Sunday, September 18, 2005

Latent heat of ice and climate models

This looks like an excellent example how the self-confident climate "big shots" are ignorant about basic numbers in physics and how worthless their reasoning is.

Steve Connor wrote another dramatic article in The Independent claiming that global warming is past the point of no return. Such articles appear virtually every day. They're addressed to the people who know even less than the journalist himself. But the fate of our civilization - always an uncertain thing - is not what I want to mention here.

William Connolley is one of the main driving forces among the 9 people who started the alarmist climatologist propagandistic blog called RealClimate. William is one of the main people who define the "scientific consensus" about the climate. If you believe the "scientists" without calculating it yourself, you believe people like William Connolley.

William also has his own private blog called Stoat. In the newest article, he questioned the statement by Steve Connor that the Arctic sea ice is a major heat sink. In the main text he said that ice couldn't be a heat sink because it reflects solar radiation. So I explained him that when we say that it is a heat sink, we mean that it absorbs the heat particularly from the ocean, not from the Sun. I expected him to realize his error.

Instead, he continued and wrote that the latent heat of ice is completely negligible, and they can forget about it when they work with their climate models. In order for you to see how incredible his statement is, let me say a couple of numbers.

The heat capacity of liquid water is 4,200 Joules per kilogram and kelvin. The latent heat of ice is 355,000 Joules per kilogram. What does the ratio tell you? If you melt ice, you can cool down the same amount (mass) of water by roughly 85 degrees.




Now, there are about 2 meters of ice in average in the Arctic and approximately 2 kilometers of water underneath. Simple counting shows that by melting the ice, you can cool down the whole underlying ocean by 0.1 degrees - the predicted "global warming" trend for a whole decade. (Let's not talk about what's actually happening and what will be happening because this is too politically sensitive a topic.)

Also, the atmosphere is equivalent to roughly 10 kilometers of air. Its mass is like 10 meter high column of water. But because the specific heat capacity of air is just 1/4 of that of water (counted per kilogram), the atmosphere is something like 3 meters of water. That means that 2 meters of ice have enough latent heat to cool down the whole atmosphere above the Arctic by 50 degrees; these are order-of-magnitude estimates meant to evaluate whether an effect is negligible. Alternatively, you may also consider atmospheric CO2 only which is 380 parts per million. The latent heat of the sea ice would be enough to cool down the CO2 in the atmosphere by something like 150,000 degrees if it were possible.

Nevertheless, the latent heat of sea ice seems negligible to William Connolley and probably also most of his colleagues; they prefer the atmospheric CO2 as the object that everyone should look at (especially the 2 parts per million that the humans produce every year). They neglect things such as ice in their considerations. They omit such entities in their models, too. Water is also the most important greenhouse gas (more than 90% of the total effect) but they neglect it as a greenhouse gas, too. They don't care whether one increases or decreases the total amount of clouds and water droplets in the atmosphere. They don't care that the specific heat capacity of water is the highest one after Hydrogen and Helium. Water does not matter for them. What's the real reason that water is not interesting? Well, it's because the evil capitalists produce as much water as the nice communists and ecoterrorists.

They just pick one term - one insight from high school physics - among hundreds of others that they neglect. They apply it to one, politically most interesting gas, and calculate something from this one term and call it science. They want others to believe that they can predict temperature for the next 100 years. The fact that they neglect sea ice that cools down their gas component by 150,000 degrees if it melts does not matter to them. It's negligible, is not it?

Many journalists then transform these "scientific insights" into even more impressive articles, and various politicians use these "improved" insights to fight against the whole civilization. But the scientific basis of these claims is based on totally weird assumptions such as that the latent heat is negligible.

In reality, ice matters. Some glaciers grow; some of them retreat - and the current ratio is not necessarily 50:50 because the laws of political correctness do not apply to mother Nature. The Antarctic ice is growing (this is an argument by NASA that the global warming is not global and it is not exactly warming either), the Arctic ice is diminishing. It's pretty clear that the places with a lot of ice will have more stable temperatures (typically close to 0 degres Celsius) because ice can regulate the fluctuations. The heat capacity including the latent heat is simply large. These are rudimentary insights from elementary school physics and they have absolutely no political flavor if they are understood rationally.