Saturday, 13 December 2008

the ice retreat continues

Climate change continues to present a challenge. The argument over its reality continues, but the converts continue to outnumber the sceptics. And the world economic situation gives the realists one more reason for caution.

But the alarming data continues to mount. Among the latest news is the retreat of the Arctic ice, with the mimimum summer area in 2007 the lowest ever recorded (see graph). While some say that we've been there before, researchers say this is not just a cyclic fluctuation. Rather, the loss of ice reduces the reflection of solar heat, increasing the heat retained, and hastening the rise in local sea temperatures, thus creating a vicious circle. The future may well be worse than the graph suggests.

Data taken from BBC report

Scientists are predicting that the arctic may be ice-free in summer in less than a decade, which will have enormous environmental consequences and will threaten many arctic species. As you'd expect, there are business interests that oppose doing very much about the problem; in fact some fear that human interference in the area can only increase as the ice reduces.


  1. The more I read the more confused I become. Who to believe? I was reading this article about the global warming "hysteria". (,2933,468084,00.html)Even though it happens to be from one of my least favorite sources of news, it made some good points. In my opinion the best one was bringing up the Archimedes Principle which he explains with a simple science experiment of ice in a cup of water. When the ice melts, the water level does not rise. I had not thought of that! All this considered, I still do not believe human presence and technology could possibly have had NO effect on our planet. And we can not go on the way we have with no regard for its future.

  2. Portia, it's nice to hear from you again. While I think it is true that melting floating ice will not raise the water level, there are two factors not considered which have the effect of raising water levels.

    1. Water, like most substances, expands when heated. As the oceans heat up, even without any ice melting, the water expands in volume, and the only way it can expand is by the surface levels rising. And because the oceans are so large and deep, that expansion is significant.

    2. Not all the ice that is melting is floating. Concerns are being expressed about massive "ice sheets" in Greenland, and about retreating glaciers in various places. This melting ice adds water to the oceans (when the water eventually reaches the sea) and thus obviously raises the water level.

    So, as seems often to be the case, global warming sceptics may build their case on limited information. When the whole picture is considered, and the data incorporated into the best scientific models, it is the view of most scientists that the predicted problems are almost certain, only the exact degree of change in uncertain.


Note: only a member of this blog may post a comment.