Re: Under a Green Sky

[Tommy Tyrberg <tommy.tyrberg@norrkoping.mail.telia.com>]

> > Looking at the ancient evidence, Ward notes that ice caps began to
> > shrink. "Melting all the ice caps causes a 75-meter increase in sea
> > level. [That] will remove every coastal city on our planet."
>
> Not going to happen. But if things continue, Greenland will be 
> ice-free in a few hundred years. That means "only" 7 m of sea level 
> increase. Half that, and Bangladesh is practically gone. Even just 1 
> m would make half of the country disappear in the dry season and the 
> rest during the monsoon. How will we evacuate 150 million people 
> (present estimate)?

The Greenland Icecap is not going to melt in a few hundred years. It 
takes much longer. At the end of the last glaciation 11600 years ago 
climate in northern Europa became as warm or warmer than today and 
much drier, but even so it took 2000 years for the residual 
Scandinavian icecap to melt, even though it could calve into the 
Bothnian Gulf for much of the time. The only way an icecap can melt 
fast is if it can calve out into the sea. The Greenland icecap can't 
since its bed is above sealevel. Note that not even the southern dome 
of the Greenland icecap melted during the previous (Eemian) 
interglacial when arctic temperatures were about 6 degrees centigrade 
warmer than now.

As for MIS 11 (Holstein) when the Greenland ice and at least part of 
the West Antarctic ice melted, the worrying thing about is that it 
was apparently NOT an extremely warm interglacial. Both fauna and 
flora seem to indicate lower temperatures than during the Eemian and 
in loess profiles the previous (MIS 13) interglacial has a much 
stronger weathering horizon. Where MIS 11 was unusual is that it was 
an exceptionally long interglacial, so duration may be more important 
then temperature.

Concerning Bangladesh, that country will be gone in a few centuries, 
climate warming or not. The Ganges and Brahmaputra are dammed now, 
little sediment therefore comes into the delta and the sea is going 
to erode it away pretty quickly. The same thing is happening to the 
Nile Delta since the Assuan dam was built.

Tommy Tyrberg