Study: Jet Exhaust Affects Weather

An anonymous submitter writes: "Warp 10 speeds may affect... Ooops, wrong story.. Apparently, jets are affecting the weather and contributing to about a 3 degree daily temperature variation. Even a single degree variation in overall temperature (climate) is significant, but I'm not certain how significant is 3 degrees in local temperatures." We mentioned this before - there was a Wired story - but now their work has been published in Nature and the AP has picked up the story.

Comments

Bah

[delta407]

All the concrete in the airports have been doing this for years. Ever hear of urban heat islands?

don't encourage them

[Alien54]

It must be a slow news day.

This will only encourage the weird science crowd who are looking at the contrails as "chemtrails" and look at the whole thing as an effort to control global warming, or do other mean and nasty things.

Google reveals about 18,000 hits on the word "chemtrails" alone. Have a party.

Four days?

[Kobal]

How can you derive significant results from 4 days of data? Silly...

Re:Four days?

[dragons_flight]

Hmmmm, well if the ocean level continues to change at ~2 mm / yr, then it will only take 1,200 years before the water goes up enough to cover the Miami airport at 8 feet above sea level.

Small Statistical Sample

[DLR]

Ok, let me see if I understand this....

According to most theories the earth is 3.5 billion years old. We (humans) have been measuring the temperature for less than 200 years. 200/3.5X10^12=5.7X19^-8. We are attempting to calculat trends in global warming with .000000057% of the total data? I suspect that any competent statistician would laugh you out of his office if you asked him to attempt to calculate a trend with a sample that small.

Weather, not climate

[JanneM]

This is interesting, but remember that this affects weather (short-term variations over a restricted area), not climate (long-term trends on a large scale). As another poster pointed out, cities and other urban development does the same thing.

More worriesome is that jet exhaust probably contributes proportionally more to the greenhouse effect than the amount of pollutants realeased would indicate, as it tends to be dumped high up, resulting in more greenhous gases ending up in the ozone layer than it would have had it been burned close to the ground.

/Janne

Existence of nuts shouldn't prevent science

[sam_handelman]

Cell phones don't cause brain cancer. Does this mean researching the effect of high voltage power lines is a waste of time?

Lunatics believe that aliens visit earth on a regular basis to indulge their twisted ass fetish. When we look for evidence of martian microbes, are we just encouraging them (lunatics, not martians)?

This contrail weather effect is good science - the deviation they've identified in temperatures is statistically significant. Now, that isn't proof; statistically significant variations do arise by chance, and you can certainly get a stistically significant result that confuses the real causality (Less people Drove around Sep 11th, did that cause a significant local drop in CO2? Is this an incidental effect of overall climate change? So on and so forth.) However, just because it isn't proven, we can't dismiss it either (personally, I think contrails probably do effect the weather,) just because there are loonies who believe something similar.

Re:Hardly science..

[Mr. Slippery]

those results will never get published in any scientific journal...

You didn't even have to RTFA - the write-up itself says, "but now their work has been published in Nature." You know, the well-known scientific journal ?

Let me let you in on something...in investigations of the natural world - you know, that thing outside the lab? - you often don't get to have a formal control group. Cosmologists, for example, don't have a "control" universe to check against. Neither do meterologists have a "control" Earth to check against.

And if you had RTFA, you might see that what they were looking at was not the average temperature, but the temperature swing between day and night.

Saddest thing of all is that your post was modded up.

Jet exhaust?

[Fat Casper]

How about contrails?

I love the "3 days isn't statistically significant" crowd. They had 3 days with no civilian air traffic. They observed military cargo flights leaving contrails that over a few hours turned into very large cloud formations.

Weather satellites observing six separate instances of these contrail to cloud formation growths is significant. There were more, but they spotted six instances where one plane flew through a clear area and made a cloud formation. Thet's pretty clear. Take 3 days without vast airplane formed cloud cover and, using all the other days with the manmade clouds as a control group, you can spot a 3 day blip with temperature variations of 3 degrees celcius more than all the days before and all the days after.

We had a 3 day window with wider variation in temperature extremes. We had a 3 day window with negligible air traffic. We have documented how well one airplane can make cloud cover. I'm not a global warming person or anything, but if it looks like a duck, swims like a duck and quacks like a duck, then you've got an agenda of your own if you won't admit that we've got a duck.

Saying that air travel affects our weather isn't panic or tree hugging, it's observation. We're not going to stop flying. We are affecting things, for good or bad we don't even know. I don't know how we'll be able to tell- that's where this information is insignificant. The effects are obvious, but whether these effects are actually bad is not something we can determine yet, if ever. Who knows, maybe more research on jet propulsion can end up stopping this. different insulation, directed airflow, who knows? Just because we don't fully understand something doesn't mean it doesn't exist. We may not have to, or even want to change anything. We just don't know enough about it yet.

Re:Touching the surface

[ipfwadm]

A more interesting study would be to stop all petroleum based engines for a month (including jets), and measure the impact on the climate...Alas, this will never happen, because people are addicted to their lifestyles.

Are you kidding? You're asking every single person in the world to roll back their technology over 100 years. How would ANYONE get around? It has nothing to do with addiction to lifestyle, it has to do with that technology being necessary for most people's LIVES, since so few people have any alternate means of transportation. Since the advent of the supermarket, corner markets no longer exist (sure, convenience stores exist, but have you ever tried to actually eat a meal from a convenience store that consists of more than chips and beer?). The majority of the population would have a hard time getting to and from a grocery store, typically located several miles from their home. For most people, walking that far would be an all-day proposition, or out of the question entirely. Not many people have a horse and buggy anymore, and a bike that isn't set up to carry a load is woefully inadequate to the task of hauling large quantities of groceries. Not to mention the fact that farmers wouldn't be able to harvest their crops without their petroleum-burning tractors, combines, etc, so even after your little experiment was over, people STILL couldn't eat. Few people would be able to get to work, since few people live within a short distance of their jobs (the car made suburbs possible). Do you consider natural gas- or oil-fired power plants to be petroleum based engines? If so, we wouldn't have much electricity either. In short, the economy would completely shut down, thousands of people would die, and your "interesting study" would have a disastrous effect on the world.

It PREVENTS temperature variation

[j7953]

First, they're not actually talking about exhaust here, they're talking about contrails, i.e. condensed water (clouds).

Second, the contrails, don't contribute to a temperature variation, they prevent it: "the clear skies boosted the temperature swing between daytime highs and nighttime lows by about 3 degrees nationwide."

Third, to all those who say this is laughable statistical analysis, it is not. They studied the weather, not long-term climate changes. And in fact it is well known that on days with a clear sky, it gets hotter during the day and colder during the night. I'm sure everyone of you already noticed that. The clouds prevent the sun from heating up the earth during the day, and during the night, they prevent the heat from radiating into space. The only thing that had not been researched so far was the effect of the (small) amount of clouds that are artificially created by jets every day. Surprisingly, it turns out that these clouds have the same effect that other clouds have.

Relating this to global warming is just speculation. Contrails are basically just clouds, and I don't think reducing variation in temperature between day and night will contribute to or reduce global warming. That just doesn't make sense, it's like saying rainy days contribute to global warming because there are so many clouds. Now I'm pretty sure that jets do contribute to global warming, but that's due to burning fuel, not due to creating contrails -- they could just as well burn the fuel on the ground, causing no contrails at all, and it would contribute to pollution of the air.

Dendracronology and ICE cores

[oliverthered]

ok i probably can't spell Dendracronology but
There have been studies of tree rings (Dendracronology) thousands of years old, the width of the tree ring tells you about the climate at the time it was growing.
So we have measured global tempretures back a few thousand years at least.
Then there's the ICE cores that can also tell you about global climate, they too go back thousands of years.

So you can say that in the past 50-100 years the climate has changed a stastically signifacant amount when compaired to the past 3-4 thousand years

failing that....
Rock strata can tell you somthing about climate going back 10's or hundreds of thousands of years.

Believe what you want

[Mulletproof]

It's you're call who to believe, and as to Bush, it turned out that those were elements of his cabinent who weren't authorized to make the statment, but that part of the story didn't see even half as much press. But don't believe me :p

Read the Abstract

[bellings]

When slashdot selected the same story just three short days ago, they also linked to an NPR story and a blurb on the nature website.

I'll one more, very important, link to the mix. You can read the abstract for free. Reading the paper itself is not free, unless you count going to your local university library for the dead tree copy as free. Before anyone else comments on the science behind this, please at least read the abstract, and hopefully have the knowledge to pass at least one introductory statistics course.

You're confusing your atmospheric problems

[K-Man]

The depletion of the ozone layer is caused by the release of Chlorofluorocarbons (CFC's) used as refrigerants and aerosol container propellants, rather than the release of carbon dioxide through the combustion of fossil fuels, which causes the greenhouse effect. There is little connection between the two problems.

Your right,

[FreeLinux]

This has been scaring the crap out of me for years! I've lost many a nights sleep fretting about the ocean rising, as it is. I don't know what to do but, its obvious that we've got to do something. And do it fast, we only have 1200 years before Miami sinks.

Oh bother.

As usual, no one reads the article

[andyring]

Read the article people! That 3-degree variation ended up LOWERING the temperature by 3 degress on account of air traffic, not raising it. So, if we're all worried about global warming, fly more!

Re:Hardly science..

[Mr. Slippery]

There is a joke non-existing journal eften refered to in the scientific world, it's called "Journal of non-repeatable results",

Do you perchance mean the humorous Journal of Irreproducible Results, which very much exists?

and belive me "Nature" is one such journal.

So Watson and Crick's discovery of the structure of DNA was a "non-repeatable" result? Fascinating.

those results will never get published in any scientific journal!

Nature is a well-respected peer-reviewed scientific journal. So your assertation is simply not true.

As for the rest of your post, I can't find any defintion of "skyes" other than a chain of islands off of Scotland, so I have no idea what you're talking about.

Almost sounds like you're talking about clouds - but of course, the whole fscking point of this research is how contrails affect cloud formation which then affects local climate.

Don't be so short-sighted...

[WIAKywbfatw]

You know, you might laugh about it, but if you lived somewhere where even a slight variation in sea level is of major concern, say Venice or Bangladesh, then I doubt you'd be so flippant about the issue.

(Fact: Venice is sinking and many of its famous piazzas are frequently flooded. Fact: Bangladesh is under constant threat from flooding, which affects millions and kills thousands practically every year in recent history.)

I find it curious that a great number of people who comment on /. stories that have an environmental slant to them have nothing positive to add to the debate and prefer joking about the subject rather than even admit that there might be a serious problem that needs to be addressed.

If there was a small chance that toxic chemicals were seeping into your drinking water then you'd be mad to dismiss it so nonchalantly. If there was a small chance that your car's tyres were defective and could kill you then you'd be mad to ignore that too.

Similarly, if there's a small risk that your actions (together with that of the rest of the civilisation that you live in) was causing major damage to the ecosystem then you'd have to be a complete idiot to ignore the possibility.

Somehow, on /. if not elsewhere, it's fashionable to be worried about the chances of the human race being wiped out by a giant asteroid collision but it's laughable to suggest that we (and countless other species) may be at danger because of our own reckless behaviour.

Re:Don't be so short-sighted...

[dragons_flight]

Forgive me, I agree that global warming is no joking matter, but you could use a better argument.

Venice is a total red herring. The reason Venice is sinking is primarily caused by the depletion (mostly by the mainland) of the aquifer that extends out under the bay and the island. I don't recall whether water usage has changed since identifying the problem, but I do remember that a large portion of the depletion actually resulted from WW2 era industrialization.

Bangledesh flooding might in fact be related to global warming, but the direct cause is increased rainfall (e.g. more/stronger monsoons) in the local river basins.

In neither case is changing global sea levels the main source of their problems. I suspect that there might be some islands that have a bone to pick with sea level change, but at current I don't know of any locales where this is their primary environmental concern.

As for chemicals in drinking water or defective tires, of course there is always a small chance that these things are happening to me. What you probably meant to say was that it would be foolish to ignore it if there was some evidence to suggest it was true. While I've never seen anything particularly bad about my tap water, there certainly is at least some evidence to suggest global warming is happening and is potentially very bad.

Honestly though, I don't think it's "mad" for most people to ignore global warming, because in all reality most people are irrelevant to the debate. Few people have the scientific background to contribute meaningfully to the debate, and even fewer are in the position to make policy decisions that will matter. Sure, it's all well and good that you recycle and turn out the lights in empty rooms, but even if the whole world started doing that it's unlikely to matter as much to global warming as, for instance, if US politicians insisted on a 10% increase in car fuel efficiency.

Maybe you think advocacy matters in setting policy? But even if you and a million of your friends yelled about the dangers of global warming till blue in the face, politicians are only going to do enough to placate you or shut you up, unless you can present a well reasoned, solid, and scientific case to justify the huge expense of actually doing anything significant about global warming. Frankly, I wouldn't want my politicians to spend billions of dollars because the sky MIGHT be falling; I'd want them to be pretty damn sure. Which goes right back to why most people are irrelevant.

Ultimately, what to do about global warming will be addressed in research labs and government offices, and what the average Joe thinks won't matter very much. I suppose the nebulous fear that people feel about global warming does help keep research dollars flowing, but other than that it's pointless anxiety for most people.

Have you forgotten about hijackers?

[MillionthMonkey]

Nevermind that you can make it damn near fool-proof and crash resistant (like nuclear warheads that'll withstand impacts the rest of the airframe won't), environmentalist propaganda would paint pictures of meltdowns in the sky and the scattering of nuclear material everywhere.

Oh please. Even if the reactor is made 100% safe so that a skyscraper impact spreads no radiation, how do you prevent the plane from being hijacked and flown to an "axis of evil" nation that wants to get its hands on the plutonium? A nuclear plane could fly around the world many times without refueling, so this is an issue even for domestic flights. A nuclear-powered commuter flight from Boston to New York would easily be in range of North Korea. How are you going to guarantee that this won't be a problem? With computer-enforcement of no-fly zones? Or by arming pilots?

The tight export controls on a nuclear plane would be just one of the many headaches that an aerospace manufacturer would face, and while those caused by "tree-hugger" sensibilities are among them, there are many others. Ideology aside, safety and nonproliferation are serious problems that need to be addressed in any project of this nature. Nuclear planes are not cost-effective to manufacture. And unlike nuclear submarines, they do not solve any compelling problem that is left unaddressed by their conventional counterpart. Even the military, which comissioned the manufacture of nuclear submarines during the Cold War and was not as affected by "environmental propaganda", never did the same for the nuclear airplane.

Another thing they didn't factor in

[thogard]

The US was at a stand still thoes three days. Auto trafic was much lower as was industrial output (as well as industrial pollution) was down for those three days.

Maybe they didn't measures what they thought they were.

NASA contrail images

[ckedge]

I can't seem to find it now, but I've seen a NASA picture (super high res color) of the Eastern Seaboard that was just COVERED with contrails.

Here's everything that I can find in 5 minutes, it comes close to showing what I saw once. (I swear it was from the Terra satelite, but I can't find it right now)

http://www.wrh.noaa.gov/Flagstaff/science/contrail .htm

http://visibleearth.nasa.gov/cgi-bin/viewrecord?28 69

http://www.wrh.noaa.gov/Flagstaff/science/contrail s040595a.gif

http://visibleearth.nasa.gov/cgi-bin/viewrecord?53 46

http://visibleearth.nasa.gov/cgi-bin/viewrecord?47 43

Ships put out an amazing amount of water vapour, and photos of the Western Seaboard have shown huge numbers of ship generated cloud banks off of San Francisco. Here's one example:

http://visibleearth.nasa.gov/cgi-bin/viewrecord?11 335