Monday, December 17, 2018

Understanding Climate Data made easy

As a full service climate skeptic blog, I chew on a lot of the science so I can present what's going on in an easy to digest manner.  This leads me into the actual temperature data sets pretty regularly which quite frankly is where the action is.  When you actually look at the data it becomes immediately clear that the science is anything but settled.  The planet may be warming, but if so there are some very unexpected things that remain unexplained.  To me, this is the biggest source of skepticism, and it's a skepticism that's entirely justified.

As a starting point, here's a good discussion about temperature measurements.  It's a bit thick going if you're not a science nerd like I am, but let me boil this down for you.  The weather stations that feed data into the climate databases.  For the USA - and actually most of the world, really - this is the Global Climate Historical Network, or GHCN.  You can get you a copy here.

The weather stations daily record two items of primary interest to us:

  • TMax, the highest temperature recorded on each day, and
  • TMin, the lowest temperature recorded on each day.

This actually makes a lot of sense, and there's a ton of analysis of this data which gives us daily average temperature and the like.  So far, so good.

The biggest fly in the ointment (as I've repeatedly complained about) are the adjustments made to the data after it was recorded.  This is done for many reasons: a change in equipment to a model that reads a slightly different temperature, a station movement to a hotter or cooler location, a change in the time of day when the readings were taken, and a bunch of others.  If you're talking about satellite data one of the adjustments is for orbital decay and another is for relativistic effects which is pretty cool.

I won't talk about adjustments here because I've beaten that horse to death.  If you're interested, a starting point is my Layman's Guide to the science of global warming on the right hand sidebar of this blog.  For now we'll just leave it as my opinion is that the most or all of the warming we've seen in the last 100 years are do to adjustments (i.e. it's not in the actual data as recorded from the weather stations) and a bunch of these adjustments are very poorly justified.

So let's talk about data that are not adjusted, namely temperature records.  These by definition are unadjusted TMax and TMin readings.  I'm interested in these because if you're suspicious of the adjustments, you can avoid them entirely by just looking at records.  Wikipedia has an interesting page of record high and low temperatures for each of the 50 US States here.

Now it's Wikipedia, and we've seen over and over again.  But facts are stubborn things, and record high or low temperatures are stubborn facts.  So let's take a look at them, as shown on the Wikipedia page and use this to figure out what we think may be going on regarding global warming.  After all, we're continually told that the world is rapidly warming and that things are a crisis.  You'd expect to see this in new temperature records being set.

Actually, we're not.

In the last 50 years (since 1968), only nine states have set high temperature records.  41 states set high temperature records in the years before that (the records date back to 1888, when Colorado had a record hot day).  The highest recorded temperature in any of the 50 states was set in 1913 in California.

The sneaky thing that Wikipedia does on this page is that if a state tied a record, the latest date is shown.  This adds another 3 states to the last 50 years, but I am not including them in the 9.  The reason is that the proposition that we're testing is that the climate is warming - getting warmer over time.  If it is as warm as it had been then that's not evidence for warming.  Wikipedia is sneaky here, not showing the original  date that the record was set (and I'm too lazy to dig this up) so for our analysis today we are going to ignore these three data points.

So we see 9 states (18% of the total) setting high records in the last 50 years. 41 states (82% of the total) haven't seen record high temperatures in the period we've been told is an accelerating and hotter climate.  You would expect to see a lot more states - another 15 or so setting recent high temperature records.  Weird, huh?  It's almost like if you remove the adjustments to the temperature data, you don't see accelerating warming.

In fact, we may be seeing the opposite.  If you look at record low temperatures you see a lot going on in the most recent years.  15 states have set record low temperatures in the last 50 years (once again ignoring dates listed with an asterisk which tells us the year that the previous low record was tied).  This is only 30% of the total, but that's basically twice as many as set record high temperatures.

So the unadjusted data tell a different story than the adjusted data.  While inconclusive, there's actually more data showing cooling than show warming.  At the very least, the proposition that the climate is unusually warm and getting warmer is not supported.


Now the establishment science story is that average TMin has been increasing over time, while average TMax has not been increasing much (looking at adjusted data).  Left unexplained is how increasing carbon dioxide in the atmosphere increases average low temperatures while not increasing average high temperatures.  Also left unexplained is how increasing average low temperatures (without increasing average high temperatures) will lead to ecological disaster.  Maybe it could, but it's not at all obvious how this would happen.

It's also not explained why Urban Heat Island (UHI) doesn't explain the higher average low temperatures (TMin).  UHI is where a weather station that used to be in a nice grassy field is now in the middle of an airport, surrounded by tarmac and blasted with jetwash.  It's surprising just how many weather stations are not sited to accurate data collection norms - only 8% of GCHN stations are accurate withing 1°C.

You'd think that if the science were as settled as everyone tells us that evidence supporting global warming would be falling off the trees and piled on every street corner.  Instead, we see evidence against is kind of everywhere.  Hmmmm.

7 comments:

Beans said...

The agricultural evidence over the last 100 years in Florida definitely points towards a cooling world. Once orange groves thrived as far north as the Georgia border, but now, after years and years of freezing winters and destroyed groves has pushed even the vaunted Indian River Citrus from around Cape Canaveral and Merritt Island to south of Brevard County.

Global warming, sure...

And if sea levels have been rising, my mom's house in Satellite Beach, just south of the Cape, would have been underwater years ago. Last year, I checked and still didn't need a snorkel to see her.

Yet, when you talk to the (dumb)masses about this, they just look at you like you've grown a 2nd head or something.

And thanks for keeping the facts rolling.

Old NFO said...

Thanks for the explanation. Yours mimics what I'm hearing from the real climatologists I know.

Howard Brewi said...

I am mostly in agreement with most of what you have been saying. Since one of my sons is gungho global warming I keep getting references to things like reduction in shore ice in the Alaskan Arctic, unusually warm temperatures in the Berring sea and extreme heat in Australia. We live in interior Alaska and have had exceptionally warm weather this year compared with what we saw thirty years ago. I don't buy human based air polution type warming but what give with huge shift in the jet stream that seems to have caused these anomillies?

Beans said...

Howard, if the Arctic Ice was constantly reducing, then why have the Russians made a hurried investment in updating their icebreaker fleet, including adding more hulls.

Seems they are far more worried about global cooling than global warming.

As to warming trends in Alaska, there are some correlations between regional warming and increased volcanic activity (which includes fault activity.) So, since the Ring of Fire has been heating up in the last 30 years even though the actual Arctic Ice has been getting deeper...

Howard Brewi said...

Beans I think the problem is a lot more complicated. As I understand it ice has increased on the Atlantic side of the arctic blamed on the increased fresh water from Greenland melt. They also blame the slowing of the North Atlantic drift on this. The Berring Sea and much of the coast in the Barrow area have much less ice. Two winters ago my daughter was teaching in the Pribilovs and the people out there were apalled at the lack of ice. I know some ice melt in one side of the Antartic continent can be blamed on volcanic activity but the general wide spread warming trend and water temp rise does not seem to follow fron any patern in volcanic activity. There are also warm water "blobs" in the Gulf ofAlasla that are affecting Salmon returns. I have heard explanations of cooling in the lower 48 and the above mentioned changes up here as related to the shift of the jet stream. Possibly the cloud forming effects of increased radiation from the solar minimum that has been postulated is a partial cause. We have certainly had much more cloud cover in our area than past years. When it is 40 below it is usually clear as a bell.

Borepatch said...

Howard, if the sea ice is shrinking, then why are ships getting stuck in the ice more often? I post about this regularly, for example:

https://borepatch.blogspot.com/2018/09/climate-change-ship-of-fools.html

And I believe that the Canadian Coast Guard is also upgrading their icebreakers. Not definitive, of course, but relates to my point that the science is not so clear and settled as we are so often smugly told.

Howard Brewi said...

As I said , ice is expanding on the Atlantic (Canadian) side of the arctic. As I understood it twenty or so years ago the melting of a certain amount of Greenland ice puts a layer of fresh water on the surface which can expand the surface ice. At the same time they expected the effect on deep convections to slow the North Atlantic drift (northern extension of the Gulf Stream). Back when the coming ice age predictions were in the news this was seen as a mechanism to eventually start the cooling of Europe and the East Coast of North America. My current understanding is that the North Atlantic drift is almost stopped! Meanwhile on the Pacific side the last couple of winters have left the Berring Sea and the Coast of Northern Alaska with an EXTREME reduction in ice. This is a FACT! I have seen it blamed on a massive shift in in the jet stream also causing "polar vortex" type weather patterns that have caused the freezes in the north east and Europe extending into Asia the last two or three winters. What I would like to know is what mechanism has caused this massive shift of the jet stream and would therefore help explain these facts.