How real is global warming?

[Eli]

Originally posted by: FoBoT
fake

scam

false

big boogie man

greenie communist tree hugging hippies need a cause

BS

load of crap

smoke from @ss

Shrug.

Believe what you will, but like I said.. I think it's extremely naive to believe our presence here is having absolutely no effect. Infact, I would say that's virtually impossible.. Whether the effects will be catastrophic remains to be seen.

The fact is, our CO2 and other gas emissions have risen so dramatically in the last 50 years, it will probably take another 100 years for the effects to be seen. 50 years is nothing on Earth's time scale.

I do believe that we should watch it, though. We can't exactly leave the planet, and nobody is going to care about money or anything if the planet's degredation continues. IMO, it's common sense. It's like the snowball effect. Our emissions of CO2 and other gasses have grown exponentially, all the while our forest sizes have decreased exponentially. It's silly to blow it off as just another one of the Earth's cycles. Since this is our home, we should do what we can to preserve it.

To say this isn't going to have some effect on our planet, even if it is insignificant.. borders on stupidity.

We just don't know yet.

 

[silverpig]

Originally posted by: Eli

Originally posted by: DaZ
The earth has natural Warming and Cooling trends, where the average overal temperature of the Earth fluctuates between something like +4° and -4° Celcius. -4° would mean an Ice age.. Imagine, 20-30 feet of snow year round in Florida.. +4° Would mean melting of the polar ice caps and flooding of much of the planet.. Say good by to most of the Earths land.. not to mention any coastal city..

These changes happen over billions of years, and do not always go to the extremes..

Right now were on a natural upwards trend.. So very slowly over time, the overall average temperature will continue to rise, albeit, very slowly.. But the huge amouts of pollution we throw in the air, creating a 'blanket', is only helping to accelerate the rising average temperature.

I think the average temperature of the oceans have risen almost 1C in the last hundred years or so. Maybe it was 0.74C or something like that, don't really remember. Regardless, it is quite significant on a global scale.

Originally posted by: DaZ

Oh, I think the warming part is quite real. Most scientists are in agreement about that. The question that remains is why?

Im no real expert on this.. But couldnt it be something as simple as fluctuations in the Earths orbit? (As to what causes them, thats another question).

Again, im not sure on the numbers.. but imagine the temperature change if the Earth was a million miles closer to the sun, or a million miles away. Something like taht would make a HUGE difference here on the ground

I don't think the Earth's orbit changes. It would throw everything out of wack, it seems.....

The earth doesn't just sit in a perfectly circular orbit one distance from the sun... At/around January 4th the earth is at it's perihelion, or close point to the sun. It orbits at 147.5 million km from the sun. At/around July 4th the earth is at aphelion, 152.6 km from the sun.

So the earth's distance from the sun varies by 5.1 million km (3.2 million mi) every year.

 

[Eli]

Originally posted by: silverpig

The earth doesn't just sit in a perfectly circular orbit one distance from the sun... At/around January 4th the earth is at it's perihelion, or close point to the sun. It orbits at 147.5 million km from the sun. At/around July 4th the earth is at aphelion, 152.6 km from the sun.

So the earth's distance from the sun varies by 5.1 million km (3.2 million mi) every year.

Ahh, Interesting. I don't know much about astronomy, so it doesen't really surprise me.

Well, that just adds another variable to the whole thing. It is so complex, we don't even begin to understand..

 

[Vic]

Originally posted by: Eli
Shrug.

Believe what you will, but like I said.. I think it's extremely naive to believe our presence here is having absolutely no effect. Infact, I would say that's virtually impossible.. Whether the effects will be catastrophic remains to be seen.

The fact is, our CO2 and other gas emissions have risen so dramatically in the last 50 years, it will probably take another 100 years for the effects to be seen. 50 years is nothing on Earth's time scale.

I do believe that we should watch it, though. We can't exactly leave the planet, and nobody is going to care about money or anything if the planet's degredation continues. IMO, it's common sense. It's like the snowball effect. Our emissions of CO2 and other gasses have grown exponentially, all the while our forest sizes have decreased exponentially. It's silly to blow it off as just another one of the Earth's cycles. Since this is our home, we should do what we can to preserve it.

To say this isn't going to have some effect on our planet, even if it is insignificant.. borders on stupidity.

We just don't know yet.

You're right. We don't know. But what has proven itself to be quite clear is that we do more harm when we intervene with nature than if we had just let it fix the problem on its own. It's a very complex and self-balancing system and, like I said, temperature fluctuations similar to what we are experiencing now have occurred even in relatively recent human history.
One thing I have become quite certain of is that humans CANNOT destory the earth. Not even if we tried. Not even if every nuclear weapon on earth exploded simultaneously. The earth would survive and, after a time of healing (perhaps a LONG time), would once again give forth life. Just not human life...

 

[Eli]

Originally posted by: Vic

Originally posted by: Eli
Shrug.

Believe what you will, but like I said.. I think it's extremely naive to believe our presence here is having absolutely no effect. Infact, I would say that's virtually impossible.. Whether the effects will be catastrophic remains to be seen.

The fact is, our CO2 and other gas emissions have risen so dramatically in the last 50 years, it will probably take another 100 years for the effects to be seen. 50 years is nothing on Earth's time scale.

I do believe that we should watch it, though. We can't exactly leave the planet, and nobody is going to care about money or anything if the planet's degredation continues. IMO, it's common sense. It's like the snowball effect. Our emissions of CO2 and other gasses have grown exponentially, all the while our forest sizes have decreased exponentially. It's silly to blow it off as just another one of the Earth's cycles. Since this is our home, we should do what we can to preserve it.

To say this isn't going to have some effect on our planet, even if it is insignificant.. borders on stupidity.

We just don't know yet.

You're right. We don't know. But what has proven itself to be quite clear is that we do more harm when we intervene with nature than if we had just let it fix the problem on its own. It's a very complex and self-balancing system and, like I said, temperature fluctuations similar to what we are experiencing now have occurred even in relatively recent human history.
One thing I have become quite certain of is that humans CANNOT destory the earth. Not even if we tried. Not even if every nuclear weapon on earth exploded simultaneously. The earth would survive and, after a time of healing (perhaps a LONG time), would once again give forth life. Just not human life...

Yep, I agree. Everything we touch in nature, we destroy. I laugh everytime I hear the term "Forest Management" on the news.. It's like an oxymoron.. lol.

While we may not be able to really destroy the Earth, I still think it is wise to do our best to take care of it as long as we're living here. She could make life really miserable if it meant correcting a balance that we offset...

 

[JohnCU]

Yeah, it is kind of scary to think about how polluted stuff could be by the time we (18-19-20 year olds) get to 60 or 70...

 

[Eli]

Originally posted by: JohnCU
Yeah, it is kind of scary to think about how polluted stuff could be by the time we (18-19-20 year olds) get to 60 or 70...

Indeed. :Q

I like to think that our advances will become more environmentally friendly, though. That seems to be one of the major goals.. technology to do the same thing, only more efficiently.. which usually means more friendly for the environment.

I can't imagine what things will be like in the next 25 years, though. Things have changed so much in the last 25 years... I bet it will be nothing like we expect.

It's exciting.

 

[MovingTarget]

Well, most scientists are in agreement that we humans do have some role in the overall increase in temperature of our planet as of late. The debate lies in the true extent of our involvement. Some people I know say that environmental policy and restrictions should be rolled back some to benefit some businesses because they believe that it is part of a natural cycle. Even if it is really the case that the current warming trend is mainly attributed to a natural cycle, I do not believe that we should shrug off some more responsible and friendly environmental policy due to that. We should still continue to improve our environmental policies regardless, but that is just my opinion. However, I also believe more research needs to be done on this debate of man vs. nature in global warming impact...

 

[Squisher]

I believe the number I heard was that 75% of all scientists believe in global warming............











although only 17% of all climatologists do.

 

[WinkOsmosis]

Yeah, there is a cycle of warming and cooling. So does that mean when humans accelerate the warming it should be ignored?

 

[MovingTarget]

Sorry, I should have specified scientists that believe in global warming in my previous post. Not all scientists believe we are in a major warming trend, but there are quite a few that do. Although I tend to agree with this group, I still think man's impact on the environment, including the possibility of accellerating a global warming trend, should be researched more.

 

[KenGr]

Originally posted by: Eli[/b

Actually, we're still in an Ice Age as odd as that sounds.

I don't think we're technically still in it. If we are, we're at the very tail end of it. The ice has been melting for the last 10,000 - 20,000 years or so.

Like I said, we don't have accurate records for a large enough time frame to really know. We only have semi-accurate weather records for the last 100 years or so. We can "see" into the past due to geologic records, but the margin of error is too great and we don't know enough of the specifics to really come to any concrete conclusions.

I believe it is most correct to say that we appear to be at the end of a "mini Ice Age" as opposed to the last great Ice Age that peaked close to 20,000 years ago. Viewed in this context, the current "warming trend" appears to be a natural phenomena. After an warm weather period centered around 1000 AD, we began cooling around 1500 AD peaking in the early to mid 1800's, when it was terribly cold compared to today. The climate history is actually pretty accurate with respect to changes which could cause "catastropic" changes. Of course, these have never been truly catastophic (although it may have been pretty rough on the dinosaurs) in that the planet has readily adapted to swings much greater than postulated due to global warming.

The climate temperature history appears to be multiple superimposed curves. It is not possible to definitively state if the current temperatures are natural or not. The overall trend may be that we would always expect to get warmer and Ice Ages will never happen again. It's equally possible that Mexico will be covered with ski resorts in 1000 years.

 

[Syringer]

Hmm, so in a country like the US, or more specifically in a city like LA, how do conditions compare with that of say a city on the other side of the earth with no factories or cars?

 

[Eli]

Originally posted by: KenGr

Originally posted by: Eli

Actually, we're still in an Ice Age as odd as that sounds.

I don't think we're technically still in it. If we are, we're at the very tail end of it. The ice has been melting for the last 10,000 - 20,000 years or so.

Like I said, we don't have accurate records for a large enough time frame to really know. We only have semi-accurate weather records for the last 100 years or so. We can "see" into the past due to geologic records, but the margin of error is too great and we don't know enough of the specifics to really come to any concrete conclusions.

I believe it is most correct to say that we appear to be at the end of a "mini Ice Age" as opposed to the last great Ice Age that peaked close to 20,000 years ago. Viewed in this context, the current "warming trend" appears to be a natural phenomena. After an warm weather period centered around 1000 AD, we began cooling around 1500 AD peaking in the early to mid 1800's, when it was terribly cold compared to today. The climate history is actually pretty accurate with respect to changes which could cause "catastropic" changes. Of course, these have never been truly catastophic (although it may have been pretty rough on the dinosaurs) in that the planet has readily adapted to swings much greater than postulated due to global warming.

The climate temperature history appears to be multiple superimposed curves. It is not possible to definitively state if the current temperatures are natural or not. The overall trend may be that we would always expect to get warmer and Ice Ages will never happen again. It's equally possible that Mexico will be covered with ski resorts in 1000 years.

Ahh, interesting.

 

[leung324]

Originally posted by: Fudssa
It ain't real.

yes...think about the winter in east coast this year (jan to april)

 

[Eli]

Originally posted by: leung324

Originally posted by: Fudssa
It ain't real.

yes...think about the winter in east coast this year (jan to april)

Heh.

 

[B00ne]

Well nobody knows for sure how big human influence to global warming is, but it should be pretty clear, that our influence is significant.

Just look at the percentage of CO2 in our atmosphere the amount has increased tremendously in the last 100 years - unprecedented. Don't tell that has no effect, Also the continuing deforestation especially of the rain forest gotta be bad.

Fact is when we are buying products we seldom pay the real bill of that product, because environmental changes, the eating up of ntaural resources and the impact on the environment for obtaining them is al not payed for, earth is giving us a huge credit - do u think we can live of that credit forever? Or in other words even a system as big as earth does not have the ability to grant unlimited credit - so sooner or later we have to start to at least produce stuff without living off of that credit - that will be difficult enough, not even thinking of paying back.... (like repairing the damage done - seldom possible anyway)

 

[KthxBye]

Even if it is real, I don't really give a damn. I think we've all go bigger problems then what the temperature is going to be in a thousand years.

 

[KenGr]

Originally posted by: B00ne
Well nobody knows for sure how big human influence to global warming is, but it should be pretty clear, that our influence is significant.

Just look at the percentage of CO2 in our atmosphere the amount has increased tremendously in the last 100 years - unprecedented. Don't tell that has no effect, Also the continuing deforestation especially of the rain forest gotta be bad.

Fact is when we are buying products we seldom pay the real bill of that product, because environmental changes, the eating up of ntaural resources and the impact on the environment for obtaining them is al not payed for, earth is giving us a huge credit - do u think we can live of that credit forever? Or in other words even a system as big as earth does not have the ability to grant unlimited credit - so sooner or later we have to start to at least produce stuff without living off of that credit - that will be difficult enough, not even thinking of paying back.... (like repairing the damage done - seldom possible anyway)

Current CO2 have been found to be higher than in recent history, but the dramatic curve that is always shown to demonstrate this is actually quite misleading. At first glance it appears the CO2 level is three or four times higher now. It actually has a truncated axis and the increase is only about 30%. Still worth studying, but it always raises a flag if the data is being presented unfairly. Also, the "temperature increase" data also turns out to be a bit troubling. Although temperatures are increasing, the most reliable measurements seem to indicate the temperature increase has been leading, not lagging the CO2 increase.

Having spent some time doing computer modeling of complex thermodynamic systems, I'm very skeptical of the validity of the climate computer modeling. The number of assumptions required may allow the theory to be proven but will probably prevent much accuracy. I think we're a long way from any definitive answers.

While I'm not opposed to taking prudent steps to reduce CO2 emissions, I haven't seen any prudent steps proposed. Kyoto is a complete joke. Any plan that exempts China, India and the rest of the developing world, and refuses to give any credit for technologies like Nuclear power has to be politics, not science.

 

[FuzzyBee]

maybe we caused global warming on Mars, too.

 

[Eli]

Originally posted by: fuzzy bee
maybe we caused global warming on Mars, too.

Interesting.

 

[dullard]

Originally posted by: KenGr
Having spent some time doing computer modeling of complex thermodynamic systems, I'm very skeptical of the validity of the climate computer modeling. The number of assumptions required may allow the theory to be proven but will probably prevent much accuracy. I think we're a long way from any definitive answers.

Yep I've done similar calculations (thermal modeling is a major part my graduate research) and the possibility for errors is just enormous. One simple assumption about something that we don't have enough data on can dramatically alter the conclusions.

I just briefly scanned this thread, so sorry if these are repeats, but they are my thoughts on the subject:
1) It is a well known fact that cities alter the weather - in fact many storms are produced a few miles directly downwind of a city which is easilly seen on radars. One way cities alter the weather is by raising the LOCAL temperature. Cars burn fuel producing heat. Huses, industry, etc. all use energy producing heat. Where does this heat go? Into the air. The bigger the city the hotter it is than the surroundings (which is easilly seen on detailed temperature maps). The pavement on the streets and the dark shingles all absorb the suns energy and release it as heat - where outside the city plants absorb the energy and don't release as much as heat. Thus again the city is hotter than the surroundings. But this is only a LOCAL effect.
2) The temperatures used in global warming debates are officially taken at airports for the most part.
3) Airports are located in or next to the cities that are locally increasing in heat.
4) So the ground data shows clear warming as cities grow - but does this mean the rest of the world is warming? The answer is we have no data and thus no real way of knowing. The data shows the cities are getting hotter - but there is no ground temperature data even being taken in much of the wilderness areas.
5) What data do we have? NASA data from satellites shows that on average the non-city areas are not getting hotter. So I myself am not that conserned. Even if you pretend the NASA data isn't valid at the Earth surface (a common rebuttal to the NASA data), it is still valid in the upper atmosphere. This data clearly refutes the global warming simulations which show the upper atmosphere will be increasing in temperature as well.
6) Conclusion: Either the data or the simulations (or both) that show global warming exists is flawed. But that doesn't mean that global warming is false.
7) Instead most people studying this feel we need 10-15 more years of data to really know the answer (as well as 10-15 years of improved modeling and more powerful computers to more accurately model it). Only then will we have a better answer. Until then it is just assumptions.

Now lets for the sake of argument assume global warming is occuring. And of course we have SOME effect on our surroundings. Next the big question is why. Suppose you had a greenhouse. Suppose inside the greenhouse you measured the temperature and it was steady day after day and year after year. Now suppose you suddenly bring in tons of oil and light it on fire inside the greenhouse. And at the same time lets suppose you put a very thin coating on your greenhouse glass that probably makes it retain more heat - but the layer is not very powerful and not much is applied and it isn't applied very evenly with some large glass sections not getting any coating at all. Suddenly with this extra glass coating and roaring fire the thermometer next to the fire increases - day after day and year after year. Why did the thermometer go up? Is it (A) because a new fire was built inside the greenhouse or (B) because the greenhouse may be slightly more efficient. I'd have to say duh to that question: (A) is by far the major cause. (B) will likely have a very minor effect, but the temperature rise is almost intirely due to (A). Sadly I've never heard any global warming debates considering (A) they only focus on the much more minor effect of (B).

 

[Squisher]

Originally posted by: dullard

Originally posted by: KenGr
Having spent some time doing computer modeling of complex thermodynamic systems, I'm very skeptical of the validity of the climate computer modeling. The number of assumptions required may allow the theory to be proven but will probably prevent much accuracy. I think we're a long way from any definitive answers.

Yep I've done similar calculations (thermal modeling is a major part my graduate research) and the possibility for errors is just enormous. One simple assumption about something that we don't have enough data on can dramatically alter the conclusions.

I just briefly scanned this thread, so sorry if these are repeats, but they are my thoughts on the subject:
1) It is a well known fact that cities alter the weather - in fact many storms are produced a few miles directly downwind of a city which is easilly seen on radars. One way cities alter the weather is by raising the LOCAL temperature. Cars burn fuel producing heat. Huses, industry, etc. all use energy producing heat. Where does this heat go? Into the air. The bigger the city the hotter it is than the surroundings (which is easilly seen on detailed temperature maps). The pavement on the streets and the dark shingles all absorb the suns energy and release it as heat - where outside the city plants absorb the energy and don't release as much as heat. Thus again the city is hotter than the surroundings. But this is only a LOCAL effect.
2) The temperatures used in global warming debates are officially taken at airports for the most part.
3) Airports are located in or next to the cities that are locally increasing in heat.
4) So the ground data shows clear warming as cities grow - but does this mean the rest of the world is warming? The answer is we have no data and thus no real way of knowing. The data shows the cities are getting hotter - but there is no ground temperature data even being taken in much of the wilderness areas.
5) What data do we have? NASA data from satellites shows that on average the non-city areas are not getting hotter. So I myself am not that conserned. Even if you pretend the NASA data isn't valid at the Earth surface (a common rebuttal to the NASA data), it is still valid in the upper atmosphere. This data clearly refutes the global warming simulations which show the upper atmosphere will be increasing in temperature as well.
6) Conclusion: Either the data or the simulations (or both) that show global warming exists is flawed. But that doesn't mean that global warming is false.
7) Instead most people studying this feel we need 10-15 more years of data to really know the answer (as well as 10-15 years of improved modeling and more powerful computers to more accurately model it). Only then will we have a better answer. Until then it is just assumptions.

Now lets for the sake of argument assume global warming is occuring. And of course we have SOME effect on our surroundings. Next the big question is why. Suppose you had a greenhouse. Suppose inside the greenhouse you measured the temperature and it was steady day after day and year after year. Now suppose you suddenly bring in tons of oil and light it on fire inside the greenhouse. And at the same time lets suppose you put a very thin coating on your greenhouse glass that probably makes it retain more heat - but the layer is not very powerful and not much is applied and it isn't applied very evenly with some large glass sections not getting any coating at all. Suddenly with this extra glass coating and roaring fire the thermometer next to the fire increases - day after day and year after year. Why did the thermometer go up? Is it (A) because a new fire was built inside the greenhouse or (B) because the greenhouse may be slightly more efficient. I'd have to say duh to that question: (A) is by far the major cause. (B) will likely have a very minor effect, but the temperature rise is almost intirely due to (A). Sadly I've never heard any global warming debates considering (A) they only focus on the much more minor effect of (B).

dullard, that involvement of the temps being taken at airports is a new twist that I've never heard, but it seems very plausible. Urban sprawl here in Detroit has now caused Metro Airport to see many a subdivision spring up in its vicinity and the shear growth of metro communities to now include their local airports could be a major fly in the ointment to the sky is falling crowd. Hmmm.

 

[Eli]

Originally posted by: Squisher

Originally posted by: dullard

Originally posted by: KenGr
Having spent some time doing computer modeling of complex thermodynamic systems, I'm very skeptical of the validity of the climate computer modeling. The number of assumptions required may allow the theory to be proven but will probably prevent much accuracy. I think we're a long way from any definitive answers.

Yep I've done similar calculations (thermal modeling is a major part my graduate research) and the possibility for errors is just enormous. One simple assumption about something that we don't have enough data on can dramatically alter the conclusions.

I just briefly scanned this thread, so sorry if these are repeats, but they are my thoughts on the subject:
1) It is a well known fact that cities alter the weather - in fact many storms are produced a few miles directly downwind of a city which is easilly seen on radars. One way cities alter the weather is by raising the LOCAL temperature. Cars burn fuel producing heat. Huses, industry, etc. all use energy producing heat. Where does this heat go? Into the air. The bigger the city the hotter it is than the surroundings (which is easilly seen on detailed temperature maps). The pavement on the streets and the dark shingles all absorb the suns energy and release it as heat - where outside the city plants absorb the energy and don't release as much as heat. Thus again the city is hotter than the surroundings. But this is only a LOCAL effect.
2) The temperatures used in global warming debates are officially taken at airports for the most part.
3) Airports are located in or next to the cities that are locally increasing in heat.
4) So the ground data shows clear warming as cities grow - but does this mean the rest of the world is warming? The answer is we have no data and thus no real way of knowing. The data shows the cities are getting hotter - but there is no ground temperature data even being taken in much of the wilderness areas.
5) What data do we have? NASA data from satellites shows that on average the non-city areas are not getting hotter. So I myself am not that conserned. Even if you pretend the NASA data isn't valid at the Earth surface (a common rebuttal to the NASA data), it is still valid in the upper atmosphere. This data clearly refutes the global warming simulations which show the upper atmosphere will be increasing in temperature as well.
6) Conclusion: Either the data or the simulations (or both) that show global warming exists is flawed. But that doesn't mean that global warming is false.
7) Instead most people studying this feel we need 10-15 more years of data to really know the answer (as well as 10-15 years of improved modeling and more powerful computers to more accurately model it). Only then will we have a better answer. Until then it is just assumptions.

Now lets for the sake of argument assume global warming is occuring. And of course we have SOME effect on our surroundings. Next the big question is why. Suppose you had a greenhouse. Suppose inside the greenhouse you measured the temperature and it was steady day after day and year after year. Now suppose you suddenly bring in tons of oil and light it on fire inside the greenhouse. And at the same time lets suppose you put a very thin coating on your greenhouse glass that probably makes it retain more heat - but the layer is not very powerful and not much is applied and it isn't applied very evenly with some large glass sections not getting any coating at all. Suddenly with this extra glass coating and roaring fire the thermometer next to the fire increases - day after day and year after year. Why did the thermometer go up? Is it (A) because a new fire was built inside the greenhouse or (B) because the greenhouse may be slightly more efficient. I'd have to say duh to that question: (A) is by far the major cause. (B) will likely have a very minor effect, but the temperature rise is almost intirely due to (A). Sadly I've never heard any global warming debates considering (A) they only focus on the much more minor effect of (B).

dullard, that involvement of the temps being taken at airports is a new twist that I've never heard, but it seems very plausible. Urban sprawl here in Detroit has now caused Metro Airport to see many a subdivision spring up in its vicinity and the shear growth of metro communities to now include their local airports could be a major fly in the ointment to the sky is falling crowd. Hmmm.

Who started that practice, anyway?

I've always thought it was stupid that the official temperature was taken here at the Portland Airport. Here, the airport is located right on the Columbia River, so it is almost always several degrees cooler than in town.

 

[dullard]

Originally posted by: Squisher
dullard, that involvement of the temps being taken at airports is a new twist that I've never heard, but it seems very plausible. Urban sprawl here in Detroit has now caused Metro Airport to see many a subdivision spring up in its vicinity and the shear growth of metro communities to now include their local airports could be a major fly in the ointment to the sky is falling crowd. Hmmm.

That is probably the major argument made from both the global warming skeptics and the people like me sitting on the fence waiting for enough data to be taken. The earth is mostly covered by water. So how many places over the ocean are the temperatures of the air being taken regularly? Next to none. How many places over the poles are the temperatures being taken regularly (very few, but it is done in a limited place). What about in the remote regions of the country. Heck what about the remote 3rd world countries? All of those places we have almost no data at all. The vast, vast majority of our data is taken in cities which of course we all know heat up as the city grows. So is the heat up taking place everywhere or just the cities? Without that data how do you know?

Eli
Who started that practice, anyway?

I've always thought it was stupid that the official temperature was taken here at the Portland Airport. Here, the airport is located right on the Columbia River, so it is almost always several degrees cooler than in town

I think it is from convenience. Airports already need accurate weather data to protect the planes/passengers from bad weather. So it just became the standard place to take the data. Also how do you take the data repeatedly at the north pole? How do you take it in the middle of the Atlantic ocean? It just isn't practical.