It Would Be Nice to Know More about Ice
In early May, newspapers across the country reported that a team of "adventurers" from Minnesota was setting off to "document climate change" at the North Pole.
According to newspaper reports, they aim to "draw [attention to] the gradual warming of Earth's climate" and "hope to convince skeptics, especially in the Bush administration, that global warming is real ..."
In other words, this summer will bring a barrage of misinformation about the Earth's ice structures provided by non-scientists who make casual observations and then claim they know what caused the situations they are observing.
Scientists, of course, do not operate this way. They don't start their work with a political axe to grind, with the aim of "drawing attention" to something. They don't make a few observations and then jump to conclusions about causation. And they don't ignore the work of scientists who have gone before them.
Scientists, these Minnesota two are not. And yet we'll no doubt hear more about their "research" than we have about the work that really matters--the science.
A few years ago, Dr. R.J. Braithwaite's peer-reviewed article in Progress in Physical Geography described a "mass balance analysis" he conducted of 246 glaciers sampled all around the world between 1946 and 1995. That's 50 years of data.
Braithwaite found some glaciers were melting, while a nearly equal number were growing in size, and still others remained stable. He concluded, "there is no obvious common or global trend of increasing glacier melt in recent years."
But if your goal is to frighten the public into thinking humans are causing global warming with potentially catastrophic consequences, there is no shortage of melting glaciers to report upon. By some estimates, 160,000 glaciers exist on Earth. Only 63,000 have been inventoried, and only a few hundred have been studied in the detail described by Braithwaite.
For example, a favorite melting glacier of the global warming activists sits atop Mt. Kilimanjaro in northern Tanzania, near the equator. Satellites have been measuring temperatures near its summit for more than 25 years, finding no warming at all, yet the global warmers trot out Kilimanjaro as a poster child for their cause.
A scientific study published in Nature in November 2003 explained that deforestation of the mountain slopes--not warming temperatures--explains the melting. But the scaremongers don't particularly care why Kilimanjaro is melting, only that it is. Any other facts get in the way of their lobbying and fundraising efforts.
The scaremongers also point out that as many as seven ice shelves have broken off the Antarctic continent over the past 50 years. They blame global warming, rather than address the inconvenient confounding evidence--that the continent is actually cooling dramatically. Between 1986 and 2002, the continent cooled by .7 degrees C per decade. There also has been a statistically significant increase in sea ice area, as well as an increase in the length of the sea ice season, since 1990.
Sea ice plays a key role in regulating the surface exchange of heat, moisture, and salt between the atmosphere and the oceans. It is a high-latitude phenomenon and can be found only in the Arctic Ocean and in the oceans around Antarctica. The local amount changes with the season, but at any given time sea ice worldwide covers an area larger than the North American continent.
In the Arctic Ocean, floating sea ice (as opposed to ice shelves, which generally remain attached to the glacier that produced them) covers on average 14 to 16 million square kilometers in late winter and 7 to 9 at the end of summer. In Antarctica, sea ice covers from 17 to 20 million square kilometers in late winter; only about 3 to 4 million square kilometers remains at the end of summer.
The seasonal sea ice cycle is a natural phenomena that affects biological habitats and human activities alike. It's important that scientists study and understand the cycle, which is affected a lot more by the sun and the Earth's orbit around it than by human activities.
It's pretty easy, as the Minnesota duo will no doubt show us, to grab a few short-term observations of changes in sea ice or glaciers and allege catastrophic global warming is taking place. The facts are a lot less convenient, as facts often are ... but it's high time the scaremongers and their allies in the media face up to them.
Jay Lehr, Ph.D. (firstname.lastname@example.org) is science director for The Heartland Institute.