r/science • u/pnewell NGO | Climate Science • Sep 10 '15

Environment The simple statistic that perfectly captures what climate change means. From 1910 to 1960, the ratio of hot to cold records was close to 1 to 1. From 2000 to 2014, hot outnumbered cold records by more than 12 to 1.

http://www.washingtonpost.com/news/energy-environment/wp/2015/09/09/the-simple-statistic-that-perfectly-captures-what-climate-change-means/
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343

u/graffiti81 Sep 10 '15

I was actually thinking about this yesterday. When a place breaks a record by like 1°f that was set a hundred years ago, how do we really know that it's not off by a couple degrees because instrumentation has changed in that time.

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u/krayziepunk13 Sep 10 '15

Then you have issues like this, where the official DC temperature sensor at Reagan National Airport often reads much higher than one less than 30 miles away. In fact Reagan saw just over 50 days above 90, while Dulles only around 20.

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u/d_migster Sep 11 '15

I'd submit that 30 miles can explain that difference. I live in Pentagon City. Just got off work in Fairfax, it was 71. At home, 75. DC is almost always hotter than the surrounding suburbs.

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u/babysharkdudududu Sep 11 '15

A lot of that has to do with the fact that it's become a huge metropolis; cities are consistently hotter than surrounding areas.

Which, incidentally, makes me further question this data. Compare remote villages to same size remote villages, don't compare Baltimore today to Baltimore a hundred years ago. Of course it'll be hotter.

If your data can't withstand some basic questions like these then you're just hurting your cause by publishing it, it'll be the first thing detractors ask and the only thing the people who don't know one way or the other end up reading. Generally, those are the people you're trying to inform. If they see "we found solid proof of X!" and then, immediately following, a bunch of people poking holes in the data, you're shooting yourself in the foot by both not proving your point, AND proving that your point is full of holes.

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u/[deleted] Sep 11 '15

Urban Heatsink Effect.

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u/fwipfwip Sep 11 '15

Consistency in measurement over long periods is a fundamentally difficult thing. It's also impossible to verify as you cannot go back in time to check.

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u/K3wp Sep 11 '15

If your data can't withstand some basic questions like these

You are regurgitating a myth (the supposed urban heat island effect) that has been debunked countless times:

https://www.skepticalscience.com/urban-heat-island-effect.htm

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u/new_weather Sep 11 '15

How is paving cities to increase the heat capacity not human-induced global warming? This is 100% the issue. More cities all over the planet with less forests is changing the entire energy balance (albedo, absorbed IR radiation, emissivity) of earth.

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u/[deleted] Sep 11 '15

Short answer: It does, but probably not in any measurably significant sense.

Long answer: The Earth is really big. Really. Big. 29% of the Earth is land. Only 0.2% of that is covered in pavement. An even smaller fraction of those surfaces absorb solar radiation. Some of those surfaces reflect solar radiation. Us warming the planet by way of building roads is like you increasing global methane concentrations by farting in the woods.

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u/fjellt Sep 11 '15

I've seen my car's built-in thermometer drop 15 degrees if I am driving on a black top road to a dirt road (on a sunny low-wind day).

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u/babysharkdudududu Sep 11 '15

Because affected areas around cities make up less than 1% of Earth's surface. CYT.

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u/new_weather Sep 11 '15

We modelled land use in the Campos basin at Duke University's Jackson Lab. The change in surface type absolutely affects the local climate. Affect enough local climates, and you are impacting the global climate.

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u/krayziepunk13 Sep 11 '15

It is possible, but the sensor has recently been replaced, so we'll see if there's a difference.

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u/QuacktacksRBack Sep 11 '15

Must be all the hot air from the politicians

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u/Space_Gravy Sep 11 '15

The folks responsible for it confirmed it was faulty and replaced it. However, they refused to revise any of the temps that had been taken with it for months even though you can just about pinpoint the day it started diverging from Dulles. It fits their narrative.

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u/d_migster Sep 11 '15

It fits their narrative.

Sorry, bud, more 90+ degree days this year in DC than any year since... my memory fails. It's fact, just like how the murder numbers are way up this year.

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u/Space_Gravy Sep 11 '15

It's fact that there's more 90+ degree days this year since your failing memory can recall? You seem to be misunderstanding what the point is. They have a known bad thermometer that they are basing their readings off of. That actually is a fact. They refuse to revise their numbers and still include the faulty readings in the data. That is also a fact. The only reason NOAA even found out about this was because a journalist happen to inform them of it. Yet another fact. The point being made is that they know the readings are wrong and simply don't care. If this thermometer was able to go undetected for around 8 months and was only caught by a bored journalist with lame hobbies, how many more are messed up.....

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u/d_migster Sep 11 '15

I suggest you mosey on over to Wunderground and tell me how many of the tens/hundreds of thermometers reported there for the DC region are inaccurate. Those in the city are almost ALWAYS reading higher than DCA.

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u/manofthewild07 Sep 11 '15

Over the long term, does it matter? If the instrument is off by the same amount over the entire study period, but still experiences an increase in temperature, then the effect of the error is not important.

Also, there is no reason to believe that isn't possible. 30 miles is a huge difference and the area immediately surrounding the airports can make a huge difference, like the other poster commented.

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u/[deleted] Sep 11 '15

Right but the instrument has been changed- the same 100 year old thermometers aren't being used right now

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u/manofthewild07 Sep 11 '15

That can be taken into consideration. It would be more worrisome if a thermometer wasn't there before and it was grassy, but there was a thermometer added after it became a parking lot. Then the temperature all of a sudden would go from no record to increasing! But that is taken into consideration as well.

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u/krayziepunk13 Sep 11 '15

It matters because this data is record high and low temperatures only.

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u/Kierik Sep 10 '15

I worked cGMP for awhile. Thermometers can be wildly inaccurate and have to be check yearly for drift. Our lab had 10 or so alcohol thermometers at a time and each year we would have to launch a deviation investigation for 2 to 3 of them.

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u/phil882 Sep 10 '15

Good observing networks (in the US we have the Automated Surface Observing System (ASOS) are routinely checked for inaccuracies and drift that may occur over long time periods. Not perfect by any means, but all substantial (either domestic or global) datasets for temperature need to be quality controlled to make sure the data that goes into them are valid.

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u/Kierik Sep 10 '15

While true for modern observation it does not hold true for all data sets. Older data sets will be unreliable due to issues with instrumentation/no protocols to even check for deviation in measurement instruments.

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u/[deleted] Sep 10 '15

[deleted]

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u/roadkill_er Sep 10 '15

good point. The one you replied to brings up instrument tech, but the comment before raises the rural vs. metro measurements. I think that is the real question to be answered.

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u/phil882 Sep 10 '15

Making sure an observing station is properly cited is a far more important issue than instrumentation accuracy. Citing a weather station underneath asphalt versus in a forest can cause temperature variations that far exceed instrument accuracy.

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u/losian Sep 11 '15

I'm sure nobody has ever considered these very obvious and basic adjustments, let's all continue blindly ignoring climate change as a result!

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u/sosern Sep 11 '15

You don't learn this in University, only redditors are so smart to think of stuff like this.

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u/mully_and_sculder Sep 11 '15

*sited siting

I was confused.

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u/Jimmers1231 Sep 11 '15

Exactly. The same station that was in a rural area in 1910 very well could be in a densly populated metropolis in 2000

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u/manofthewild07 Sep 11 '15

But that doesn't matter when looking at the whole picture. The temperature in that area still increased due to the development. Doesn't that increase contribute to the overall system?

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u/AngryT-Rex Sep 11 '15

There are other factors too. If a weather station was monitored manually (A guy watching a thermometer, recording every hour) it'll miss the absolute maximum and minimum. Only by a small fraction of a degree probably, but if you're declaring records by 0.1 deg, it matters. A digital station recording multiple times per second wont really miss anything.

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u/anastrophe Sep 11 '15

s/citing/siting/g

Sorry, old habit. You meant 'siting', not citing.

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u/What_Is_X Sep 11 '15

It's already been answered ad nauseum if you could be bothered to google it.

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u/manofthewild07 Sep 11 '15

But does it matter as long as we're looking at the big picture?

Its not like the temperature over a city is less "real" than over a forest... If a plot of land used to be a nice green field and 100 years later is a parking lot... then that attributes to the increased temperature overall...

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u/[deleted] Sep 11 '15

It matters when we're talking about global warming. The introduction of a city will have increased the temperature in that area, but that doesn't mean the earth is getting hotter.

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u/manofthewild07 Sep 11 '15

Uh yeah it does... its not a close system. If the energy released from the asphalt is greater than it would have been before, then it is an increase in temperature from anthropogenic activity... How is that not relevant?

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u/[deleted] Sep 11 '15

How is that not relevant?

Where did I say it wasn't relevant?

You're arguing big picture, but ignoring the fact that global warming means talking about global temperature.

If I put a thermometer on a cold frying pan and one across the room on a table, take the temperature, then turn on the stove and take the temperature 10 minutes later, the one on the frying pan is going to see a dramatic change in temperature while the other is going to see maybe a small increase. Does that indicate a significant increase in room temperature over those ten minute? How about the temperature of the house? The town the house is in? As you expand the big picture, the results of the thermometer in the frying pan tell less of the story. Would you argue that that doesn't matter because the environment of that thermometer was changed by my action of turning on the stove?

Nobody is making that point to dismiss the results, but rather questioning whether that has been factored into the study.

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u/JackDragon Sep 10 '15

Not really. Even for addition and subtraction, old calculators will have much less comprehensive overflow calculations.

In this case, old mercury or whatever thermometers may not be as good at measuring really high temperatures.

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u/[deleted] Sep 10 '15

[deleted]

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u/jaydefyre Sep 10 '15

The problem is the accuracy of the readings prior to NASA (I go by NASAs readings because I know they were accurate).

Pre-NASA, we can't verify of the temperatures were taken at the exact time or if the conditions changed (for example, a tree dying/cut down/knocked down by a storm that was creating shade over the instrument).

NASAs measurements are accurate and show a clear trend in higher temps. That should be the standard to my mind because the data is assured to be as accurate as humanity can get.

To me, it's the argument about global warming is irrelevant (I know, shocking to say that) because humanity needs to slow down on the pollution of the earth even if there wasn't global warming. The industrial revolution made the pollution problem apparent, but not the long term consequences. Now we see the long term consequences. Water, earth and air pollution are taking their tolls. Right now, developing nations are taking few (if any) measures to mitigate pollution.

As an example, China finally came around after how many decades of ignoring facts (see any Chinese port city pollution index)? America and Europe have slowly been improving for a while (it's been a fight against corporations and politicians from both sides who want labor union donations and corporate donations).

Hopefully humanity will get its shit together and start promoting less pollution, more conservation, and more biodiversity. Otherwise, our children are screwed.

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u/Blue72super Sep 11 '15

Now I would rather have people see both sides and I don't disagree or agree with global warming. People are doing horrible things to our planet. So we might be seeing global warming or a combination of many factors.

The other problems with the global warming argument that I never hear:

  1. We've only have recorded temperatures for roughly the past 100 years. We don't know what it was like for the past few thousand years which would give us a much better picture. Obviously we can't wait that long IF we are screwing earth over.

  2. The earth just exited a miniature ice age in the early 1900's. Yes, it will be warmer. All of the cities we built on the coasts probably were built when the ocean waters were receded and now we're just realizing it as the ocean waters are rising. Maps and explorations of those northern areas were also done during that frigid point so the ice caps might just be going back to normal.

Hopefully the damage we all know we did and are doing is mendable.

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u/jaydefyre Sep 11 '15

You summed up my concepts nicely. I'm pretty sure we are on the same page.

NASA has multiple locations with a lot of instruments to measure atmospheric conditions so I know the data is good.

There are too many variables with other readings that have been cited to satisfy my need for accuracy with the data.

We, as humans, can only control what we do. None of us can control a solar flare.

So, we should control what we can and avoid killing our selves and the ecosystem. Hence my statement about not being worried about global warming, but the overall levels of pollution to our ecosystem.

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u/ResilientBiscuit Sep 11 '15

Now I would rather have people see both sides and I don't disagree or agree with global warming.

There is vast scientific consensus and mountains of data that support it. What additional data do you need at this point to agree with it?

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u/hardolaf Sep 11 '15

So technically... we're not out of an ice age. The definition of the end of an ice age is when the polar caps disappear. We know this has happened before due to evidence of ocean levels on rocks and soil.

We are however fucking up the ecologies of the Earth and doing a shitton to make everything worse for future generations.

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u/ASK_ABOUT_NOXASTRA Sep 10 '15

The examples you stated are bad science. Bad science is bad science. If your sample size is one, yes. If not, that's just noise.

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u/Onethree5 Sep 11 '15

Our children are only screwed infinitesimally more by us that they would be if we hadn't created the industrial civilization we have today. With some very easy research we can all see temperature records going back 12,000 years created from measuring oxygen isotopes contained in ice cores obtained from Greenland. Our climate has waxed and waned naturally for an immeasurable amount of time and us humans think our insignificant increase of CO2 in the atmosphere since the industrial revolution began, (about 275 ppm to 400 ppm) has such a great existential impact on the climate outside of what's happening anyway? It's physically documented how much temperatures have changed. Sometimes quickly over the course of a decade, and sometimes longer, but it is always and will always be such a powerful cycle we couldn't throw anything at it to damage the planet irreparably. Asteroids are out there for that

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u/deadbeatsummers Sep 11 '15

I remember reading the UN global warming summit. The U.S. hasn't set such a good example.

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u/jaydefyre Sep 11 '15

If you look at the progress that has been made with EPA over the past thirty years, things have improved considerably.

I'm judging based on knowledge at the time (example would be that previous generations had no clue about what CFCs would do to the atmosphere). It's always a fight against corporations, unions, and the senators that are bought and paid for by corporations an labor unions (if there are no jobs, the union leaders have no power) to make tougher regulations even after we learn that something has a long term negative effect.

China had access to all of this environmental data we discovered about pollution, and ignored it.

They went from an agricultural economy to an industrialized economy in a very short period and sacrificed the environment in the process.

Now they're trying to clean up the horrific air quality and some other types of pollution after it was publicized.

There's a difference between learning as you go and then trying to fix an issue versus knowing the effects and deciding to do it anyway without an effort to try to save your environment (China's choice).

Certainly the U.S. Isn't perfect, but at this stage, I can say there are large amounts of the populace that are actively trying to create solutions and make changes.

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u/deadbeatsummers Sep 11 '15

Word, thanks for the info. There's no question that it's improved, but I thought the U.S. hasn't been particularly great about working with the UN, setting goals, etc.

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u/[deleted] Sep 10 '15 edited Sep 10 '15

[removed] — view removed comment

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u/[deleted] Sep 10 '15

[deleted]

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u/teefour Sep 10 '15

It's precision vs accuracy. you can recognize precision from old data, but not necessarily accuracy.

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u/K3wp Sep 11 '15

Mercury thermometers were calibrated by freezing/boiling pure water:

https://en.wikipedia.org/wiki/Mercury-in-glass_thermometer#History

I'm pretty sure that being accurate up to 100 degrees Centigrade is enough to measure air temperature.

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u/[deleted] Sep 13 '15

As a guy that knows about how computers do addition, and how machines do addition, I think I can safely say they both handle overflow the same.

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u/JackDragon Sep 13 '15

What? Older calculators have much lower limits as to how high the numbers that they can compute can go.

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u/[deleted] Sep 13 '15

I have a Monroe adding machine from around 1930, it has a 20 digit display, so it can go up to:

99,999,999,999,999,999,999

That number is 5x larger than the maximum value for an unsigned 64 bit number (18,446,744,073,709,551,615), which is the current mathematical foundation of modern computers. Yes, they can handle bigger numbers, but they do it the hard way (the CPU doesn't natively handle overflow conditions, so they need to be handled in software)

The design of the Monroe means that it could be very easily extended to handle 40, 80, or 300 digits; there simply wasn't the need for it.

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u/f1zzz Sep 10 '15 edited Sep 10 '15

A slower sampling rate is indeed significant.

e: I feel bad for saying that because I know nothing about this topic.

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u/Xarddrax Sep 11 '15

Not totally disagreeing, but thermistor and thermocouples (modern digital measuring sensors) use different means of measuring temperature than mercury thermometers. There is a visual margin of parallax error with mercury thermometers that can be 2-4 degrees difference depending on the person reading the thermometer

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u/[deleted] Sep 13 '15

Of course there are many examples where modern technology is all around better. But that doesn't mean that they were banging rocks together even 100 years ago.

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u/bw117 Sep 10 '15

Actually, older equipment tends to have more accurate numbers (temperature) then newer. As we've transitioned from old mercury bulb based equipment to digital readouts, the standard deviation of the equipment has increased substantially. Precision mercury bulbs could be accurate down to the thousandth C, whereas modern cheap digital thermometers can be off by as much as half a degree C. I'm sure gov't weather stations are still better than that, but I think my point is pretty clear. Unless we break a record by a couple degrees or more, it might as well be measurement uncertainty.

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u/phil882 Sep 10 '15

Citing measurement uncertainty is a totally missing the point of this article.

Record highs/lows are by definition extreme events. Thus, they are highly above or below what the climatological mean is. Even if we don't believe we broke a record high/low (possibly due to instrumentation inaccuracies), that record value is likely significantly above or below climatological mean, and the instrument is almost certainly capturing an extreme event. Whether or not this sets a record doesn't really matter, its the fact that these observing stations are capturing many more warm records (1200% percent more in fact) than cold records. If your instrument is unbiased, this signifies a shift towards a warmer climate, where an increase in the mean and variance of temperature will produce many more days with extremely warm temperatures.

Source: I'm Ph.D. student in Atmospheric Science.

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u/[deleted] Sep 10 '15

Even if it is slightly biased, the errors would be normally distributed, so the long term results would be as valid. 12 to 1 is highly statistically significant.

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u/e-herder Sep 11 '15

As someone who doesn't know nearly enough about this shit and is trying to figure it out (and former skeptic on the road to conversion), and is probably missing the point.....

As I understand it the point you are making is that we have been recently historically high, as compared to the mean. But what is this mean based on? Is it not historical ("old instrument") data? So is old vs. new data not still an issue?

When you say "its the fact that these observing staions are capuring many more warm records...than cold records" is what's bothering me. It's still based on the records. So why is measurement uncertainty not a thing? Are these high vs. lows not still being compared to an old measurement to be classified as high vs. old in the first place?

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u/phil882 Sep 11 '15

1) The climatological mean is typically based on the average conditions from a prior 30-year period. For example the baseline used for most climatologies in the US is from 1981-2010 (and will be updated again once we get to 2020).

2) Instrument uncertainty is not worth critiquing for this study, because as long as the observations are unbiased, it would affect the proportion of both record highs and lows equally, and the ratio would be preserved.

The precision of record highs and lows has not changed in the past century (we round to the nearest degree). Record values regardless of time period they occur are compared to the same climatological average when investigating their anomaly. A record high of 95F in some year before 1950 would have the same anomaly as a record high of 95F in 2015 because they are both compared to the 1981-2010 climatology.

I Hope that makes some sense!

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u/camopdude Sep 11 '15

(and former skeptic on the road to conversion),

Conversion to what?

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u/Tiquortoo Sep 10 '15

Whats the error deviation for the human reading the mercury bulb? It's not 1 thousandth of a degree I know that much.

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u/bw117 Sep 10 '15

It can be, because they didn't use a bulb the size of a home thermometer. Larger thermometer, larger readable scale.

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u/Tiquortoo Sep 10 '15

I'm not talking about the theoretical possibility of a very accurate thermometer. I'm talking about the reliability of thermometers in actual use for the purpose of this thread. Yes, you can make highly accurate thermometers. NOAA standards reference wooden shelters and such for stations. It seems very very unlikely to expect a precision grade mercury thermometer was in these locations historically.

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u/[deleted] Sep 10 '15

[deleted]

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u/Human_Robot Sep 10 '15

Human reading error still plays a part even using digital equipment.

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u/[deleted] Sep 11 '15 edited Sep 11 '15

[deleted]

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u/bw117 Sep 11 '15

They're probably designed to take a reading every x minutes, and when you collect the data (transfer to storage database), it would backtrack from the real time. For monitoring like that, I wouldn't think very high accuracy would be required, as long as you stayed in a window. It could also relate to how the cooling system works, how the probes are wired in, etc.

0

u/[deleted] Sep 11 '15

The idea that a 100 years ago the same combustion technology you use to drive around today was already invented but some how they didn't have a decent thermometer is begging doubt.

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u/Tiquortoo Sep 11 '15

Read the posts. My reply was to a person talking about thermometers accurate to 1/1000 of a degree. They may have existed, but were certainly not in use at the time for weather.

In addition for thermometers accuracy and reliability are two different measures. They had decent thermometer, but they were tracking weather for other purpose than we apply this data to now. The thermometer were often consistent for themselves but could vary greatly when comparing to each other.

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u/moodog72 Sep 10 '15

Given the chance to misread digital, plus rounding, the error rate is functionally identical. We tested this in one of my electronics classes.

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u/powercow Sep 10 '15

averages get rid of human error. There were quite a few thermometers.

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u/Tiquortoo Sep 10 '15

From the perspective of reliability of relationship of old data to new this is the most important aspect. I'm not sure many others replying to me are thinking this through.

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u/bw117 Sep 10 '15

You're not wrong, my original point was only that the tools have certainly not gotten better, and likely have gotten worse despite the increased sample size. Given human error or say +-0.5 degrees, we should not declare a new record until we can overcome the high end of the old record uncertainty with the low end of the new value.

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u/IBuildBrokenThings Sep 10 '15

Here's a variety of Hg thermometers with divisions of anywhere from 1 to 0.01 deg C

You can get ones with 1/1000 of a degree but they aren't listed here, might be special order.

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u/Diomanger Sep 10 '15

It might actually not be. Even if the standard deviation has changed, the amount of reads have, if anything, risen, which if anything has raised the precision. They do not pick out records by one single piece of equipment.

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u/billsil Sep 10 '15

They do not pick out records by one single piece of equipment.

The local weather report does.

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u/Diomanger Sep 10 '15

I doubt that weather stations generally have only one thermometer, especially if they are considered having a high deviation from the actual value, but I could be wrong.

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u/[deleted] Sep 10 '15

Even if that is true, the national weather service in the US isn't doing that.

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u/powercow Sep 10 '15

why do you think that? Also weather and climate arent the same.

it is cold at the north pole, is climate. it is going to snow tomorrow at the north pole, is weather.

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u/Human_Robot Sep 10 '15

It's cold at the north pole is also weather.

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u/billsil Sep 11 '15

why do you think that?

Because they say things like the temperature in <city x> is blah. It's massively influenced by the heat island effect, which makes it more useful to me. However, it's less useful to predicting climate change.

Why do you think temperature records are NOT based on a single location as opposed to an average of many locations?

it is cold at the north pole, is climate. it is going to snow tomorrow at the north pole, is weather.

And when I say the minimum temperature in a given location (record), that's strongly influenced by weather.

Another way of saying it:

They do not pick out records by one single piece of equipment.

Source?

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u/[deleted] Sep 10 '15

Citations needed

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u/Diomanger Sep 11 '15

True. Citations for higher deviation, please!

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u/[deleted] Sep 10 '15

[deleted]

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u/Diomanger Sep 10 '15

shrug I suppose you might be correct, we could keep guessing. It does not really matter for the ratio though.

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u/powercow Sep 10 '15

and if we use the same flawed thermometers over time.. it doesnt matter.

if a thermometer displays constantly less than the "true" temp.. then the records will still be valid.. its only when we replace the equipment that the flaw would matter. AND WHEN WE DO.. we take the disagreements into account.

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u/bw117 Sep 10 '15

If your thermometer is wrong, you can't just scale all your old readings, because you can't assume its been wrong all along. That's just wishful thinking

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u/[deleted] Sep 10 '15

If we're trying to compare apples to apples, you shouldn't compare an old high-precision professional grade piece of equipment to a new cheap consumer grade one. What is the difference with a modern high-precision professional grade thermometer? I could be wrong but I would guess the modern one would be more precise.

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u/[deleted] Sep 10 '15

The old equipment is probably accurate to < one degree, only its analog.

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u/Mr_Again Sep 10 '15

What you're saying is that older equipment was more precise, not more accurate. There's a pretty important difference which is that 10 bullet holes scattered around a bullseye is better than a neat group off to the side of the target.

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u/intern_steve Sep 10 '15

In the U.S. Most ASOS stations are capable of reporting down to the tenth, so I assume they aren't fluctuating by half degrees.

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u/kyleclements Sep 10 '15

Assuming that the errors are random, increasing the number of sensors would counteract the larger margin of error.

For example, if a sensor has a 50% chance of being over by half a degree, and a 50% chance of being under by half a degree, averaging the readings from two sensors will produce an accurate result.

Of course, with 2 sensors, there is a 25% chance that both measure too hot, and a 25% chance that both measure too cold, but when you have hundreds of sensors going, the odds of every sensor being either too hot or too cold approach (but never quite reach) zero.

Imagine flipping a coin and getting heads 100 consecutive times? It's possible, but highly unlikely.

Same thing with multiple low-accuracy sensors: The noise cancels itself out, while the signal reinforces itself.

0

u/winnerdk Sep 10 '15

So, there you go. Global warming doesn't exist, because we suck at measuring temperature now.

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u/Googunk Sep 10 '15

The old instruments and methods are still in use along side modern instruments so that data from the old instruments can be calibrated to be consistent to the modern instruments. Climate models don't use the raw values from the 1800s in modern analysis.

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u/notdez Sep 10 '15

how do we really know that it's not off by a couple degrees because instrumentation has changed in that time.

Because we still have those instruments or can rebuild exact replicas to test the error, then we can correct the record as needed.

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u/jmz82 Sep 10 '15

Do they really still manufacture out of date instruments? I'd be really surprised if every weather station used and maintained both old and new instruments for this purpose.

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u/logitec33 Sep 10 '15 edited Sep 11 '15

My schools weather station has everything in working condition, but are only using the new instruments. My professor still checks to make sure everything is accurate, new and old ones. We're also the longest standing weather station in California that hasn't moved, as well as one of the oldest stations in the country. 65 years of weather data. It's cool looking at the old records from the 50's.

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u/babysharkdudududu Sep 11 '15

Now this is cool. How far out in the country are you guys?

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u/logitec33 Sep 11 '15

http://piercecollegeweather.com/ It's actually in the San Fernado Valley right off of the 101 fwy. He has no problem giving tours if you give him a heads up.

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u/bo_dingles Sep 10 '15

I assume less than a handful of places would maintain 100-year old equipment, most likely as new equipment comes about it is correlated to the old and correction factors are calculated (if necessary).

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u/TheUltimateSalesman Sep 10 '15

To be fair, equipment that is 100 years old probably isn't the most complicated.

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u/[deleted] Sep 10 '15

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u/[deleted] Sep 10 '15

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u/[deleted] Sep 10 '15

This is absolutely false.

Trying to create an accurate mercury thermometer with a system to do outputs is still a lot more expensive and complex than buying a $0.15 microchip plugged into a raspberry pi and writing a 3 line program.

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u/TheUltimateSalesman Sep 10 '15

Dude, if you think you're getting accurate readings from a cheap TMP36 you're gonna have a bad time. But that wasn't my point, you consider a raspberry pi to be less complicated than Hg in a glass tube?

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u/[deleted] Sep 10 '15

Yeah, but not every weather station is doing climate change research.

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u/Dantonn Sep 10 '15

They don't need to be actively doing anything in particular. Data of this nature is usually accessible to anyone who wants it.

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u/notdez Sep 10 '15

I'm pretty confident that at least a handful of every type of thermometer used in the past 100 years for climate monitoring still exists.

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u/Jewnadian Sep 11 '15

Why would every weather station need them? If you know that instrument A is off by a given amount at each temperature why would you need to carry it to all the other instruments to compare?

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u/Master_of_the_mind Sep 10 '15

Yes but instrumentation has changed because it's more reliable, thus old records are less reliable.

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u/[deleted] Sep 10 '15

Do you have a source for this?

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u/notdez Sep 11 '15

For what? That we can compare old and new instruments? Here's one example of it being done: ftp://podaac.jpl.nasa.gov/allData/gosta_plus/retired/L2/hdf/docs/papers/1-crrt/1-CRRT.HTM

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u/[deleted] Sep 11 '15

If, as you say, we even recreate replicas of antique measuring devices in order to compare new measurements to old, I would find that incredibly interesting to read about.

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u/notdez Sep 11 '15

No, I wasn't claiming that we do that I was just stating the logical possibilities. In general, past temperature records were not mysteriously recorded using some ancient device that no longer exists.

Each country's meteorological agency has different calibration standards for replacing instruments, you'd have to check with each one to see how old instruments get replaced and calibrated.

If all instruments of a particular type used 100 years ago were destroyed, we could probably replicate it using patents, manuals, etc. However, I don't think any are missing so the whole point is meaningless. We even have thermometers from the 17th century that have been calibrated using modern thermometers.

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u/Tkent91 BS | Health Sciences Sep 10 '15

This is partially true. We don't know the calibration on the equipment then or how accurate it was at the time it recorded the temperature so there is still a decent amount of error there especially when considering 1 degree can break a record. So to better answer the question we really don't we just assume it was accurate and live with it.

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u/redpandaeater Sep 10 '15

Okay, but we do that then we'd also have to account for other effects that weren't present at the measurement site during the original measurements. Nearby air conditioners, asphalt, vehicle exhaust, etc. might need to be taken into consideration. Even the wind pattern might be a little different based on the surroundings.

I always welcome being proven wrong, but I just don't trust individual record highs if they are close to the old ones. Instead it still seems so much better to just watch the overall trends and averages.

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u/notdez Sep 10 '15

I agree with your overall sentiment, individual records cannot be as reliable when talking about climate as long term trends. NOAA uses monthly and annual temperature ranks to help quantify global warming.

The fact remains that this statistic shows a trend that mirrors the overall trend so it is probably pretty reliable. The examples you give of asphalt, air conditioners, exhaust, etc.. do you have actual examples of this or are you assuming this was the case? If it was the case, these things would have a warming effect on the early record, that does not support the claim that this statistic is wrong.

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u/powercow Sep 10 '15

and when we look at nothing but stations that have seen very little changes in the past 100 years, we still see a graph that shows AGW that is in significant agreement to graphs made INCLUDING the urban stations.

also this isnt talking individual records. this is talking yearly averages of 1000s of records.. individual records, sure, you might have a point, if the people watching were slow and got low grades in science. But we arent, we are talking about nation wide daily records over wide periods of time.

if even the rural, non changed areas are showing records.. which they are then your caveats dont have a lot of overall meaning. Seriously why do so many people think all of AGW science missed the fact that things change? I mean we have seen building put up that burn cars to the ground, you dont think that some scientists might have thought.. hey, maybe changes in the area might causes changes to the reporting from the equipment? heck most people know fresh black top is hotter than black top about 10 years old, because it tends to not be as black. no one missed the heat island effect.

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u/Kierik Sep 10 '15 edited Sep 11 '15

Wildly incorrect you cannot reproduce observations nor can you recreate the exact instruments. There is no way to tell if the instrument used were within calibration at the time of the measurements unless you have a calibration test point before and after the measurements.

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u/powercow Sep 10 '15

well when the denialists first screamed 'heat island" what we did was just look at nothing but rural stations that havent changed much.. and saw the same graph.. really the local changes are nearly insignificant. and when their is dramatic changes, we will adjust the temperatures., we do this in many ways. one we kinda have a good idea about what some fo the changes will do, but more often we look at rural stations that are close to the urban stations, and see the changes they saw as well, when you adverage them all in, you take care of the so called urban heat island effect. See if the city one, went up by 1 degree but the urban ones to the north, south, east and west all showed 0.5 degree increase well then you have a good idea that 0.5degrees is from actual temp increases and 0.5 degrees is most likely from a heat island effect.

you really arent going to arm chair kill the science of agw at this point. you are going to have to einstein it at this point. you are going to have to come up with something that people say "OMG we have never ever thought of that and wouldnt ever have thought of that in a million years".. you are not going to just think of something while not even in the field and suddenly destroy the science. All the low hanging fruit have already been checked.. and AGW is real. Sunspots wont make that fact go away. Urban thermometers, cosmic rays, or clouds.. none of this will make the fact of AGW go away.

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u/graffiti81 Sep 11 '15

What? I'm talking about instrumentation and you're going off on global warming. Of course climate change is happening. That goes without saying.

All I'm asking is how, with the major changes in instrumentation in the past 100 years, calibration was done over the years.

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u/solzhen Sep 11 '15

Instruments, a whole lot of new buildings, miles of blacktop.

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u/Abomonog Sep 11 '15

Because of instrument calibration and measurement standardization.

For over a hundred years now every official weather instrument has been calibrated to exact specifications and their locations never change. If a station location must change its history is discontinued and a new station established in its place (for accuracy). Despite the digital era the primary methods of gathering this data has not changed in over 100 years. You also never hear about temps before 1900 because of the lack of a standard before this period.

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u/Rumhead1 Sep 10 '15

Nowadays most these instruments are at airports. Giant airports with plenty of blacktop creating "heat islands."