The National Forum   Donate   Your Account   On Line Opinion   Forum   Blogs   Polling   About   
The Forum - On Line Opinion's article discussion area



Syndicate
RSS/XML


RSS 2.0

Main Articles General

Sign In      Register

The Forum > Article Comments > Under the gun > Comments

Under the gun : Comments

By Julian Cribb, published 9/6/2009

While we continue to dawdle on greenhouse mitigation policy we seem blithely unaware there is a gun pointed at our heads. The clathrate gun.

  1. Pages:
  2. 1
  3. Page 2
  4. 3
  5. 4
  6. 5
  7. All
skeptics should have a look at the Vostock ice core data. See:
http://maps.grida.no/go/graphic/temperature-and-co2-concentration-in-the-atmosphere-over-the-past-400-000-years
This data plots temerature and CO2 concentration for the last 400,000 yrs. The key points are that:
1. Temperature and CO2 have roughly risen and fallen in line with each other over this period.
2. The dominant cycle is the 100,000 yr cycle driven by orbit eccentricity.
3. The noticeable point is that the earth slowly cools for approx 85% of the cycle while heating takes place in the remaining 15%! The implication here is that once heating start positive feedback clicks in and increasing temp leads to increasing CO2 which leads to increasing temp etc.
4. Some of the short term variation is caused by shorter orbit, precession etc. driven cycles. Others may have been driven by spurts in greenhouse emissions where large forests, peat bogs and methane deposits dried out or reached some critical temperature.
5. Changes winds and currents may be responsible for some of the other spikes. The 12 deg C spike about 14,000 yrs ago was thought to have been due to changes in wind pattern that resulted when the tropics became more humid. (Google Greenland Ice Cores.)
What worries me is that we don't really know how much extra greenhouse gases will be released as temperature rises. If temperatures rise higher than they have been for a long time we may trigger a run of greenhouse gas release from something that has been acumulating for a long time. We know that methane is trapped in permafrost and shallow clatherates but we don't know how much or what the trigger temeratures are.
My risk assesment says get on with the easy, low cost emissions reduction. For example, electricty accounts for approx. 50% of our emissions and our total per capita is only 10,000kWh/yr including power for exports. Adding 10 cents per kWh adds $1000 per capita - small cheese insurance money.
Posted by John D, Tuesday, 9 June 2009 1:50:17 PM
Find out more about this user Recommend this comment for deletion Return to top of page Return to Forum Main Page Copy comment URL to clipboard
What bugs me most is how the Libs bag Labor for even thinking environmentally and the Greens bag them for not thinking anywhere near enough
Posted by Matthew T, Tuesday, 9 June 2009 2:45:53 PM
Find out more about this user Recommend this comment for deletion Return to top of page Return to Forum Main Page Copy comment URL to clipboard
Why is transferring to clean, sustainable, recyclable methods such a threat to so-called 'sceptics'?

What justification is there to continue to pollute and use all our non-renewable resources?

You don't have to accept AGW to realise that to continue as we are, has no foundation in rational thought. Our planet is not a magic pudding, how often do we have circle around in this debate?

Rather than blither on about how AGW is just a scare campaign, offer some solid reasons for continuing as we have been with manufacturing, agriculture, population increase, destruction of forests, over fishing?

Where is the argument FOR Business-As-Usual?

http://www.youtube.com/watch?v=vFGU6qvkmTI&feature=email

There is overwhelming argument against BAU.
Posted by Fractelle, Tuesday, 9 June 2009 3:56:53 PM
Find out more about this user Recommend this comment for deletion Return to top of page Return to Forum Main Page Copy comment URL to clipboard
Clathrates are maintained in their frozen state by a combination of low temperature and high pressure. They are stable at up to zero degrees C at atmospheric pressures but at up to 18 degrees C under the high pressures that prevail under the oceans. The temperature of the oceans below the thermocline is in the range minus 2 to plus 4 degrees. The much reduced mixing of water across the thermocline means that no matter what the increase in sea surface temperature it is inconceivable that 10 or more degrees of this could be transferred to ocean depths. And ocean heat, based on the most recent research from the Argo float program, is decreasing, at least since 2003.

Leakage of methane from natural gas deposits occurs on land and under the sea, and is the origin of at least some clathrate deposits. An event such as a submarine volcanic eruption could conceivably cause a localised sudden release of clathrates but it is also inconceivable that we can do anything to cause it or stop it. So we don’t need to worry about it; to suggest otherwise is just another piece of alarmist nonsense.
Posted by malrob, Tuesday, 9 June 2009 4:02:16 PM
Find out more about this user Recommend this comment for deletion Return to top of page Return to Forum Main Page Copy comment URL to clipboard
Sounds like another "boogey" word

from the hysterical and hyperactive minds of those who are predisposed to believe in "things to support the notion of man-made climate change" ....

and other fairy tales.

The "Brothers Grimm" being replaced by the boringly grimmer.
Posted by Col Rouge, Tuesday, 9 June 2009 4:09:22 PM
Find out more about this user Recommend this comment for deletion Return to top of page Return to Forum Main Page Copy comment URL to clipboard
What are those people (who live long enough) going to think when they find out that no difference will have been made whether we now 'dawdle' on climate change, doing nothing, or spend a hell of a lot of our money on trying to do something because it is better than doing nothing?

Let down is probably putting it mildly.
Posted by Leigh, Tuesday, 9 June 2009 4:30:45 PM
Find out more about this user Recommend this comment for deletion Return to top of page Return to Forum Main Page Copy comment URL to clipboard
  1. Pages:
  2. 1
  3. Page 2
  4. 3
  5. 4
  6. 5
  7. All

About Us :: Search :: Discuss :: Feedback :: Legals :: Privacy