Past temperatures and CO2 levels correlations

[Manukau heads obs]

HI
stumbled across this interesting graph, based on ice core data
http://www.niwa.co.nz/__data/assets/ima ... imate1.gif
from the Niwa web page
http://www.niwa.co.nz/ncc/clivar/pastclimate
shows that CO2 levels and temperature have a close relationship

so as CO2 levels keep on rising as they have been lately, its not hard to come to the conlusion that temperatures wil keep rising as well

also check out the difference in temperature, i.e 6oC coler during the last ice age period
and yet global warming is only talking about half that change (in getting warmer), and yet people still dont think that is possible...and yet that is exactly what happened last time CO2 levels were as high (and were higher than now), far right side of the graph)
all global warming sceptics should be shown this graph me thinks

also the article shows that sea levels are slowly increasing in NZ
:

New Zealand has four tide gauges with records for 75 years or longer (Auckland, Wellington, Lyttelton and Dunedin). Hannah (1990) used these data to calculate a rising trend in sea level of 1.3, 1.7, 2.3 and 1.4 mm per year respectively, giving New Zealand a mean of 1.7 mm per year. An update by Hannah (2004) confirmed that sea levels around New Zealand have been rising at an average rate of 1.6mm/year over the last 100 years.

Note also that the El Niño Southern Oscillation (ENSO) is a significant source of seasonal and year-to-year variability in sea level. For example at Moturiki (Mt Maunganui), the seasonal and interannual variability account for about 30% and 25% respectively of the variation in non-tidal sea level (Bell and Goring, 1998). On the same NE coast during El Niño events, seasonal sea levels can be depressed by up to 10 cm (accompanied by a fall in shelf sea surface temperatures) while during La Niña phases, sea levels can be elevated by up to 8 cm (Bell and Goring, 1997).

also long term temperature is trending up....with up and down (to be expected) variations (we are in a down in that trend at the moment, the coming years should see the warming accelerate again (some people have latched on to the current slowing as saying , see, its not happening at all, but are missing the bigger picture):
http://www.niwa.co.nz/__data/assets/ima ... 007_v3.jpg

[TonyT]

HI
stumbled across this interesting graph, based on ice core data
http://www.niwa.co.nz/__data/assets/ima ... imate1.gif
from the Niwa web page
http://www.niwa.co.nz/ncc/clivar/pastclimate
shows that CO2 levels and temperature have a close relationship

so as CO2 levels keep on rising as they have been lately, its not hard to come to the conlusion that temperatures wil keep rising as well

Actually you cant conclude that at all, based on that graph. Modern changes in CO2 levels are due to industrialisation and may (or may not) drive temperature changes now and in the near future. However, the graph relates to pre-industrial times, so something else must have been causing the changes in C02, and one possible cause is changes in temperature. If other mechanisms were causing temperature change in the historical record then its not hard to imagine C02 changes being a consequence of temperature changes due to variations in ice and vegetation cover on the earth. The graph shows a relationship, but it doesnt tell you anything about cause and effect.

also long term temperature is trending up....with up and down (to be expected) variations (we are in a down in that trend at the moment, the coming years should see the warming accelerate again (some people have latched on to the current slowing as saying , see, its not happening at all, but are missing the bigger picture):
http://www.niwa.co.nz/__data/assets/ima ... 007_v3.jpg

Well it all depends on what you call "long term" doesnt it? You are calling long term a 150 year period. If you were to look at 1500 years or 15,000 years then you would get a different picture. We dont know how significant the temperature levelling/cooling since 1999 is in the long term, but we do know that that it represents a change from the situation in the 1980s and 1990s.

[jamie]

Touchy subject... studying geography, geology and environmental science i have found that one paper tells you one thing then another throws all that away by saying another thing.

Tony has done a very good explanation on some points there that i have learnt.
Also to minipulate graphs is VERY easy. Changing a few scales here and there to MAKE things correlate is very common.

I sit on the fence in subjects like this and let other people argue about the facts

[Michael]

Probably not a touchy subject once each and everyone starts paying for it.

[NZstorm]

and yet people still dont think that is possible...and yet that is exactly what happened last time CO2 levels were as high (and were higher than now), far right side of the graph)
all global warming sceptics should be shown this graph me thinks

But how many years ago was that. The chart says 140,000 years ago! I think one problem is we are dealing with a whole lot of theory.

[Manukau heads obs]

yes, but the whole thing is that the earth has been through warmer periods (and colder ) periods before....and will again....so why not that what we have pumped into the atmosphere tip the scale one way more than it would otherwise be doing?
(but then you have the problem of cycles on top of cycles, some which might reenforce or some that might then dampen down, etc)

anyway, I think its an interesting debate and I certainly are keeping my eyes /ideas open!