G'day Paul,
I liked your comments about ships. You are right about just how inaccurate the figures are because of the various variables to the way the temperatures were recorded. There are many more but you made a good point and one that is often overlooked when figures for sea temperatures are used for the 20th century or air temperature above ships in the same period.
I have a problem with your proposition concerning methane deposits and this causing the end of the last ice age. I know the terminology gets messed up all the time but this Ice Age has been around considerably more than 1 million years. The glacial period that ended a little more than 11,000 years ago is probably what you are referring to.
Your methane theory is something I have not come across as the cause of the end of the last glacial period but a few of your comments can be directly addressed. There was not large loss of human life at the glacial/interglacial period boundary. Quite the reverse in fact. The populations of the world expanded around that time. There is a great deal of evidence as to populations of man from the transition from hunter/gatherer to agrarian societies and a vast amount of studies relating to populations around the times you mentioned.
There were pretty much no cities 11,000 years ago. The largest settlements were really quite small indeed.
While I am not an expert in methane deposits I had the luck to read about the methane that is available as perhaps an alternative energy source around the US only a week or so ago. This is not on the ocean floor. Because of salinity, the bottom of the oceans are not frozen wastelands at all. The methane is in sediment deposits and these have been around for geological periods (ie an awful long time more than one or two inter-glacial periods). They are not all that easy to extract because in order to exist at all they need a combination of factors that thus far have not been found other than beneath the ocean floors. From the science that was discussed in how they were formed and how they could be extracted it would appear that not even switches to or from full blown Ice Ages would dislodge the deposits. I understand there is a theory, based on reasonable evidence, that major methane release did occur and it is possible this was at the same time as climate change. This is around 55 million years ago. Just why it happened then, I have no idea, but that is the only reference to methane deposits being released I could find.
As to attempts at cooling the planet, do you really want to live in a glacial period? Only about 2% of the population would survive. Painting a few roofs white is not going to change a thing by the way as the grime that would build up on the roofs would drop their albedo (solar radiation reflectively) substantially fairly quickly and the percantage surfaces would be tiny in the scheme of things. But let's say you came up with a way to actually cool the planet. Do you really believe you are God? That you could work out a way to cool the planet by just the right amount without affecting the myriad of interconnected systems?
This is a science forum. Perhaps you could point out any reference to massive methane release 11,000 odd years ago. Methane would leave traces and would be well known. Surely you would have no difficulty in finding major references to it.
Richard
