Watts Posts Paper Claiming "Spurious" Warming in U.S. Climate Record

[LakeEffectKing]

it seems like he was unhappy with the conclusions of Fall et al. 2011 (http://www.agu.org/p...0JD015146.shtml) and is trying to gerrymander a result that would be in line with his surfacestations.org stuff.

Conjecture, but point noted.

[Ottawa Blizzard]

Would this explain temp differences in say Gore Bay, Moosonee or Blair? Too many places that haven't grown show the same pattern. If I drive out of Cambridge in winter temps depend on the direction I'm headed, leaving Kitchener things usually get warmer & I think the same it true of London unless you head north.

IThe urban heat island effect was pretty well covered by BEST.

Terry

Point taken, but I can tell you that if in the Fall or winter you drive south down the 416 out of Ottawa, the temperature can drop by as much as 6 degrees celcius on a calm, clear night. Last october, when driving back to Toronto around 10pm, the temperature fell from 10 celcius to 3 celcius on the 416.

[Vergent]

The paper can be found at:

http://wattsupwithth..._webrelease.pdf

Some quick thoughts:

- The paper makes the claim that the lower tropospheric temperatures (which have been running cooler than surface temperatures) are an upper bound. Claims they trend faster than surface temperatures. Recent literature suggests otherwise. Instead, the lower troposphere has been warming more slowly than the surface.

- The Berkeley Earth Surfact Temperature (BEST) study reviewed more than 39,000 stations, both in the U.S. and globally. The Watts study is based on 779 U.S. stations.

The lower tropospheric temperatures are 7/10 sst influenced. We know, especially with the double nina, that these temperatures have warmed less than the land. Let me pick 779 (just enough for statistical significance) out of 39,000 and you can make it say watterver you you want. Consider the source, he is just playing annother shell game to give the trolls ammo to disrupt any thread. I'm glad you gave it it's own thread.

[LakeEffectKing]

he was a co-author on the Fall paper.

Fact....also noted.

[Entropy]

The lower tropospheric temperatures are 7/10 sst influenced. We know, especially with the double nina, that these temperatures have warmed less than the land. Let me pick 779 (just enough for statistical significance) out of 39,000 and you can make it say watterver you you want. Consider the source, he is just playing annother shell game to give the trolls ammo to disrupt any thread. I'm glad you gave it it's own thread.

The UAH database lists the linear trend for the continental United States at +0.23C/decade since 1979. See: http://vortex.nsstc....t2lt/uahncdc.lt. This is lower than the trend for USHCN reported by NCDC, but also significantly higher than the trend reported in the Watts study.

Just for the heck of it, I did my own analysis of the UAH data using the data to create a chart in Excel. I came up with a trend of +0.0019C/month, which comes out to +0.228C/decade, or +0.23C/decade when rounded to two significant figures. I've attached the chart below, which shows an unmistakable warming trend for the continental U.S. Also, I'm not sure whether the NCDC figure includes Alaska & Hawaii, in addition to the contiguous 48 states. My understanding is that Alaska has generally been warming more rapidly than the Lower 48. So if it includes those two states, that could account for some of the discrepancy. Although Alaska is only one state, it is the largest in area.

[Jonger]

Point taken, but I can tell you that if in the Fall or winter you drive south down the 416 out of Ottawa, the temperature can drop by as much as 6 degrees celcius on a calm, clear night. Last october, when driving back to Toronto around 10pm, the temperature fell from 10 celcius to 3 celcius on the 416.

This Friday I'm going to be in downtown Detroit, I'm going to make a timestamped pictorial log of the night time temps over a 50 mile drive. My intial guess is around 10 degrees difference over the stretch.

[TerryM]

This Friday I'm going to be in downtown Detroit, I'm going to make a timestamped pictorial log of the night time temps over a 50 mile drive. My intial guess is around 10 degrees difference over the stretch.

But is there anyone still living in downtown Detroit? Saw a documentary last week that painted a terribly bleak picture. From freeways without cars to buildings without roofs, it might make an interesting study, but I don't know of any comparable city.

Not trying to be snarky I'll be interested in what you find. I know when smog levels in So Cal abated weather was noticeably warmer during the day - some times you could actually see the sun!

I've wondered if in cities that have lost their smokestack industries, there might not be an up tick in daytime temperatures, probably offset by cooler nights.

Hamilton's steel mills recently shut down. I'll see if I can find any correlation between this event and temperature extremes.

Terry

[Jonger]

But is there anyone still living in downtown Detroit? Saw a documentary last week that painted a terribly bleak picture. From freeways without cars to buildings without roofs, it might make an interesting study, but I don't know of any comparable city.

Not trying to be snarky I'll be interested in what you find. I know when smog levels in So Cal abated weather was noticeably warmer during the day - some times you could actually see the sun!

I've wondered if in cities that have lost their smokestack industries, there might not be an up tick in daytime temperatures, probably offset by cooler nights.

Hamilton's steel mills recently shut down. I'll see if I can find any correlation between this event and temperature extremes.

Terry

The buildings are still there, I highly doubt the physical bodies of the people are contributing to the warming. Obviously this won't be a peer reviewed study, just something for fun.

Detroit has quite low air pollution compared to "valley" cities, I would think Windsor would be the recipient of most of the little pollution there is.

[TerryM]

The buildings are still there, I highly doubt the physical bodies of the people are contributing to the warming. Obviously this won't be a peer reviewed study, just something for fun.

Detroit has quite low air pollution compared to "valley" cities, I would think Windsor would be the recipient of most of the little pollution there is.

Yeah - I doubt there are too many active smokestacks left. Windsor is beautiful at present, but I wasn't around when auto production was at it's peak.

I'll be interested in what you find, and I'l try a similar test up this way. There are 4 metro areas that I frequent, so I'll just note the temps and times when I'm headed into or out of them.

Terry

[Msalgado]

So I read through the paper a couple of times but what I'm missing is the "why". I get that Watts thinks the methods used by NOAA are flawed, but does he ever specifically state why his are correct and more appropriate to use than the others?

[Snow_Miser]

So I read through the paper a couple of times but what I'm missing is the "why". I get that Watts thinks the methods used by NOAA are flawed, but does he ever specifically state why his are correct and more appropriate to use than the others?

From what I read on the press release, the new Watts et. al 2012 study used a newer classifying method from Leroy 2010. Muller et. al used a classifying method from an older paper, Leroy 1999. Why Muller et. al chose to ignore the newer classifying method is beyond me.

The new Leroy 2010 classifying method is different than Leroy 1999 in the sense that Leroy 2010 takes area of the heat sinks into account when quantifying the heat sinks. This is what gave Watts et. al the conclusion that they got that half of the warming over the late-20th century was due to artificial urban and adjustment warming biases.

This is similar to another study earlier that also found that nearly half of the warming was due to urbanization biases over the last 100 years, except this study deals with the last 30 years.

[Snow_Miser]

Dr. Roger Pielke Sr. Is strongly praising the new Watts et. al paper FWIW

http://pielkeclimatesci.wordpress.com/2012/07/29/comments-on-the-game-changer-new-paper-an-area-and-distance-weighted-analysis-of-the-impacts-of-station-exposure-on-the-u-s-historical-climatology-network-temperatures-and-temperature-trends-by-w/

[Msalgado]

From what I read on the press release, the new Watts et. al 2012 study used a newer classifying method from Leroy 2010. Muller et. al used a classifying method from an older paper, Leroy 1999. Why Muller et. al chose to ignore the newer classifying method is beyond me.

The new Leroy 2010 classifying method is different than Leroy 1999 in the sense that Leroy 2010 takes area of the heat sinks into account when quantifying the heat sinks. This is what gave Watts et. al the conclusion that they got that half of the warming over the late-20th century was due to artificial urban and adjustment warming biases.

This is similar to another study earlier that also found that nearly half of the warming was due to urbanization biases over the last 100 years, except this study deals with the last 30 years.

See I fail to see how a new classification system alone brings up such huge changes. If you already came to the conclusion that the different groups of stations are telling you the same basic thing, then reshuffling the stations shouldn't have a large affect.

[The_Global_Warmer]

So what's the verdict?

[PhillipS]

So what's the verdict?

I think it is still too early to reach a verdict on Watts' draft paper - but there are increasing signs that it is deeply flawed.

One point I've seen in several articles is that he basic premise of the paper - that the weather stations can be classified by today's siting conditions and that classification can be used to assess the stations' warming trends over thirty or so years - isn't valid because a recent survey of a weather station's site tells nothing about the site conditions decades ago. A site that is great now may have been poor years ago and a site that's poor now may have been great when the site was initially established. The analogy I liked was if you took a survey of a neighborhood today and assessed the condition of the houses there - what would that tell you about the condition of those same houses in 1979? Would it be scientifically accurate to assume that houses in great shape today were in great shape over the whole period of time, and that houses currently run-down have always been run-down - in fact were built in a run-down condition? Without a continuous record of the neighborhood there isn't much that can be safely assumed. But the Watts' paper ignores this issue and classifies weather stations based on site surveys since 2008.

But there are more serious flaws in the paper. Watts hasn't released the full methodology and data for tthe paper but it appears that the authors forgot to factor in the time of observation changes that occurred during the study period. There is a good post on the Rabbett Run blog about this which give a lot more detail about this issue, but here is an excerpt:

What is it, if anything, that makes rural stations more subject to Tobs bias than urban or suburban ones. Fortunately, Ari Jokimäki, or more precisely Thomas Karl, had already answered that question. In his AMS lecture (video here), Karl pointed out that

The time of the observation also causes a problem for the analysis. Early in the morning temperature usually is lower than in the afternoon. If the observation time of some station changes for example from morning to afternoon, it causes a warming bias to the data of the station in question. This has caused a false urban heat effect.

There is practically no time of observation bias in urban-based stations which have taken their measurements punctually always at the same time, while in the rural stations the times of observation have changed. The change has usually happened from the afternoon to the morning. This causes a cooling bias in the data of the rural stations. Therefore one must correct for the time of observation bias before one tries to determine the effect of the urban heat island.

Karl shows a comparison between urban and rural stations after the time of observation bias has been corrected, and there’s hardly no difference when the situation of the USA is considered. In the global analysis the rural stations even seem to show slightly more warming than the urban stations. Stations are being classified as urban or rural with assistance of satellite measurements where the amount of light pollution is measured in different areas. Also some other information are being used, such as maps, population statistics, etc.

BTW - the Thomas Karl video linked to in the post was lengthy but excellent - I highly recommend it to laypeople like me.

And:

Thus we now have three reasons, why the technical problems may cause a difference in the trends of the raw data:

1. Time of observation bias stronger in rural stations.

2. More problems due to the UHI in the bad stations.

3. Selection bias (bad/good stations at the end of the period may have been better/worse before)

Sounds like the first two problems can be solved by homogenization. And the third problem is only a problem for this study, but not for the global temperature trend.

[ben4vols]

So what's the verdict?

Weather is weather and humans contribution of CO2 has a small effect.

[donsutherland1]

I think it is still too early to reach a verdict on Watts' draft paper - but there are increasing signs that it is deeply flawed.

...And:

Thus we now have three reasons, why the technical problems may cause a difference in the trends of the raw data:

1. Time of observation bias stronger in rural stations.

2. More problems due to the UHI in the bad stations.

3. Selection bias (bad/good stations at the end of the period may have been better/worse before)

Sounds like the first two problems can be solved by homogenization. And the third problem is only a problem for this study, but not for the global temperature trend.

Thanks Phillip for posting the early reaction to the paper. I reserve judgment, but have reservations about the paper.

I suspect a mixed verdict where some of its conclusions could be sustained through peer review (probably considerations for improving siting-related issues), but its overriding conclusions that the U.S. temperature record cannot be relied on or that warming in the U.S. has been all mut minimal, very likely won't. Too much work has been done in the quality control and homogenization--much of which is based on credible peer-reviewed science--for the record to be anywhere near as flawed as Watts suggests. Independent research by BEST also has largely supported the validity of multiple existing temperature data sets and the BEST study reviewed far more stations than Watts did. Too many non-temperature proxies for warming related to changing plant hardiness zones to shifting flora suggest warming that is more significant than what Watts finds has occurred.

[donsutherland1]

...humans contribution of CO2 has a small effect.

Two points:

1) If human activity led to zero CO₂ emissions, annual CO₂ emissions would not have exceeded annual absorption. Instead, the atmospheric concentration of CO₂ increased by an average of 11,700 million metric tons per year during the 1990s. Were human emissions about 51% less per year than what they were, there would still have been a balance between annual emissions and absorption. The reality is that human activities have made the marginal difference in tipping a balanced natural emissions-absorption situation into the unbalanced one that has led to a steady increase in the atmospheric concentration of CO₂.

2) CO₂ has a positive radiative forcing. Hence, the rising atmospheric concentration of CO₂ has an impact consistent with its radiative forcing and the climate sensitivity related to that forcing has been estimated. In contrast, no credible research shows zero climate sensitivity to the growing atmospheric concentration of CO₂.

[ben4vols]

2) CO₂ has a positive radiative forcing. Hence, the rising atmospheric concentration of CO₂ has an impact consistent with its radiative forcing and the climate sensitivity related to that forcing has been estimated. In contrast, no credible research shows zero climate sensitivity to the growing atmospheric concentration of CO₂.

I didn't say zero climate sensitivity but the climate sensitivity is less than the range given by IPCC. Thus human contribution of CO2 has had a small effect on climate.

[PhillipS]

I didn't say zero climate sensitivity but the climate sensitivity is less than the range given by IPCC. Thus human contribution of CO2 has had a small effect on climate.

Please provide a link to peer-reviewed research that supports your assertions. .

[Entropy]

I created a chart of U.S. temperature departure from four major global temperature data sets for the period 1979 to 2008 (i.e. the timeframe Anthony looked at in this study). The departures given are based on the 1981-2010 mean for each respective dataset. The trends for the period ranged from +0.25C/decade from the UAH satellite analysis to +0.33C/decade from the NCDC. The BEST analysis came up with a trend of +0.30C/decade, which is in line with the values reported by GISS (+0.31) and NCDC (+0.33). This is significant because BEST used nearly 10,000 stations in the U.S., as opposed to 1,221 stations in the USHCN network. The BEST approach also differed from existing temperature datasets with its novel approach to the problem of site moves and instrument changes. Rather than adjust for those changes, the BEST analysis treats any such change as creating a new station and ending an existing station. The only adjustment employed by BEST was a regression to eliminate data outliers, which may be caused by urbanization or undocumented site moves or instrument changes.

[Msalgado]

Weather is weather and humans contribution of CO2 has a small effect.

Two points:

1) If human activity led to zero CO₂ emissions, annual CO₂ emissions would not have exceeded annual absorption. Instead, the atmospheric concentration of CO₂ increased by an average of 11,700 million metric tons per year during the 1990s. Were human emissions about 51% less per year than what they were, there would still have been a balance between annual emissions and absorption. The reality is that human activities have made the marginal difference in tipping a balanced natural emissions-absorption situation into the unbalanced one that has led to a steady increase in the atmospheric concentration of CO₂.

2) CO₂ has a positive radiative forcing. Hence, the rising atmospheric concentration of CO₂ has an impact consistent with its radiative forcing and the climate sensitivity related to that forcing has been estimated. In contrast, no credible research shows zero climate sensitivity to the growing atmospheric concentration of CO₂.

I didn't say zero climate sensitivity but the climate sensitivity is less than the range given by IPCC. Thus human contribution of CO2 has had a small effect on climate.

Please provide a link to peer-reviewed research that supports your assertions. .

Because there aren't enough threads for this in the forum? Please DO NOT provide a study and Please DO NOT derail this thread any further. This one's pretty interesting, IMO.

[donsutherland1]

The Skeptical Science blog has posted a critique of the Watts paper. The critique can be found here:

http://www.skepticalscience.com/watts_new_paper_critique.html

[Msalgado]

So basically the "why" is that no adjustment beats the peer reviewed adjustment? I doubt that's going to fly.

[Entropy]

So basically the "why" is that no adjustment beats the peer reviewed adjustment? I doubt that's going to fly.

More like throw out the 7000+ stations used in the BEST analysis, throw out the 1221 stations used in USHCN, and use only the 100 or so stations identified by Watts as the best, and then adjust all of the other data to match the trend shown by those sites.

[ben4vols]

More like throw out the 7000+ stations used in the BEST analysis, throw out the 1221 stations used in USHCN, and use only the 100 or so stations identified by Watts as the best, and then adjust all of the other data to match the trend shown by those sites.

Or throw out 21 out of 23 Arctic stations and adjust them in the same fashion. Then take those adjusted temps and apply them across the Arctic as a whole.

[WeatherRusty]

Or throw out 21 out of 23 Arctic stations and adjust them in the same fashion. Then take those adjusted temps and apply them across the Arctic as a whole.

What are the alternatives?

Use them all raw as is with known issues? Is not bad data worse than no data at all?

Throw them all out. Assuming the arctic to be equal to the remainer of the Earth as a whole which it most certainly is not?

[ben4vols]

Weather is weather and humans contribution of CO2 has a small effect.

Good stuff from Dr. Christy in his testimony in front of the Senate.

[WeatherRusty]

Good stuff from Dr. Christy in his testimony in front of the Senate.

Brilliant observations by Christy....Nations can not prosper without energy and CO2 is plant food. I suppose he had to dumb down his rhetoric considering the audience he was speaking to.

[donsutherland1]

Dr. Roger Pielke Sr. Is strongly praising the new Watts et. al paper FWIW

http://pielkeclimate...re-trends-by-w/

It appears that Pielke has dialed back his praise now that the time of observation issue has arisen.

http://pielkeclimatesci.wordpress.com/2012/07/31/summary-of-two-game-changing-papers-watts-et-al-2012-and-mcnider-et-al-2012/