 2.5*C-6*C in the next century. Even the lower projections would mean a 4.5*F rise in temperatures. That translates to a 1*F rise at the equator and a 12*F rise at the poles. We're talking about a north pole that already gets above freezing in the summer. IF there is a 12*F rise in temperatures up there, the polar ice cap will be long gone, which will have a profound impact on species like the Polar bear, and also people that live up there.

A 6*C rise (or an 11*F rise) could mean temperatures warming as much as 20*F at the poles. This would likely trigger an irreversible melting of the Greenland and West Antarctic icecaps. Even if half of each melt, that will raise world sea levels TWENTY feet. Bye bye Manhattan.... Miami... Tampa.. New Orleans... Most of the Netherlands, Bangladesh, Calcutta, Shanghai, most of Beijing...

We're talking about the displacement of over 100 million people.

And this isn't just a far-fetched scare tactic. Scientists have been rather conservative in their projections. They never would have dreamed that the entire Larsen B ice shelf in western Antarctica would break apart and melt. This breaking up has allowed the land based glaciers behind it to speed up rapidly and melt into the sea, which contributes to sea-level rise.

A 6*C rise would render Minnesota's climate much like Kansas'. New York would have weather more attuned to Savannah, Georgia.

This isn't junk science. This is widely accepted by scientists (except those who are funded by oil companies). There is already a largely established warming trend that coincides nicely with rises in CO2 concentrations that we've measured over the past 50 years.

Nothing can really account for the dramatic rise in temperatures except Co2. By all other standards, the '90s should have been a cool decade for planet earth with a major volcanic eruption that altered the climate and oscillations heading into territory that favors a cooler climate in the northern hemisphere. But it wasn't. All 10 of the hottest years in the global record have occured since 1990, and with 2006, that'll be 1991.

Call it "natural cycles" (It's not. Scientists have proven that). Call it exaggerated (It's more likely under-estimated)... come up with whatever excuses and justifications you want (under water volcanos)...

The fact that you can see a dramatic change (much cleaner) in the ice layers on Antarctica within a few years after the U.S passed the Clean Air act is proof in itself that our impact on the planet is profound. And I don't think Jesus will be returning in time to save us.

[nowensone]

This may be a good place to ask a related question, did you Snowguy, or anyone else, read Michael Crichton's book State of Fear? It is fiction, of sorts, but actually casts doubt on the popular theory of global warming more so than it tells a fictional story, and also footnotes nearly every scientific claim in the book with real sources. I did not know quite what to make of it since I keep up on science pretty adamantly, but it is both convincing and doubtful at the same time.

[JDC]

Scientists have tried to warn us, but I think they're tired of being blasphemed by the skeptics (the US government included) so they're just gearing up for a big "We told you so."

[Snowguy716]

This may be a good place to ask a related question, did you Snowguy, or anyone else, read Michael Crichton's book State of Fear? It is fiction, of sorts, but actually casts doubt on the popular theory of global warming more so than it tells a fictional story, and also footnotes nearly every scientific claim in the book with real sources. I did not know quite what to make of it since I keep up on science pretty adamantly, but it is both convincing and doubtful at the same time.

[dimebag1980]

This may be a good place to ask a related question, did you Snowguy, or anyone else, read Michael Crichton's book State of Fear? It is fiction, of sorts, but actually casts doubt on the popular theory of global warming more so than it tells a fictional story, and also footnotes nearly every scientific claim in the book with real sources. I did not know quite what to make of it since I keep up on science pretty adamantly, but it is both convincing and doubtful at the same time.

[nowensone]

I have the book, but have only read parts. One of the big things Crichton relied on were graphs that were often isolated places and only used time periods to suit his argument.

The fact of the matter is, is that when you put it all together on a global level, the trend is always warmer.

I could go on for days giving you "evidence" against global warming and probably have myself believing there was no such thing... but I'm convinced.

Take a look at Mississippi's summer temperatures over the past 110 years. There's been a dramatic cooling (the summers in the south just aren't what they used to be, before about 1958)... the same can be said for Maine, which has a generally cooling climate, overall.

Maine's cooling climate can be attributed to two regional, localized things:

1) Re-forestation. In the past 100 years, much of what was once farm land (poor farm land, at that), has been reforested as people abandoned the farms and moved west. More forests can reduce Co2 in a localized area and also provide more shade on the ground, keeping the temperatures cooler.

2) Trends in the Arctic and North Atlantic Oscillations that keep the jet stream in a zonal west-east pattern. This keeps cold air locked up in the arctic and rather than diving southward like is more typical, they move straight across Canada to the maritime provinces and dip down into northern New England. 1998/99 and 2001/02 are good examples of zonal patterns that keep arctic air locked to the north.

This is why from 1952-1997 Greenland actually had a net cooling of temperatures. When the NAO and AO began to go negative again (after an unusual period of positive values for about 10 years), Greenland warmed up dramatically to record temperatures. While Greenland cooled negligably, the rest of the world kept warming up.

You have to look at the whole picture, though. Crichton does not do that (from what I've read from the book). It should not be discredited as a good book to read though, it should just be kept in the science fiction section.

[Captain Worley]

State of Fear was a great book.

I'm not convinced about global warming, but that's probably because we were told we were headed for an ice age in the 70s. To me, it could go either way, and either way, we'll adapt to it.

I've heard an acre of grass produces more, but I don't know if it is true. The argument I heard was that there is more leaf surface area in an acre of grass.

Maybe that means we shouldn't mow our yards as much!

[runawayjim]

Question - I was recently arguing with someone who claimed that an acre of grass actually creates more oxygen than an acre of forest. It was pretty heated as that just seems ludicrous to me, after all, a single large tree may have more surface area than a field of grass with which to convert CO2 to oxygen, and spread that across an acre... is there any truth to that?

[Snowguy716]

State of Fear was a great book.

I'm not convinced about global warming, but that's probably because we were told we were headed for an ice age in the 70s. To me, it could go either way, and either way, we'll adapt to it.

I've heard an acre of grass produces more, but I don't know if it is true. The argument I heard was that there is more leaf surface area in an acre of grass.

Maybe that means we shouldn't mow our yards as much!

[michaelskis]

I am not saying that Global Warming is or is not happening, or if we are or are not causing it. But I question some of the results.

You mention the trapped bubbles in Ice Cores. What was the Carbon Dioxide level at the place they took the core samples from? Different places with different climates have different levels. As for Hawaii was there a volcanic release any time around when this record was recorded?

Beyond that, everything that you mention is prediction.

Have you watched The Day After Tomorrow? It talks about how global warming can cause global cooling with ocean current shifts.

I do think that we need to do something about the amount of pollution we give off, because I think that it is altering the climate and causing problems.

There was a great line in Men in Black... 1000 years ago, we knew we were the center of the universe, 500 years ago we knew the world was flat...... imagine what we will know tomorrow!

[Snowguy716]

This shows the measurements of CO2 in the atmosphere since measurements were begun at Mauna Loa in the late '50s. The yearly rise and fall of the measurements is caused by the seasons. Since the northern hemisphere has much more land mass than the southern, the northern hemisphere summer actually leads to a net reduction in CO2 in the atmosphere because all of our trees are breathing in the CO2.

The measurements are taken by weather balloon which are sent up into the upper atmosphere, so any volcanic activity would have a very small impact on the measurements. The location was chosen simply because of its remoteness from large human cities (except Honolulu, of course).

This shows the global temperature record since the late 19th century. Notice the sharp upward trends in the early 1900s with the explosion of Europe's and America's population. This peaked in the early 1940s and then sank back as aerosals (So2, CFCs) emissions rose dramatically with agriculture, refrigerators, new cars, etc.

This shows atmospheric SO2 since about the Civil War. The global temperature rose steadily from the late 1880s or so until the 1910s. As SO2 emissions slowed, the temperature began to rise faster. By the 1930s, temperatures were rising quickly. After WWII, emissions skyrocketed, and the earth's temperature began to fall.

Emissions began to slow in the 1960s and '70s and then the earth started warming like crazy. By the early '90s, human emissions of So2 were very low (thanks to international cooperation on limiting emissions.. mostly because SO2 causes ozone to form, which results in smog). As human sulfur dioxide emissions were falling like a rock, Mt. Pinatubo exploded and drove atmospheric levels of So2 way up, which temporarily cooled the climate of the earth (in the northern U.S, the impact was pretty large with a record cold summer in 1992, followed by cool summers in 1993 and 1994).

Since then, atmospheric So2 has fallen down and global temperatures have surged. By 1998 we had reached an unprecidented record (thanks to a record El-Nino) that was most recently broken in 2005. 2006 will be in the top 3 for global temperature.

Scientists had not taken into account the effect of So2 when making predictions of global warming. It is now widely thought that a warming of up to 10*C (18*F) is possible in the next 100 years. That would be catastrophic to the planet. A climate like Dallas at the Canadian border?

We NEED to get cracking on this and reduce Co2 emissions. They should be reduced as close to 0 as soon as is feasible, and we need to start looking for ways to sequester CO2 and store it down where we've taken the oil from.

Simply pumping sulfur dioxide into the atmosphere will not be a solution (although it might be a short term emergency fix).. but Sulfur Dioxide is what is responsible for all that unsightly pollution (smog) and I don't think we want to go down that road.

Edit: So2 is also the main contributor to acid rain. We really DON'T want to go down that road.

[Captain Worley]

THose who are not convinced by the science of global warming (Captain Worley), I urge you to look up the science on the matter. Don't go around believing what politicians and their paid scientists say. Is it not suspect that the same people that are doubting global warming are the same people that live in states with big ties to big oil and receive contributions from these companies?

[Snowguy716]

I just don't see how this:

Resulting in this:

Has been a small impact.

Or I can assume you've read really nothing that I posted.

[runawayjim]

there's a large impact, no doubt... but do we have data from the last time the cooling/warming cycles warmed or cooled? probably not. also, do we know how long the cooling and warming cycles are?

[Snowguy716]

Here, another showing Antarctica's temperature plus the Co2 overlay for hte past 350,000 years or so. There's a strong correlation. Notice that the graph stops at 300ppm for Co2, and we're at 380 right now, which is the vertical blue-green line at the end of the graph going off the charts.

[runawayjim]

Here, another showing Antarctica's temperature plus the Co2 overlay for hte past 350,000 years or so. There's a strong correlation. Notice that the graph stops at 300ppm for Co2, and we're at 380 right now, which is the vertical blue-green line at the end of the graph going off the charts.

[Captain Worley]

Or I can assume you've read really nothing that I posted.

[Snowguy716]

What is causing the current bout of warming then?

Water vapor contributes most of the greenhouse effect on our planet. But CO2 contributes 7*C at pre-industrial levels (280ppm). This is not something scientists have made up.

They have taken into account increased levels of water vapor as a result of rising CO2 (which warms temperatures), which has been responsible for even stronger warming trends in Europe.

Water vapor does not just magically increase, leading to a rise in temperature. Water vapor is an effect of warming that creates a positive feedback loop.

Other greenhouse gases such as methane (CH4) and Nitris Oxide (No2) are much more potent even than CO2. It is thought that with a certain threshhold of warming, the peat bogs in the northern U.S and Canada will begin emitting large amounts of methane (as they start to die or the permafrost begins to melt), leading to a sudden spike in global temperatures. It's been shown to happen in the past.

[Captain Worley]

Nitrous oxide?? Better go after those drag racers!

I think the temperature increase is probably tied to an increase of energy fom the sun.

Like I said, the Earth will warm or cool, and we'll adapt.

[Snowguy716]

Here are the sunspot numbers for the recent past. Note there is a dramatic increase in sunspots during the '20s and '30s, while the planet warmed.

This is thought to have contributed to the warming during that time. The sun, however, kept getting stronger well into the '60s when the planet was actually cooling, and has actually become less active since then despite a very strong warming trend.

Sunspot cycles are said to have the largest variable effect on the planet. During the mid 1600s, almost no sunspots were recorded for a very long time, and this is when the worst of the Little Ice Age occured in Europe, when people could have frost fairs on the Thames in many winters.

Still, while the sun has been the major driver of our climate when greenhouse gases were rather constant, the worldwide temperature fluctuations were small and often regional. (Europe has a humid climate at a northern latitude, more sun meant more water vapor, and more warming... that's why they a strong Medieval Warming period and a Little Ice age while the rest of the world was rather constant).

Scientists just simply can not attribute the rather unprecidented warming of the planet in the past 100 years to changes in energy from the sun, mostly because the latest period of fast warming (1975 or so through today) has occured during a time with rather constant sunspot numbers.

[Captain Worley]

You are quite the weather guru!

[DigitalSky]

I got to finally see this film recently, amazing at how we estimate and then what occurs, it is really eye-opening. Things are changing fast...

[Snowguy716]

Sorry, I don't have a graph and a lengthy explanation for that I just like weather (which is why I could never live in San Diego).

You do bring up a lot of good points, though. It was questions and skepticism like yours that led to the study of water vapor as a greenhouse gas and its recent effect on our climate. It was found that much of Europe's warming is caused by increased humidity.

[Captain Worley]

Snowguy, you've probably seen this site, but here you go:

http://www.planetextinction.com/index.html

[Snowguy716]

Another effect of higher CO2 concentrations completely apart from global warming is changing the PH value of the oceans. As Co2 becomes more prevalent, the oceans become more acidic.

This has the effect of killing plankton and corals. Plankton are one of the most important species in the oceans, as they are the bottom of the food chain.

It is becoming obvious that we should work to reduce our Co2 emissions greatly whether or not it is for the sake of keeping our planet a cool 58*F

Not to mention that while 2-5*C might not sound bad over 100 years, it could have the effect that the Younger Dryas period had.

At the end of the last ice age as the planet warmed up, the massive glacier of North America began to melt. A massive pool of water filled in the middle of the glacier. The Great Lakes are the remnants of this glacier. Sometime, about 12,000 years ago, an ice dam broke in NE Canada and all that cold, fresh water poured into the Atlantic ocean. This halted the North Atlantic Current, a current that pulls warm water to Europe.

It threw Europe back into an ice age in the matter of about 10 years and the northern hemisphere experienced another 1,000 years of ice age conditions.

The worry is that with a new bout of warming, Greenland's icecap could melt. It is thought that this is already happening. The N. Atlantic current has slowed by 30% over the past 7 years and even stopped briefly in November 2004, the first time that had ever happened. Luckily, it started back up again, but if it does stop, Europe could be in for it.

I think about this process we're undergoing as a sputtering engine. It kills but starts itself back up and sputters before finally going out for good.

Scientists think this highly unlikely, but most of their speculations came out before the current stopped for a week.