Dunedin to be flooded

April 13th, 2010 at 4:00 pm by David Farrar

Dunedin could face some stark choices by the end of the century, with sea-level rise expected to force either the retreat from, or complete evacuation of, South Dunedin, St Kilda and St Clair.

Dunedin will just be one giant swimming pool!

A report on climate change and its effect on Dunedin includes a prediction of an upper level for sea-level rise of 1.6m by 2090.

Okay that is 1600 mm over 80 years which is an average rise of 20 mm a year.

Predicting the upper range for sea-level rise was also “problematic”, he said, with the most recent Intergovernmental Panel on Climate Change (IPCC) suggesting 0.6m, but more recent research suggesting 1.6m was a more prudent prediction.

I prefer to wait for the IPCC to update their report, rather than have people cherry pick individual more alarmist pieces of research.

The IPCC report said that the likely increase in sex levels was 180 to 590 mm, which is an average rise of 1.8 to 5.9 mm a year – between one tenth and one third of what the ODT story reports.

So how likely is a sea level rise of a massive 20 mm a year?

What has been the rise so far in NZ?

Consequently, sea levels around New Zealand have risen on average 1.8 mm/year over the last 40 years with the total sea level rise over the last century of 0.17 m.

So the rise over the last 100 years has been 1.7 mm a year and last 40 years has been 1.8 mm a year. So that is 10% of the 20 mm Dunedin will be flooded scaremongering.

Now in the last 17 years, sea level rises have been greater – an average 3.1 mm a year. That is consistent with the IPCC 590 mm increase, but still a long way off the 1600 mm talked about in the ODT article.

Also one has to understand that to get an average of 20 mm a year over 80 years, you need quite massive increases in the latter section to make up for the current slower rises.

If you assume a linear increase in the average annual rise, then the amount of annual rise has to increase by 0.45 mm a year. What this means is that by 2020 the rise will be 7 mm/yr, by 2030 12 mm/yr and by 2090 it would be 39 mm/yr.

Is anyone willing to bet money that by 2020 the average sea level rise will be 7 mm/yr?

Tags: Climate Change, Dunedin, ODT

This entry was posted on Tuesday, April 13th, 2010 at 4:00 pm and is filed under NZ Politics. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

57 Responses to “Dunedin to be flooded”

coge (124) Says:
April 13th, 2010 at 4:05 pm
An increase in sex levels?
Vote: 0 0 You need to be logged in to vote
fizzleplug (72) Says:
April 13th, 2010 at 4:06 pm
“The IPCC report said that the likely increase in sex levels was 180 to 590 mm”

Women everywhere rejoice?
Vote: 0 0 You need to be logged in to vote
krazykiwi (9,188) Says:
April 13th, 2010 at 4:18 pm
I prefer to wait for the IPCC to update their report, rather than have people cherry pick individual more alarmist pieces of research.

DPF, If you want alarmist pieces of resaerch then I suggest you use all/any IPCC reports you had get your hands on.
Vote: 0 0 You need to be logged in to vote
Bevan (3,951) Says:
April 13th, 2010 at 4:19 pm
Isnt 0.17m = 17cm, not 1.7mm

Nevermind, didnt read it properly….
Vote: 0 0 You need to be logged in to vote
Sonny Blount (1,753) Says:
April 13th, 2010 at 4:23 pm
The total sea level rise will get to 3 to 4 metres before we are able to conclude that human effects have anything to do with it. This is what the sea level was in the last interglacial, it should get there very slowly but it is nothing to be concerned about until it goes above about 5 metres.
Vote: 0 0 You need to be logged in to vote
Pete George (17,596) Says:
April 13th, 2010 at 4:28 pm
Dunedin will just be one giant swimming pool!

They said the new stadium would be multi purpose.

But, possibly like the ODT, you could be exaggerating – only half of Dunedin is built on land reclaimed from harbour or swamp.

Sonny, a 5 metre rise would not be good for that half of the city.
Vote: 0 0 You need to be logged in to vote
ben (2,366) Says:
April 13th, 2010 at 4:31 pm
Still citing the IPCC as authoritative? I thought those days were behind us.

Cherry picking a report that is itself a result of some heavy cherry picking is not the way to say anything useful about the world. Shame on the ODT.
Vote: 0 0 You need to be logged in to vote
krazykiwi (9,188) Says:
April 13th, 2010 at 4:33 pm
Polly Higgins, the lawyer behind the idea of ecocide*, is on the board of DESERTEC (www.desertec.org). As press releases make clear, “The DESERTEC Foundation is a charitable initiative of the Club of Rome”. Polly Higgins can be seen listed as a board member on this DESERTEC press release.

Perhaps Polly could push for a law against the tide coming in too.

*British campaigner [Polly Higgins] urges UN to accept ‘ecocide’ as international crime
Vote: 0 0 You need to be logged in to vote
CDH (10) Says:
April 13th, 2010 at 4:42 pm
Yes, and Lake Wakatipu’s level can rise and fall 200mm every 26 minutes — and that’s not global warming. Google “Seiche” and stop reading IPCC reports . . .
Vote: 0 0 You need to be logged in to vote
Sonny Blount (1,753) Says:
April 13th, 2010 at 4:48 pm
Sonny, a 5 metre rise would not be good for that half of the city.

I didn’t say it was.

My point is don’t go blaming my lightbulbs and shower if the sea level rises a bit.
Vote: 0 0 You need to be logged in to vote
Pita (322) Says:
April 13th, 2010 at 4:48 pm
This has got to stop…can’t we just tax someone?
Vote: 0 0 You need to be logged in to vote
Rex Widerstrom (4,965) Says:
April 13th, 2010 at 4:49 pm
I think we need to follow Kevin Rudd’s example and make it quite clear that these refugees won’t gain automatic admittance to the North Island, and will in fact be sent for offshore processing. I suggest Australia.
Vote: 0 0 You need to be logged in to vote
Manolo (9,867) Says:
April 13th, 2010 at 4:50 pm
It wouldn’t be a surprise to know the fantastic article has a byline by someone called Nick Smith
Vote: 0 0 You need to be logged in to vote
Murray (8,832) Says:
April 13th, 2010 at 4:53 pm
“I prefer to wait for the IPCC to update their report, rather than have people cherry pick individual more alarmist pieces of research.”

I’ll just wait until the ACTUAL seas level in the Pacific moves thanks. Which it has not done for some considerable time. The islands move certainly, they go up they go down. Thats nothing to do with the actually seas level. I refer you to a mgical little thing we in the hydrographic surveying world call “chart datum”.

Rex if the Pacific is going up then Auckland is in a lot more trouble than Dunedin. Aint no one south of the Bomabay is going to take those refugees.
Vote: 0 0 You need to be logged in to vote
Hagues (711) Says:
April 13th, 2010 at 4:55 pm
Will there still be people living in Dunedin in 80 years anyway?

But seriously I call bullshit on this.
Vote: 0 0 You need to be logged in to vote
Bevan (3,951) Says:
April 13th, 2010 at 4:56 pm
Meh, its just Dunedin.
Vote: 0 0 You need to be logged in to vote
A1kmm (91) Says:
April 13th, 2010 at 5:05 pm
I think that the precautionary principle has to be employed in light of uncertainties of the upper bound of sea-level rises. The 0.58 m figure is the top of a 95% confidence interval, but that only takes into account the uncertainty allowed for in the model, and not the total structural uncertainty.

The Knutti et. al. 2008 review (http://www.geos.ed.ac.uk/contacts/homes/ghegerl/knutti_etal_projections.pdf) is a peer-reviewed review, which included the first author of the 2007 IPCC climate predictions. It notes that the upper bounds of the predictions in the IPCC reports aqre likely to be too low, while the lower bounds are less affected, due to uncertainty which isn’t taken into account in the models.
Vote: 0 0 You need to be logged in to vote
krazykiwi (9,188) Says:
April 13th, 2010 at 5:12 pm
precautionary principle has to be employed in light of uncertainties

Translation: Create and pull the tax levers! Quick!

As for ‘peer-reviewed’, this concept is more than a little sullied recently, mainly in the field of climate scients to be fair. Do you know the peer selection methodology used by Knutti et al? More interesting would be the peer reviewers who had their review material rejected.
Vote: 0 0 You need to be logged in to vote
RightNow (5,357) Says:
April 13th, 2010 at 5:12 pm
I’m hoping for 6 metres in Wellington by the end of the year so I can sell my house as beach-front.
Doesn’t this sea level rise require continued warming though? That’s going to be a bit of a problem for the next couple of decades, maybe I should install a few coal-burners in the house so I can accelerate the warming some more. The new owners will really appreciate it too since we’re in a cooling phase for the next 20-30 years http://en.wikipedia.org/wiki/File:Pdoindex_1900_present.png.
Vote: 0 0 You need to be logged in to vote
jinpy (237) Says:
April 13th, 2010 at 5:21 pm
Totally agree — the upper limits seem unlikely — one could imagine that a particular event might lead to a sudden dramatic increase, such as an ice-shelf melting in the antarctic and allowing glacial melt to run off, but I can’t see that being easily modelled. What contribution does thermal expansion make I wonder?
Vote: 0 0 You need to be logged in to vote
Sonny Blount (1,753) Says:
April 13th, 2010 at 5:27 pm
I think that the precautionary principle has to be employed in light of uncertainties of the upper bound of sea-level rises. The 0.58 m figure is the top of a 95% confidence interval, but that only takes into account the uncertainty allowed for in the model, and not the total structural uncertainty.

If April is colder than March then the precautionary principle should be applied and we should tax your arse until it warms up again.

For heavens sake 0.58m is one tenth of the expected natural sea level rise.
Vote: 0 0 You need to be logged in to vote
jinpy (237) Says:
April 13th, 2010 at 5:36 pm
Interesting graph on the PDO index RightNow, which shows El-Nino like variation in the north pacific. I wouldn’t necessarily install the coal burners though, the PDO index subtracts the global average temperature to take into account warming. The variation shown is on top of the warming.

http://ffden-2.phys.uaf.edu/645fall2003_web.dir/Jason_Amundson/pdoindex.htm
Vote: 0 0 You need to be logged in to vote
ben (2,366) Says:
April 13th, 2010 at 5:40 pm
I think that the precautionary principle has to be employed in light of uncertainties

Be consistent and apply it both ways. The precautionary principle should also be applied to the massive government interventions being used to solve this alleged climate problem. Socialist governments killed 100 million people last century. The small risk of millions of climate deaths is correctly weighed against the small risk of millions of government-induced climate response deaths and the rather larger risk, if ethanol is anything to go by, of the government response actually exacerbating the climate problem and causing even more climate deaths! Be consistent.
Vote: 0 0 You need to be logged in to vote
krazykiwi (9,188) Says:
April 13th, 2010 at 6:02 pm
The Observer, Sunday 11 April 2010:

Climate aid threat to countries that refuse to back Copenhagen accord while developing nations claim they are being offered cash to sign up to climate change deal.

Rich countries have threatened to cut vital aid to the developing nations if they do not back the deal agreed at the UN climate summit in Copenhagen, it has emerged.

The pressure on poor countries to support the US, EU and UK-brokered Copenhagen accord came as 190 countries resumed UN climate talks in Bonn in an atmosphere of mutual suspicion.

“The pressure to back the west has been intense,” said a senior African diplomat. “It was done at a very high level and nothing was written down. It was made very clear by the EU, UK, France and the US that if they did not back them then they would suffer.”

According to other African climate diplomats, threats to cut aid were accompanied by promises of financial support for countries that complied.

“There was definite strong-arming of countries. A lot were left in no doubt that there would be repercussions if they did not associate themselves with the accord,” said Saleemul Huq, of the International Institute for Environment and Development, in London.

Can’t figure this out. Some, ahem, ‘at risk’ nations like Tuvalu and Maldives are convinced that climate alarmism is their ticket to welfare riches (to save them from inexorably rising sea levels.. which have done a no-show so far) and they’d sign their own arses if it created an accounts receivable invoice to ‘rich’ nations. Others must see nothing in it for them, so need to be threatened to sign.
Vote: 0 0 You need to be logged in to vote
petal (697) Says:
April 13th, 2010 at 6:20 pm
A peer reviewed MODELING TOOL.
95% CONFIDENCE LEVEL OF A MODELING TOOL.

How many heads do you have to bang for over a decade to get people to understand that

1. data is hand picked, edited, ignore and manipulated
2. the modeling program is a “guess” by people who are in a best position to guess, but it is still just a guess
3. “peer review” seems to be bandied about as “IT IS THE TRUTH”. No it isn’t. It just means that the peers had a look at it and though you had a pretty good stab at it.
4. there is NO “peer reviewed” data that can lift the man-made warming from the natural background noise of NORMAL CYCLICAL CLIMATE CHANGE.

100 years from now they are going to call this the IGNORANT ages. At a time when we had more tools and more data than ever before in our history, and instead of using them, we used FEAR and POLITICS to fuel CAREERS and GREED.

ARGH.
Vote: 0 0 You need to be logged in to vote
side show bob (3,660) Says:
April 13th, 2010 at 6:20 pm
Dunedin sounds like the ideal location for National Socialist headquarters, sadly I suspect the much heralded sea level rise will be to late and to little to save us from these toss pots.
Vote: 0 0 You need to be logged in to vote
Caleb (463) Says:
April 13th, 2010 at 6:32 pm
does ice have to melt to make the sea level rise?

does this mean that the sea will be colder?

does sea temperature have a bearing on climate?
Vote: 0 0 You need to be logged in to vote
petal (697) Says:
April 13th, 2010 at 6:36 pm
Oh, and by the way, the plural of anecdote is not data.
Vote: 0 0 You need to be logged in to vote
Put it away (2,887) Says:
April 13th, 2010 at 6:39 pm
First one to invent a floating couch is going to make a fortune
Vote: 0 0 You need to be logged in to vote
Pongo (332) Says:
April 13th, 2010 at 6:43 pm
Christchurch is doing the same thing which is probably no surprise. I am more worried about that glacier in the Himalayas melting in 2035, according to the IPCC. Mental as this all sounds to 90% of the population it keeps the politicians happy and I am filled with joy being a benevolent tax and rate payer.
DPF isnt it about time you did a bit of polling on this ETS ? I had a surreal converstaion with someone from the city mission last week who is totally bewildered as to why the Nats are doing this, he understood labour doing it and knew they would pick up funds through the backdoor in exchange for silence but he was expecting the change in government to halt the relentless cost of living increases his clients have endured. Post climategate etc. he is ready to let rip when the ETS hits his clients household expenses.
Vote: 0 0 You need to be logged in to vote
big bruv (11,201) Says:
April 13th, 2010 at 6:53 pm
Dunedin is all Labour anyway, who gives a toss.
Vote: 0 0 You need to be logged in to vote
Steve (3,644) Says:
April 13th, 2010 at 6:54 pm
People live in Dunedin? I thought they just survived
Vote: 0 0 You need to be logged in to vote
big bruv (11,201) Says:
April 13th, 2010 at 7:00 pm
Steve

Dunedin folk are by and large fairly decent, yes they vote Labour but apart from that they seem OK.

Now if we were talking about Christchurch being flooded, well, that would be cause for national celebrations.
Vote: 0 0 You need to be logged in to vote
side show bob (3,660) Says:
April 13th, 2010 at 7:01 pm
Pongo “why are the National Socialists doing this” , simple Pongo, Shonkey promised tax cuts and someone will have to pay. This means you and I. Tax taken in any ETS scheme will not be going to the barbarians in Russia but into your friendly government sludge fund. Nick Smith is the village idiot, to thick to realize his boss and cohorts couldn’t give a flying fuck about the bullshit that is climate change, it’s all about keeping the cash flowing.
Vote: 0 0 You need to be logged in to vote
RightNow (5,357) Says:
April 13th, 2010 at 7:08 pm
It’s Dunedin, won’t they just Get Over It?
Vote: 0 0 You need to be logged in to vote
Pita (322) Says:
April 13th, 2010 at 7:22 pm
There were to be two certainties in life; Death and taxes… now there are three…anthropogenic Global warming (the science is settled)…we caused it so suck it up, we’re gonna pay and that will fix it.

John Key has lost his opportunity, his focus, his cojones, and indeed any moral principal he may have every had…he’s lost my vote but not to the bankrupt wastrels of the Labour party.
Vote: 0 0 You need to be logged in to vote
Viking2 (9,461) Says:
April 13th, 2010 at 7:54 pm
Do you think Southland will go? We could send the skinny double dipper to check it out.

Has anyone noticed the tone of conversations when you mention the National Socialist Party these days. Anyone noticed the tone on Kiwiblog.
Not at all faltering I’d suggest and certainly suggests to me that many are not happy. The tone is reverting to the kind of conversation that persisted in the last years or two of the Clarkist reign.
Apparently the Nats. haven’t noticed yet or are just going to be like Helen and either ignore it or tell us to move on.

Yesterday the rotund little westie was praising the benefit stats reducing, today Lindsay Mitchel tells the truth.
http://lindsaymitchell.blogspot.com/2010/04/benefit-statistics-what-numbers-mean.html

todays news headlines.
Australia business the best for two years.
NZ business confidence on the wain.
And it is. A six week spurt and down she goes.

Uncertainty abounds after 9 long years sitting filling their finger nails and two years of running working parties.
Well I guess Keys got to meet Obama no less. Anyone got any idea how that is going to reduce the list of beneficiaries and paying our bills starting tomorrow?

Oh and yep we are going to be very influential in getting rid of nucs. as well.
Another bunch of KIWI ego’s out of control.

Does the soup kitchen need anymore money for next weeks feed?
Vote: 0 0 You need to be logged in to vote
Ross Nixon (532) Says:
April 13th, 2010 at 8:05 pm
I’ve got good news for all of you that are worried about the sea level.
The so-called 1.6mm rise per year over the past 100 years is an exaggeration. In fact the sea level has been dropping slowly over the last several years now. How low will it go? Well that depends if the global cooling that started around 2002 continues as some astronomers are predicting.
Vote: 0 0 You need to be logged in to vote
Ross Nixon (532) Says:
April 13th, 2010 at 8:11 pm
Here is the Pacific Ocean seal level graph from 1992 to 2008
http://i34.tinypic.com/28hk7j6.jpg (source http://is.gd/bqDAL)
Vote: 0 0 You need to be logged in to vote
Ross Nixon (532) Says:
April 13th, 2010 at 8:24 pm
And a longer article by John Daly, http://is.gd/bqDAL, although a bit dated (2000) shows almost no rise in sea levels in the 30th century. If you don’t want to read the lot, go to the bottom and just read the ‘Conclusion’.
Vote: 0 0 You need to be logged in to vote
fatman43us (165) Says:
April 13th, 2010 at 9:14 pm
Maybe at last Dunedin will see what Planners suggested in 1913, which was a canal through the area in question to simplify entry and exit from their abyssmal harbour.

Better still, scoop the whole population upo and relocate them to oamaru – the climate is so much better!
Vote: 0 0 You need to be logged in to vote
Gooner (995) Says:
April 13th, 2010 at 9:17 pm
Thank goodness for National’s ETS.

Can’t they implement it earlier than July to stop the world from flooding?
Vote: 0 0 You need to be logged in to vote
Guy Fawkes (702) Says:
April 13th, 2010 at 9:52 pm
The whole World will be redeemed from all the problems of AGW by the simple payment of the 4% tax that is the mooted percentage

that needs to be collected to address the 3 Trillion USD overhang in the Global Financial System.

Who would have thought that paying a little extra would have cured all the proposed problems due to Global Catastrophe.

It truly is a Miracle. Climate Change happens. Always has and always will!!
Vote: 0 0 You need to be logged in to vote
expat (3,975) Says:
April 13th, 2010 at 9:58 pm
Please please please flood Dunners, god knows they don’t deserve a Super 14 franchise as all they do is steal other provinces talent.
Vote: 0 0 You need to be logged in to vote
Short Shriveled and Slightly to the Left (722) Says:
April 13th, 2010 at 10:20 pm
I normally let stupid comments be but I just have to say something about this shit…..
“Please please please flood Dunners, god knows they don’t deserve a Super 14 franchise as all they do is steal other provinces talent.”
……
The Highlanders have to draft players because other franchises take their good born-and-bred in Otago or Southland players.
Two examples would be the Hurricanes captain and All Black Hooker, and the Crusaders captain who also just happens to be the All Black captain (who never played top level rugby for Otago and was poached straight out of high school).
Then there’s Justin Marshal, Corey Flynn, Byron Kelleher……

and then when we do ‘steal’ other franchises talent its often only for other franchises to take them once they play well…..
Doug Howlett, Nick Evans, Daniel Bowdon, Chris Smylie, Rico Gear, Kees Meeuws, Josh Blackie………

these are just names off the top of my head
Vote: 0 0 You need to be logged in to vote
fatman43us (165) Says:
April 13th, 2010 at 10:25 pm
“these are just names off the top of my head”

There is really no answer!

Global Warming could yet do us all a favour!!
Vote: 0 0 You need to be logged in to vote
expat (3,975) Says:
April 13th, 2010 at 10:28 pm
Otago: The’ Other NZ Provinces’ development side. And they are still shit.
Vote: 0 0 You need to be logged in to vote
Crusader (164) Says:
April 13th, 2010 at 10:40 pm
# Ross Nixon (355) Says:
April 13th, 2010 at 8:24 pm

And a longer article by John Daly, http://is.gd/bqDAL, although a bit dated (2000) shows almost no rise in sea levels in the 30th century. If you don’t want to read the lot, go to the bottom and just read the ‘Conclusion’.

30th century?
Was that 500 years after Buck Rogers in the 25th Century?
Vote: 0 0 You need to be logged in to vote
mikeysmokes (269) Says:
April 13th, 2010 at 11:15 pm
Whats in Dunedin for this to be of any concern? The people of Dunedin and Tuvalu can just move to Crimechurch
Vote: 0 0 You need to be logged in to vote
Chicken Little (773) Says:
April 14th, 2010 at 7:10 am
If you can – Stop paying taxes. Stop funding these political morons.

Civil disobedience seems to be the only answer, otherwise we are just ignored.

The ETS is nothing more than stealing from the population – we need to start treating National and friends like we would any other thief.
Vote: 0 0 You need to be logged in to vote
barry (1,317) Says:
April 14th, 2010 at 7:41 am
Anyone who believes the IPCC stuff needs help – lots of it.

Climate is changing, always has, always will. Theres no evidence that human activity is causing climate change (yes there are some unchecked conclusions being jumped to – but no proof in the real sense). Even Jones form the East Anglian CCU recently admitted that the actual measured increase is less than the margin of error – but I bet he still is happy to take the money for frightening everyone.

Even if sea levels rise due to decreased water vapour in the atmosphere (the water has to go somewhere – and the only place is the sea) – it will take place very slowly and the residents of Dunedin need not worry for many decades yet – by which time they will have had probably 200 years of warning.
Vote: 0 0 You need to be logged in to vote
Manolo (9,867) Says:
April 14th, 2010 at 8:19 am
“The ETS is nothing more than stealing from the population..”

Hear, hear. Yes, we’re governed by a kleptocracy, with its chiefs being Nick Smith and empty-suit Key.
Vote: 0 0 You need to be logged in to vote
jinpy (237) Says:
April 14th, 2010 at 8:59 am
# Ross Nixon (355) Says:
April 13th, 2010 at 8:05 pm

>I’ve got good news for all of you that are worried about the sea level.
>The so-called 1.6mm rise per year over the past 100 years is an exaggeration. In fact the sea level has been dropping >slowly over the last several years now. How low will it go? Well that depends if the global cooling that started around 2002 >continues as some astronomers are predicting.

I’m not sure what you’re playing at Nixon, is this ‘disinformation-gate’? I checked out your reference and noted the following:

“Figure 1 shows the Global Sea Level for the period of December 1992 to September 2008. Global Sea Level appears to have risen at a reasonably constant rate until mid-2005, when the rate of rise decreased.”

It is the ‘rate of rise’ that has decreased not the actual sea level.
Vote: 0 0 You need to be logged in to vote
Murray (8,832) Says:
April 14th, 2010 at 10:28 am
We can change the weather with a tax!

People have not evoloved at all, in fact i suspect as a race we are just getting more stupid. At least cavemen we able to live without the media and reality TV.
Vote: 0 0 You need to be logged in to vote
Dazzaman (1,007) Says:
April 14th, 2010 at 10:38 am
Dun-eh-dun is sinking…shite rugby team, shite weather, just shite…..is it the Detroit of NZ? Or are we really talking about Christchurch
Vote: 0 0 You need to be logged in to vote
Dirty Rat (504) Says:
April 14th, 2010 at 10:58 am
Yup
Dump the Highlanders from the $$uper Dooper $$ 14

They are a disgrace

BTW, In light of the good work that Mr Key and Mr Biden are up to, I once hope that Nuclear Testing can soon begin in Fendleton
Vote: 0 0 You need to be logged in to vote
jinpy (237) Says:
April 14th, 2010 at 1:25 pm
Caleb (158) Says:
April 13th, 2010 at 6:32 pm

Here’s my go at your questions:

>does ice have to melt to make the sea level rise?
No, thermal expansion alone would lead to some sea-level rise, but the point is that warming will lead to melting ice, leading to sea level rise (if the ice is land based, sea-ice melting does not add to sea level)

>does this mean that the sea will be colder?
I think thats a fair assumption in surface regions close to the ice and may play a global effect. Overall, the sea will also experience warming from the greenhouse effect

>does sea temperature have a bearing on climate?
Very definitely, that’s why coastal towns in temperate zones can be warmer or cooler than inland locations, in these places the sea acts to keep the weather warm (or cool). The quality of NZ summers depends on ocean currents (El Nino, La Nina) and where the water comes from. Temperature has an effect on ocean circulation. One theory is that global warming may slow down certain ocean currents and actually lead to cooling in certain regions (i.e the UK becoming as cold as Northern Europe). These projections are far from proven however.

The difficulty in the whole climate change issue is the myriad of factors that affect weather — ocean/land/atmospheric temperatures, greenhouse gases (these definitely exist), radiation from the sun (it varies), rate of evaporation, cloud formation, ice melting, methane release, CO2 uptake, long term temperature changes (earth wobbles, ice ages), plate tectonics, all these things are interrelated and have a feedback effect on each other. It’s all just terribly complicated, which is why all scientists can do is model the systems with the best information they have and try to compare their models to historical data. Some basic truths remain however:

- C02 (and CH4) is a greenhouse gas, it captures some of the infrared energy that is emitted from the earth (as heat radiation) back at the earth thus causing heating that is additional to that coming in from the sun.
- the amount of C02 we have put into the atmosphere has massively increased since 1850. It has been estimated that each year we introduce into the atmosphere from fossil fuels 8 GigaTons of carbon (8000 Million Tons). The carbon dioxide levels in the atmosphere have increased from a range of approx 200-300 ppm (parts per million) in the last several hundred thousand years to a level of 387 ppm, with a considerable rise since 1800. The increase in concentration from 1850 to now has been about 35%. This is the hockey stick chart (upwards curve at the end) that is talked about.
- there are a variety of things that can be predicted to happen if temperature rises above a certain threshold:
– Ice from land that melts and goes to the sea will lead to sea rises
– the thermal expansion of water will lead to sea rise
– if tundra permafrost melts, it will release carbon dioxide and methane that has been trapped and further greenhouse gases.

The take-home message is this, Predictions of the future are difficult and bound to have error. The science of the basics of the factors and the long-term historical record is actually pretty refined and while there may be errors some of the science is solid now.

http://en.wikipedia.org/wiki/Greenhouse_gas
Vote: 0 0 You need to be logged in to vote

You must be logged in to post a comment.

Kiwiblog

Dunedin to be flooded

Share this:

Related posts:

57 Responses to “Dunedin to be flooded”

Leave a Reply