Dredd Blog: Weekend Rebel Science Excursion

Friday, July 4, 2014

Weekend Rebel Science Excursion - 33

Ah, Friday.

So, let's do some science.

Today, I want to show an example of dementia in the news media, a dementia of the criminal insanity sort.

Yahoo News has this headline "Gov’t Scientists: Antarctic Sea Ice Is Growing — Because Of Global Warming" and Media Matters has this headline: "CNBC Caught Soliciting Writer To Claim Global Warming Is A Hoax."

More about those in a moment, but first let's do some Fifth Grade science that Yahoo News and CNBC must have failed ... assuming they took any science.

The Yahoo News piece got its story then quoted from a source that indicated:

Government scientists are not only blaming global warming for the centuries-long collapse of western Antarctic ice sheets, but global warming is also being blamed for record levels of sea ice in the South Pole.

Antarctica’s sea ice set another record this week, reaching 815,448 square miles above normal, breaking a record set this past weekend of 800,776 square miles above normal ice coverage.

These two records set within a week of one another shattered the previous ice extent record of 710,428 square miles above average that was set back on December 20, 2007.

(Gov’t Scientists: Antarctic Sea Ice Is Growing, emphasis added). That site is one of several denier sites that are subjects of the study of Agnotology (Agnotology: The Surge - 5).

What government scientists actually say is that the volume, i.e. the quantity of ice in Antarctica has been decreasing for years because of global warming:

There has been lots of talk lately about Antarctica and whether or not the continent's giant ice sheet is melting. One new paper, which states there’s less surface melting recently than in past years, has been cited as "proof" that there’s no global warming. Other evidence that the amount of sea ice around Antarctica seems to be increasing slightly is being used in the same way. But both of these data points are misleading. Gravity data collected from space using NASA's Grace satellite show that Antarctica has been losing more than a hundred cubic kilometers (24 cubic miles) of ice each year since 2002. The latest data reveal that Antarctica is losing ice at an accelerating rate, too.

(NASA, Is Antarctica Melting?, cf. Antarctic Ice Melt, emphasis added). The news sources who do not know the difference between ice extent (square miles) on the surface of the ocean, and ice volume (cubic miles) are a problem.

The poles are losing their volume of ice on land (cubic quantity) even if ice extent (square quantity) increases or decreases from time to time on the ocean surface:

What is the difference between ice "extent" compared with ice "volume"?

One has to do with how much surface area an ice sheet covers, the other has to do with how much ice volume there is in that ice sheet.

Be sure to notice and remember that when you read opinions about whether or not the amount of ice at the Earth's poles is decreasing or increasing, because one of those words used to describe it means "area", but the other means "volume."

The difference between the two concepts could not be greater when one is attempting to determine whether the amount of ice at the Earth's poles is increasing or decreasing.

In other words, if you wanted to know how much water would end up in the oceans if the polar ice melts, would you use formulas to calculate "area" or would you use formulas to calculate "volume" of the ice sheet?

With "extent", i.e. "area", the result of that formula is expressed in square miles, but the result of the volume formula is expressed in cubic miles.

A 2 inch ice cube in the 2 inch deep ice tray of your refrigerator is illustrative; if you want to calculate the extent or area of that ice cube (length x width) it is 2 inches x 2 inches, which equals the "extent" or "area" of 4 square inches.

But you can't figure out how much water there will be if the ice melts until you know if the ice goes to the top of the tray, or is only half way to the top; half full (the length and width are both still 2 inches in either case).

We can illustrate this by calculating the full volume (length x width x height) expressed as 2 inches x 2 inches x 2 inches which is a volume of 8 cubic inches; and we can illustrate this further by calculating half full, 2 inches x 2 inches x 1 inch, which is a volume of only 4 cubic inches.

With polar ice calculations we use the same formulas, except that the resulting numbers are expressed in miles not in inches.

Like the ice cube tray, the same ice sheet in terms of number of square miles when the ice is as thin as a piece of paper, compared to that number of square miles of ice sheet when it is a mile thick, would be radically different in terms of cubic miles, in terms of ice volume.