[jedrider]

In the future it will be 100% and we mean it, now!

[Nefarious]

The argument someone was trying to make here that it is generally getting hotter....what is the best data to look at then? Nightime? no. Average over the day? no. The best is maximum temperature of the day and that data say no it isn't getting hotter compared to the thirties. How do you measure a hot day? Do you say well it was really hot this afternoon but it was cool las night so I guess on average it wasn't that hot?

Growing Degree Days
http://www.greencastonline.com/growing-degree-days/home

from January 28, 2018 to November 26, 2018 My location had 9013.5 GDD
from January 28, 2019 to November 26, 2019 My location had 5534 GDD
Most of the US has had a substantial drop in GDD from last year
What is a GDD ? https://en.wikipedia.org/wiki/Growing_degree-day

[rockdoc123]

Must have been Phoenix or Las Vegas. I would like to see some actual weather reports of so many nearly consecutive hot weather days. Still doesn't demonstrate a cooling trend because we all know that it has NOT been cooling since then.

As I said all of the data is available at NOAA. You can dig down to the State level quite easily or you can spend more time looking for individual long run stations. If you don't believe the plot go an make one yourself. As I said NOAA is under maintenance this week so can't update anything.

I never claimed there was cooling did I? What I said simply is that it isn't getting hotter (more high temperatures) as of late compared to the thirties. If you dig around AMS has reports from the thirties and it was pretty devastating temperatures. As an example, they point to 40 consecutive days in 1934 where somewhere in the US recorded a temperature of 100 degrees or higher. That same year Fort Smith saw 53 days of high temperatures above 100. Imagine that sort of heat with no air conditioning. Most don't seem to realize that the general increase in average temperature is because of an increase in minimum temperature, not maximum temperature. There can be a host of reasons for that pattern unrelated to CO2.

Growing Degree Days

irrelevant to the discussion of heatwaves and maximum temperatures. Growing degree days are simply days that are warm enough for seeds to germinate. That actually isn't all that warm and you would expect this to vary quite a bit year on year.

[Nefarious]

If it was getting hotter "hottest year ever" GDD should be on the rise not falling.
A GDD is a measure of heat

[rockdoc123]

If it was getting hotter "hottest year ever" GDD should be on the rise not falling.
A GDD is a measure of heat

all in the definition I guess. Most I have seen reference the hottest years by number of days above a certain high temperature or the number of high-temperature records set. You could have a year where the number of growing days is high but that because warmer days are added in the spring or fall and maximum temperatures were nowhere near records. Alternatively, you could have a year with a number of high temperature records but a cold spring and fall resulting in lowered GDD.

[jedrider]

Rockdoc, that looks like a 'bogus' graph, but it probably is a graph of something, maybe, something significant.

I am always troubled by the recollection that the depression years also coincided with the dust bowl. A sign of things to come.

[rockdoc123]

Rockdoc, that looks like a 'bogus' graph, but it probably is a graph of something, maybe, something significant.

that sort of comment is what is bogus unless you follow it up with data that supports your argument. The graph simply plots data from NOAA which collects it from station data archives across the US and the world. As I said the NOAA site is down this week for annual maitenance but when that is done you can search to your hearts content.

[Plantagenet]

A new study published in NATURE identifies nine "active" tipping points...i.e. places where the warming climate may cause major problems in the near future.

nine "tipping points" around the globe

The Nine active tipping points:

Arctic sea ice
Greenland ice sheet
Boreal forests
Permafrost
Atlantic Meridional Overturning Circulation
Amazon rainforest
Warm-water corals
West Antarctic Ice Sheet
Parts of East Antarctica


A traditional Chinese curse goes: "May you live in interesting times."

Cheers!

[Keith_McClary]

It is data directly from NOAA .

Is it a simple average of all the stations for each year, as Tamino claims? (Without allowance for area density of stations?)

[rockdoc123]

The raw data is available at NOAA but it amalgamates data from the global network GHCN which is the dataset that almost all of the main temperature indices (HadCrut, Best etc) use in one manner or another. The calculation of average is done through a gridding process on their computers and is not a simple average as it takes into account all of the stations which recorded daily highs and lows and have had corrections applied to them. Those overlapping grids are then averaged in the NOAA dataset by State or Region etc. The argument can be made that this method ignores distance between stations but for the US this is much less important due to the closeness and vast number of station measurements used. As such the grid chosen is small and the error due to distance affects is much less than it might be where stations are further apart such as parts of South America, Africa and Europe. In those situations, kriging is used by most researchers to arrive at averages. A good explaination of the methodology appears in

Rohde, R et al, 2013. Berkeley Earth Temperature Averaging Process. Geoinfor Geostt: an Overview 2013, 1:2. http://dx.doi.org/10.4172/gigs.1000103

[Plantagenet]

If it was getting hotter "hottest year ever" GDD should be on the rise ....
A GDD is a measure of heat

Yes, but there are peculiarities in the way the GDD is defined that make it totally unsuitable as an accurate measure of global warming.

For instance, the MAXIMUM temperature used in calculating GDD is capped at some value, typically 30°C.

"GDDs ... the maximum temperature is usually capped at 30°C because most plants .... do not grow any faster above that temperature. " ---from Wikipedia

Obviously using a proxy for temperature like GDD with a built-in maximum cap is a silly way to measure how hot it is getting because it cuts off all temperature data from days that go above the pre-set cap, and hence doesn't capture all the actual temperature data showing increasing summer temperatures.

Cheers

[jedrider]

Far more interesting to me is the question: Why did the Great American Dust Bowl happen during the American Great Depression?

Because they were both 'Great'? Or, because of the relative absence of Global Dimming?

[Plantagenet]

Far more interesting to me is the question: Why did the Great American Dust Bowl happen during the American Great Depression?

Because they were both 'Great'? Or, because of the relative absence of Global Dimming?

There was a drought in the 1930s....but it wasn't a particularly severe or long drought. The area had seen worse droughts in the past and not generated huge dust storms. However, the area affected by the "dust bowl" had been homesteaded during the preceding decades, and by the 1930s the native hardy grasses that survive past droughts had been almost entirely replaced with wheat.

Unfortunately, wheat couldn't survive the 1930s drought and died, and the bare soil was exposed to the wind and the wind elutriated the dust and generated the huge dust storms of the dust bowl.

lamont doherty earth observatory: dust bowl



Cheers!

[jedrider]

True, about the 'cause' of the dust bowl, but higher than usual temperatures probably didn't help either nor instability in climate as we are seeing now.

[Keith_McClary]

not a simple average

Maybe when NOAA is up again you can give a source for your graph.

[dissident]

The trend pictures posted by the rock technician are fraudulent concoctions.

[rockdoc123]

The trend pictures posted by the rock technician are fraudulent concoctions.

Horse crap. This tells me you are in fact not a climate scientist. Anyone who actually spends time in that field would understand the difference between maximum temperature and average temperature.....except apparently you.

So I post plots showing trends in the US in daily maximum temperature and then trends in the number of days the US saw temperatures somewhere above 100 C as a response to the claim that there are more heat waves or it is getting hotter in the US (i.e. maximum temperature) and your response is to show us a plot of global averaged surface temperatures and satellite temperatures? Are you that stupid as to not realize this is a huge red herring argument? Missed that day in school where they taught logic?

[clif]

The difference between the two graphs is

croc docs graph are JUST the US

Where as dissident's graph is the whole planet......

something croc doc seems to hope we miss,

I wonder why

[rockdoc123]

The difference between the two graphs is

croc docs graph are JUST the US

Where as dissident's graph is the whole planet......

something croc doc seems to hope we miss,

I wonder why

apparently you are seriously illiterate which has lead to this moronic comment. I said in the very post before yours that my post was to address the fact someone claimed it was getting warmer (more hot days) in the US and that was made very clear in my original post. It is quite clear from the graphs it is the US. It is also clear it is maximum temperature and days above 100 C. I went to great lengths in answer to someone suggesting Tamino had debunked that approach to point out that in order to discuss heat waves and extreme temperatures (what this discussion was about all along) you need to reference maximum daily temperature, not daily average temperature which is meaningless in that context. And it is certainly meaningless to attempt to discuss US heatwaves by showing a plot of average daily temperature from the globe as Dissident did.
Do you not actually understand that extremely simple logic?

[clif]

That global warming is real scientifically proven and the CO2 released by human activity is the major reason that it is happening;

Yes. I understand that.