Global warming - I don't get it?

[Graeme M]

Can someone tell me where the reference point is that they measure the rising sea levels against ?
Just wondering.

Simple question surely someone knows where the reference point is.

While I can't answer in detail, the process works more or less like this as I understand it. A local station datum is set with reference to a local benchmark. The benchmark is obtained geodesically, while the datum is a calculated level with respect to the benchmark. This datum is set to be lower than lowest possible water. Tidal means (eg mean higher high water, or mean low water) are calculated over an epoch, usually 19 years, and referenced to the station datum. The benchmark is usually significantly above highest high water (most often at some particular point on land near to the coast).

If the most recent epoch is from 1983 to 2001 for example, then the mean sea level (MSL) tidal datum would be that derived by averaged measurements over that period (as compared to the station datum). Current MSL (and therefore MSL trends over time) can be calculated by averaging local tidal values and comparing them to the station datum.

That's relative local sea level. These days satellites (eg TOPEX/Poseidon) measure MSL globally. I think they do this by averaging sea surface fluctuations as measured and comparing that to theoretical surfaces that are derived mathematically (ie a reference ellipsoid).

[Graeme M]

Just to clarify, local sea levels are derived from measurements against a local datum point. That's a relative value as the land (which is used to establish the datum) might be rising or falling.

Global mean sea level is derived via satellites. They measure the sea surface using radar and compare that to a mathematically idealised version of the earth (in other words, they establish the difference between the surface they measure and a mathematically derived datum). This is therefore an absolute value.

[Mick D]

Source; US EPA
http://www3.epa.gov/climatechange/science/indicators/oceans/sea-level.html



The rise is slow.
This why I don't see a need to make a panicked move in my remaining life time.
Will my real estate be worth anything in future generations?

I don't see an issue.
The value of my investment is as a great place to live now. Not long after I am dead.

[pokey]

So does this mean we are getting the great inland sea back in Australia?  that would be good for fishing but if it gets warmer that means the Crocs will start coming down the coast and thats not so good. But we could grow Bananas in Tasmania so thats good but maybe the price of Akubras would go up and thats bad.

 its happened before and it will happen again. Were just here for a short time when you think about just how long this world has been around and its been changing ever since then for reasons like giant asteroids and volcanic eruptions to termite farts.

i agree its getting warmer and sea levels are rising but what about if thats just part of the cycle and human involvement have got stuff all to do with any of that???

[oldyzman]

so 8 inches in 100 years, - no prob, Nepean raceway would be at least 10 ft above sea level. we still have 1200 years of racing.
Brett

[Mick D]

So does this mean we are getting the great inland sea back in Australia?  that would be good for fishing but if it gets warmer that means the Crocs will start coming down the coast and thats not so good. But we could grow Bananas in Tasmania so thats good but maybe the price of Akubras would go up and thats bad.

 

Looks like the joint might be flat-linning anyhow Pokey


Or some may choose to look at the flat line as what was a long period of stability
The little spike rise now might just be because we are getting rid of the last couple or ice cubes.
Better to get it over with  

What I find as a fascinating stat, is a 3 billion population in 1960 to tripple to 9 billion 88 years latter, wow.


There should be no talk of financial doom and gloom.
Commerce should have a major time and opportunity ahead of it growth wise. In a very short period.
Lots of needs to be met. Lots of needs to be produced!
Only global mismanagement could blow that opportunity.
Pretty sad as a species if the greed of the few cannot embrace prosperity for all instead.

[pokey]

Somehow vintage jetskis dont seem to have the same appeal and i dont even know if suzuki make one. Make a mighty fine outboard though and they use a lot of the same engine parts as my tRusty 185's so Im okay with that but they designate the engines as DT and thats too close to Yamaha and I cant see me ever owning another yamaha.One was more than enough.

Well looks like i will have to pour my entire life savings of $7.55 into further developing a Croc repellant if they are going to come south. So far its working. Ive not seen or heard a single one in the yard in over a week. Thats if you dont count me to talking to the ex on the phone. originally it was developed for mother in laws but i got sidetracked by a solicitor and an empty bank account.




 i wonder if robbie madison will teach me how to do this?

[Mike52]

Don't get me wrong Mick D and Graeme I actually believe that we are trashing the place and the result will be ugly.
But what pisses me is the uneducated bullshit served to the public.

The reason I asked about the reference point is ,as Graeme picked , because there isn't one.
The whole surface of the earth is constantly moving.

Here's something that came out just the other day .

" The Arctic ice is melting at a rapid rate "
My problem with this piece of scaremongering is that " Arctic Ice " is SEA ice.
When SEA ice melts the sea level goes DOWN not up. Most of us learn't this at school and have forgotten it.

If the Antartic ice was melting then we would have a problem because it mainly rests on dirt so the sea level would go up but Antartic ice is increasing so the sea level is again going down.
 We had one a while back where the "something [ don't remember the name ] " shelf in the Antartic had broken off , shock horror , sea ice again I'm sorry , so the level will go down when it melts.
When icebergs melt the sea level goes down.

MickD put up a chart showing the population increase on earth showing an increase of 5 billion people since 1900.
Consider this , the human body is 60-65% water and the amount of water in a 50kg person is 30ltr so there's another 150 billion liters of water removed from the system.

If you look at a global sea level map you will find that the level is going DOWN around Indonesia.
But again referring back to my school days surely water finds it's own level.
Could it be that the land is rising due to the shifting of the plates?
How could satellite measurements show the sea level going down in one place and going up next door.
Sorry guys , don't make sense.
Could it be that the EXPERTS are actually relying on computer modeling instead of reality ?

Anyhow I went riding and that fixed me for a while so I'm going again.
I also pulled my two stroke husky's out of the shed and fired them up and took a fang up and down the yard , joy , youngsters don't know what their missing.

[Graeme M]

Mike, sea level is a complex thing indeed. I've done a lot of reading about it, but only understand it superficially. You are right that local sea level changes are relative and can be up or down. Some places for example due to a variety of factors have a falling local sea level. Others find it rising. Around Australia, generally, it's not much on the east coast but more on the west coast. Mostly due to local changes in land levels. Sea level rise generally has done nothing much at all.

Take the pacific islands that everyone calls out as the poster child for sea level rise impacts. In fact, not a helluva lot is going on there due to sea level. Much is due to over population, poor local practices, and simple hype.  Yes, the sea level has been inexorably rising for centuries and the place is very low and one day it will be a problem.  But it's not so much from the impacts of climate change.

Generally speaking, the argument is that melting glacial ice and warming of the oceans causes sea level rise. However there is precious little evidence for any acceleration in sea level rise rates over the past century.

As well, you can simply observe local effects. Are there any? Not really. An 8 inch rise in mean sea level over a century is pretty much unnoticeable in the real world. And in many cases it's not even that much. Yes, in some places in the world it has been more than that, but on the whole, not much is going on.

Sea level rise will only be a problem if for some reason, things change dramatically. The argument is, that 'some reason' will be global warming. But again, it would have to be some major event such as a melting of the Antarctic or Greenland ice sheets.

[Mike52]

Watched a Doco on sea level rise and how it affected 1 small Pacific Island.
It was very interesting.
This island is sand on top of coral.
First up they mentioned that they were now rationing fresh water as the well was running dry.
Then the speaker said that it did not rain there as much as it used too.
Then he showed the places where the sea level had risen.
Then he blamed you and me for our first world lifestyle and said we should compensate the residents for the damage we had caused by making the sea rise.

My problem with this Doco is as follows and anyone who has spent time on a sand island will understand.
[ I have been to Fraser/Stradbroke Islands many times and was lucky enough to grow up partially on Moreton Island all here in Qld.
Under all these islands is a bubble of fresh water that does not mix with the sea and you can see this by just walking along the beach because it runs out when it gets over full.
These islands also have lakes that are above sea level.
This water is brackish because of the vegetation in the sand.
The sand and vegetation act as a sponge trapping the fresh water.

So , if you pump the well dry what happens ?
The bloody sand collapses and the sea rushes in.
These people have caused their own nightmare and want to blame someone else for it and we are the only ones that will listen.

Anyhow that's enough from me , hopefully I've caused some to research instead of just believing.
This is my XR400 and I'm off for a 5 day ride no doubt causing massive amounts of damage to the environment
.
 

[Mick D]

Yeah, I am over too. Though I near pissed myself when I read oldyzman's and then Pokey's reply
I have anchored for shelter near the wrecks at Moreten, a beautiful place and a beautiful time in my life.
What a great adventure you are heading into in the next five days Mike


Enjoy and bring us back some pics, cheers.

[Mike52]

Never been game to put my adventures up on here Mick. Afraid of offending someone by posting away from the general theme.

[FAT-TOY]

    I have been thinking about this lack of a reference point.  So after discussing it with my 11 year old grandson he and I are going up to Port Stephens on saturday and we are going to push a stick into the sand at the high water mark.  Then in 50 years time he will go back and see how far the water is up the stick.
                   Zane

[FourstrokeForever]

At last someone is making sense..... Mick going for a ride to enjoy the great outdoors of Australia.
Enjoy Mick 

[Lozza]

Burying the head in the sand is what got us to this point. Saying it's all perfectly OK that dirt poor people can get "culled" in a natural disaster is disgraceful.

And exactly what point are we at now? Have you noticed more of your neighbours dropping dead from changes to the climate? Have they not been able to work because of weather changes? 

If i had built a new house a few years ago i'd be more concerned with the extra 9% i had to pay because of this scaremongering associated with this global warming BS

In 92 the world agreed on the science and the trends. Nearly 25 yrs later when emissions have kept rising efforts to curb the use of fossil fuels get knobbled. That is a definition of head in the sand. As big Arnie said even if you don't believe in Global Warming would you be happy to be locked a room with a car with a petrol diesel or lpg engine running or a room with a car with an electric engine running.