NZ Summer and Global Warming

Archive of NZ Weather & Climate
Forum rules
These topics are a read-only archive and may be subject to out-of-date information.

For today's weather discussion head to: New Zealand Weather & Climate
User avatar
NZstorm
Posts: 11333
Joined: Mon 10/03/2003 19:38
Location: Grey Lynn, Auckland
Has thanked: 342 times
Been thanked: 361 times

Unread post by NZstorm »

apparently Bob McDavitt was saying that we're in for the hottest summer in a decade, anyone else heard this?
Haven't heard that officially but thats my thoughts as well, based on the fact that we are due for a hot summer and the whole of the northern hemisphere have just had one of their warmest summers on record. In the case of USA, the hottest year since records began! The effects of global warming are being felt most in continental regions though. NZ is somewhat sheltered from rising temperatures by our oceanic situation.
Weathermad
Posts: 349
Joined: Tue 07/06/2005 15:46
Location: Christchurch
Has thanked: 0
Been thanked: 0

Unread post by Weathermad »

I did read about Bob McDavitts comments today about a hot summer and yet NIWA was forecasting a cooler,drier summer with a moderate El Nino event down here in Canterbury which surprised me a little as our last significant El Nino event here sent the temperatures through the roof!

I have done a little research on this so-called global warming theory and wondered if it's more global extremes than global warming

We've heard that West Antartic is warming up and that the ice shelf is reducing in size and yet East Antartic is cooling down and increasing in size

I looked at some figures from London,England(dating back to 1659-a month by month breakdown) and although they've had their warmest summer in centuries,the figures showed that they have had very warm spells and very cool spells in centuries gone by
In 1795, the average daytime temp for January was -3 degrees(usually2- 3 degrees) and yet the following January it was up to 7.3, a difference of 10 degrees!...
This has occurred on a number of occasions and enlightened me to the fact that the current phenomenon is not unheard of...It seems to be that there are a number of facts that can go either for or against the global warming argument

I wonder if it is all somewhat cyclical...Anyone else have any thoughts on the matter?
User avatar
Michael
Posts: 7210
Joined: Thu 27/03/2003 12:04
Location: Rainy Manurewa, Auckland - "City of Gales"
Has thanked: 0
Been thanked: 1 time
Contact:

Unread post by Michael »

The northern hemisphere appears to be getting warmer but its happened in the past and its colder here than in the 70s
RWood
Posts: 3745
Joined: Sat 24/01/2004 16:56
Location: Wellington
Has thanked: 188 times
Been thanked: 123 times

Unread post by RWood »

Australia's warming of late more than cancels out our sluggishness. :? ;)

I wouldn't take Bob McD's comments too seriously - an El Nino onset in spring is very unusual and there are therefore few precedents to draw on re the coming summer temperatures.
Last edited by RWood on Mon 06/11/2006 19:53, edited 1 time in total.
Achten
Posts: 141
Joined: Thu 20/03/2003 20:57
Location: Hawkes Bay
Has thanked: 0
Been thanked: 19 times
Contact:

Unread post by Achten »

You here/read arguements both ways. The way I look at it is that we cannot continue to to polute at the rate we are without it causing somekind of change. Global warming maynot be absolutely right but we will pay one way or another. It could be global cooling?
User avatar
Willoughby
Site Admin
Posts: 4433
Joined: Sat 14/06/2003 16:18
Location: Darwin, Australia: Storm city
Has thanked: 264 times
Been thanked: 288 times
Contact:

Unread post by Willoughby »

I think it all just depends how strong the sub-tropical jetstream is, and how far across the Tasman we get these warm westerlies. NW Australia has been very hot during the last month.. with a big increase in convectional rain there. NSW looks like it will become blistering with heat.. but I just dont see that happening here.. may be periods of constant cooler southwesterlies over the lower South Island, and an increase in northerly airflows over the upper North Island. (cooler water to NZ's NE should increase air pressure that way, and inturn give us more N/NW winds)

But if that westerly gets revving up after a SE Aus heatwave, we should see some record temps again under northwesterlies. BoP and Gisborne should look set to be very dry.

I think urbanisation is the major factor in this global warming trend, if you have a look at the world wide SST anomalies, the reddest spots have been quite close to developed nations like UK, western Europe, Japan, south coast of South Africa and even Sydney.

Steve Ready said last year that "we are due for a big one" (cyclone) but never prevailed.. and what about NIWA's claim calling for a cool summer.. a contradiction between the MetService and NIWA? We'll see... :)

And Stuart, yes! More humidity please!! So far our thunderstorms this spring have been blahh!! :-S
C-Nimbus
Posts: 692
Joined: Tue 20/01/2004 13:22
Location: Waitakere City - Westie!!
Has thanked: 0
Been thanked: 0

Unread post by C-Nimbus »

Foggy Hamilton wrote:
And Stuart, yes! More humidity please!! So far our thunderstorms this spring have been blahh!! :-S
well i spose the moisture has to come from somewhere!

maybe this year i might be brave and start wearing a pair of these..

Image

but then again, maybe not :oops:
RWood
Posts: 3745
Joined: Sat 24/01/2004 16:56
Location: Wellington
Has thanked: 188 times
Been thanked: 123 times

Unread post by RWood »

[quote="Foggy Hamilton
I think urbanisation is the major factor in this global warming trend, if you have a look at the world wide SST anomalies, the reddest spots have been quite close to developed nations like UK, western Europe, Japan, south coast of South Africa and even Sydney. :-S[/quote]

You seem to have overlooked Greenland, Alaska, Siberia and West Antarctica - urbanised????? :roll:

This is for 2005: http://data.giss.nasa.gov/gistemp/2005/
User avatar
Willoughby
Site Admin
Posts: 4433
Joined: Sat 14/06/2003 16:18
Location: Darwin, Australia: Storm city
Has thanked: 264 times
Been thanked: 288 times
Contact:

Unread post by Willoughby »

You seem to have overlooked Greenland, Alaska, Siberia and West Antarctica - urbanised?????
With the exception of Greenland, those areas are subject to the greatest standard deviation in anomalies than anywhere else. Satellite monitoring is what they rely on up there (not many buoys), and only take the observation at the sea surface.

The base climatology, nor the actual observation is that accurate yet.
RWood
Posts: 3745
Joined: Sat 24/01/2004 16:56
Location: Wellington
Has thanked: 188 times
Been thanked: 123 times

Unread post by RWood »

I'm glad you allowed Greenland an exception - and there's plenty of on-the-ground evidence confirming Alaskan warming. There was a recent NASA report on an alleged massive net ice loss in Greenland in the last 12 months or so. Not to mention other reports on the shrinkage of "perennial" (ie year-round) sea ice in the Arctic.

If you look at Australian reports and graphs there's no reason to think that urbanisation is a dominant factor.
tich
Posts: 3467
Joined: Sat 15/03/2003 18:32
Location: Christchurch (St Albans)/Akaroa
Has thanked: 21 times
Been thanked: 91 times

Unread post by tich »

I have done a little research on this so-called global warming theory and wondered if it's more global extremes than global warming
The global warming is of climatic averages, and an expected feature of this climate change is an increase in extremes resulting from a more volatile atmosphere. Thus events like Canterbury's June snowstorm could be made worse by this increased atmospheric instability. Also, melting of polar icecaps can disrupt ocean currents - in the case of the North Atlantic, this could possibly shutdown the Gulf Stream, thereby chilling Western Europe.
You here/read arguements both ways. The way I look at it is that we cannot continue to to polute at the rate we are without it causing somekind of change. Global warming maynot be absolutely right but we will pay one way or another. It could be global cooling?
I agree - even if human induced global warming isn't happening, our species had better change the way it treats our planet and uses its natural resources or the future won't be pretty.
Weathermad
Posts: 349
Joined: Tue 07/06/2005 15:46
Location: Christchurch
Has thanked: 0
Been thanked: 0

Unread post by Weathermad »

The issue I have with global warming is the likes of Al Gores 'An Inconvenient Truth'(with some inaccuracies) and also how many nations will use it an engineering tool for upcoming elections(Dr Sterns report containing again some misinformation)

It seems to me that we are being forcefed some information and that only certain facts are used to push the global warming argument...I just smell a rat here politically
RWood
Posts: 3745
Joined: Sat 24/01/2004 16:56
Location: Wellington
Has thanked: 188 times
Been thanked: 123 times

Unread post by RWood »

The mainstream media in the US in particular (plus most Republican politicians) push a conservative agenda, and have no interest in "sustainable" solutions, particularly as the religious sector of their support think it is the "end of days" anyway, so future life on earth is not important.

Their propaganda against global warming notions far outweighs what you're talking about. But as this is a weather forum, it is a natural home for contrarians. :roll: If you're influenced by a couple of individuals who have been reported on recently in this country, I could relay comments I've heard from NZ scientists - but not publicly.
Weathermad
Posts: 349
Joined: Tue 07/06/2005 15:46
Location: Christchurch
Has thanked: 0
Been thanked: 0

Unread post by Weathermad »

I take your point

A lot of what Ive come across in regards to this has been on our talk station

We've interviewed a number of scientists for and against the theory,had a number of talkback callers and getting their thoughts or reaction...Some of it is emotive, no doubt about it!

A number of farmers say that they have lived on the land for generations and have kept records of their own and in a number of cases,the global warming idea goes against their statistics

It is a huge area and I still suspect a rat...When the information is thrown at us in a way that is what I call inappropriate and in some cases inaccurate, that's when I start to become suspicious...I believe more and more people are seeing through this and making up their own minds

I believe it's good to have a more balanced debate about it all in a public arena
Manukau heads obs
Posts: 12305
Joined: Mon 10/03/2003 16:30
Location: West Coast Road, Manukau Peninsula, North Island
Has thanked: 0
Been thanked: 0
Contact:

Unread post by Manukau heads obs »

the climate/earths temperature , is not stable
it has changed significantly over the last 5000 years
they used to grow grapes easily in the UK, now only in the far south
etc

so,the climate has warmed/cooled anyway at times in the recent past, so its going to change again, no doubt about it....
but how fast, and if the pollution we are putting into the atmosphere will make the next change bigger and occur sooner, is the debate i guess
Image
Brian Hamilton, weather enthusiast. My weather dataEmail: [email protected]
User avatar
NZstorm
Posts: 11333
Joined: Mon 10/03/2003 19:38
Location: Grey Lynn, Auckland
Has thanked: 342 times
Been thanked: 361 times

Unread post by NZstorm »

Yes, theres a lot of speculation about global warming being put forward as fact. I'm keeping an open mind on the issue.
User avatar
TonyT
Moderator
Posts: 2878
Joined: Thu 08/05/2003 11:09
Location: Amberley, North Canterbury
Has thanked: 352 times
Been thanked: 1146 times

Unread post by TonyT »

Its a classic example of the murky interface between politics and science, and if some of the science proves to be correct, then it is probably the most important example of the murky interface (ie gray area) around at present.

Politicians are ruthless at picking up whatever bits and pieces of science they want to support their stance. We shouldn't criticise them for this, its what they do, but lets make sure we recognise it for what it is. By picking bits and pieces and talking about them emotionally, instead of dispassionately considering all the science, politicians are bound to be considered with some scepticism.

However, some scientists believe that they have a moral obligation to society to highlight key issues and in turn have chosen to speak emotionally about them. While that is their right, it further undermines the perceived solidity of the science they practice.

My own feelings, for what they are worth, is that we can and should place considerable weight on the science which is based strongly on observation - ie it does seem likely that we are in a period of rapid temperature increase, sure some of that is driven by urbanisation, but some isnt. We know from observation that the earth's climate has varied a lot in the past, and that natural variation is considerable and ever present. We also know that the current level of warming is at the outer bounds of that natural variation (if not exceeding it). We also know that CO2 has been a fully functioning greenhouse gas for billions of years, and that in recent years CO2 concentrations have risen markedly. These things I think we should take very seriously.

I think we can place some weight on the theories which have been developed - the idea that the increase in CO2 emissions is due largely to industrialisation, that industrialisation is increasing apace in third world countries, and that it seems likely that increase will continue into the future. This in turn suggests that an increased greenhouse effect is likely, and may accelerate. We also have considerable theories which suggest that the earth's climate system is highly complex, non-linear, and subject to varying feedbacks, many of which are poorly understood. These are all things I think we should take seriously and consider well.

I think we have to question just how much weight we place on the computer modelling which has driven much of the "hard data" generated so far. I suspect that the earth's climate system is several orders of magnitude more complex than the current models portray, and I am not convinced that the data used for near-future climate projections is as robust as it could be. These are things I think we should think about, and have an open mind on.

I think that many of the conclusions about what the climate will be like, at a local level, in the next 100 years are very suspect. For example, the suggestion that agricultural zones will migrate southwards in New Zealand, based on changes in mean temperature. My argument is that agriculture is governed largely by extremes, not means. Even if the mean temperature rises by 3-5degC in 100 years, Canterbury will still be the same distance from the Antarctic as it is now, and still at the risk of occasional severe snow storms and heavy frosts such as we had this winter. These will limit the type of agriculture that is possible here, regardless of the mean temperature. There is also the possibility that extreme events (like the snow storm) will become more extreme or more common.

Another example, everyone assumes that an increase in westerly airflow (as postulated by the models) will result in an increase in mean temperatures for Canterbury, but in the spring and autumn days with westerly flow are more likely to have clear skies and bring frosts. Plus, light to moderate westerly flows lead to northeast winds on the Canterbury Plains, which are often a cooling wind. So, I have very little confidence in our ability to plan for the future based on the data we currently have. These things, I think, should be viewed very critically indeed.

It seems to me that it is helpful to allow for a range of "belief" depending on what part of the climate change science you are looking at. I dont feel it is helpful to lump it all together and say yea or nay to the whole lot.
RWood
Posts: 3745
Joined: Sat 24/01/2004 16:56
Location: Wellington
Has thanked: 188 times
Been thanked: 123 times

Unread post by RWood »

TonyT wrote:
My own feelings, for what they are worth, is that we can and should place considerable weight on the science which is based strongly on observation - ie it does seem likely that we are in a period of rapid temperature increase, sure some of that is driven by urbanisation, but some isnt. We know from observation that the earth's climate has varied a lot in the past, and that natural variation is considerable and ever present. We also know that the current level of warming is at the outer bounds of that natural variation (if not exceeding it). We also know that CO2 has been a fully functioning greenhouse gas for billions of years, and that in recent years CO2 concentrations have risen markedly. These things I think we should take very seriously.

I think we can place some weight on the theories which have been developed - the idea that the increase in CO2 emissions is due largely to industrialisation, that industrialisation is increasing apace in third world countries, and that it seems likely that increase will continue into the future. This in turn suggests that an increased greenhouse effect is likely, and may accelerate.
My problem is the number of individuals (aside from self-interested politicians, lobbyists and other groups who have no concern for the long-term effects of any phenomenon at all, let alone climate variability) who totally reject even the core statements above that I've extracted from your quote. Such people are certainly to be found on weather forums and in newspaper correspondence, though I suspect their numbers are on the decline in Australia at present, even if for the wrong reasons.

Even if one has reservations about quite a bit of what is claimed by GW proponents, the following quoted from a contributor on a UK forum should be considered: [yes, some of it repeats what is said above]

Personally I'm getting sick of the whole discussion.

Media hyperbole.

Political machinations/incompetence.

Ignorance & greed.

"Skeptics" that pick and choose their data.

The general failure of science to communicate to non-scientists.

And the failure of the markets and industry to recognise this as one of the greatest investment opportunities ever. (cleaning up older energy infrastructures plus the opportunity to build developing countries with cleaner, greener, cheaper technology).

As was said the other night on BBC's Question Time this is (should be) a win win situation. If the science is wrong then we would have moved to a cleaner more stable(geoplolitical and price wise) energy source, but if the science is right then we would have protected the world.

The joke is with peak-oil not far-away we're going to have to make these changes anyway so why the idiotic fuss?


To this I would add: there will always be those who like to simply take positions contrary to whatever is popular/gaining currency, taking a "philosophical" approach of convenience - "there's no proof".
Weathermad
Posts: 349
Joined: Tue 07/06/2005 15:46
Location: Christchurch
Has thanked: 0
Been thanked: 0

Unread post by Weathermad »

I believe the issue is fraught with all sorts of complications that are all intertwined

It needs to be broken down segment by segment as there is a lot of confusion about it all

and finally there seems to be varying definitons of what global warming exactly is,what the consequences are and what it means for us in our own backyard...How it will affect you and me
Manukau heads obs
Posts: 12305
Joined: Mon 10/03/2003 16:30
Location: West Coast Road, Manukau Peninsula, North Island
Has thanked: 0
Been thanked: 0
Contact:

Unread post by Manukau heads obs »

tony t, there is some sectors of horticulture that will be affected by only small changes in tempertures.....i.e chill times, to cause blosoming, to name just one example...i.e some areas that are marginal now for cetain horticultural crops, if only 0.5oC rise in temperature, will not be viable any more

but then there are other positive things with warmer winter temperatures.....more grass growth over winter for one example.....but then warmer summers will mean tropical grasses will be become more dominant and agressive in the northern half of the NI and spread further south (kikuyu for example the optimum temperature is 30oC )
Image
Brian Hamilton, weather enthusiast. My weather dataEmail: [email protected]
Cameo1
Posts: 417
Joined: Mon 24/04/2006 19:32
Location: New Lynn West, Auckland
Has thanked: 0
Been thanked: 0

Unread post by Cameo1 »

The global warming argument is full of problems. The main one being that we do not have enough scope of what is natural climate variability and what isn't. There are theories that support the idea that sea level will in fact drop. With higher temperatures evaporation from the sea will be at a much higher rate, because of this, the ice caps may grow in size as is supposedly occurring in parts of Antarctica due to more snow falling. Also an important point to note is the fact that CO2 is in fact NOT the most important green house gas. Water vapour is. There are also some scientists that believe that regardless of the levels of CO2 in the atmosphere plants will adapt to it, so the more there is, the more they will use, which is certainly the case for where I am living at the moment where I have observed an exponential increase in height and new plant growth over the last 2 years.
Sun spot cycles may also play an important role, as there appearance correlate to 'The Little Ice Ages' of the past millennium. Some say we are about to head into a cooling phase with the arrival of several sun spots.
Here is an interesting site http://solar-center.stanford.edu/sun-on ... arsun.html
Manukau heads obs
Posts: 12305
Joined: Mon 10/03/2003 16:30
Location: West Coast Road, Manukau Peninsula, North Island
Has thanked: 0
Been thanked: 0
Contact:

Unread post by Manukau heads obs »

i cant see,myself, increased evaporation causes a sea level drop...the oceans just have too much total water volume, for that volume to be influenced by evaporation...that would be like taking a drop out of a bucket and then trying to measure the drop in volume, to my thinking

yup, increased CO2 has been shown, in the lab, to increase plant growth.....when the dinosaurs were around, there was a lot of plant growth on the planet...had to be, to support such large appetites!
Image
Brian Hamilton, weather enthusiast. My weather dataEmail: [email protected]
Cameo1
Posts: 417
Joined: Mon 24/04/2006 19:32
Location: New Lynn West, Auckland
Has thanked: 0
Been thanked: 0

Unread post by Cameo1 »

Manukau heads observer wrote:i cant see,myself, increased evaporation causes a sea level drop...the oceans just have too much total water volume, for that volume to be influenced by evaporation...that would be like taking a drop out of a bucket and then trying to measure the drop in volume, to my thinking

yup, increased CO2 has been shown, in the lab, to increase plant growth.....when the dinosaurs were around, there was a lot of plant growth on the planet...had to be, to support such large appetites!
Again, it's just a theory, so no proof yet for that evaporation theory. It just gives us other options instead of that 'we're all doomed' attitude. Who knows maybe our pollution is slowing down a cooling period? :o
What ever the case, we are totally ignorant in this one.
Manukau heads obs
Posts: 12305
Joined: Mon 10/03/2003 16:30
Location: West Coast Road, Manukau Peninsula, North Island
Has thanked: 0
Been thanked: 0
Contact:

Unread post by Manukau heads obs »

i guess there must be way to know the total volume of the oceans...
and also to estimate the amount of evaporation now, and then how much if the atmosphere warms up...
but, more evaporation would mean more rain...so the water gets returned anyway,..

but i am no expert
Image
Brian Hamilton, weather enthusiast. My weather dataEmail: [email protected]
RWood
Posts: 3745
Joined: Sat 24/01/2004 16:56
Location: Wellington
Has thanked: 188 times
Been thanked: 123 times

Unread post by RWood »

Cameo1 wrote:
Manukau heads observer wrote:i cant see,myself, increased evaporation causes a sea level drop...the oceans just have too much total water volume, for that volume to be influenced by evaporation...that would be like taking a drop out of a bucket and then trying to measure the drop in volume, to my thinking

yup, increased CO2 has been shown, in the lab, to increase plant growth.....when the dinosaurs were around, there was a lot of plant growth on the planet...had to be, to support such large appetites!
Again, it's just a theory, so no proof yet for that evaporation theory. It just gives us other options instead of that 'we're all doomed' attitude. Who knows maybe our pollution is slowing down a cooling period? :o
What ever the case, we are totally ignorant in this one.
If this story's notions turn out to have any validity, it will not only contradict what you're saying about pollution, but also indicate that greenhouse effects have been underestimated.

http://news.bbc.co.uk/2/hi/science/nature/4171591.stm
Locked