Go back to May 1997, about seven months before the Kyoto Protocols were negotiated. The Cooler Heads Coalition established its web site, www.globalwarming.org.

It was a savvy move for a group that’s skeptical about the risks of rising temperatures. Even it recognized how universal the term “global warming” was becoming.

It’s a small but telling footnote in the ongoing war of words over the globe’s changing climate – and humanity’s role in it.

Words matter. Perhaps nowhere is this more evident than on the Internet, today’s powerful arbiter of public opinion.

The term global warming predominates as a catch-all phrase for the rise in average global surface temperatures and its consequences.

Scientists say they try to be precise about their choice of words. Global warming is driving a variety of regional climate changes in ways that are not yet completely understood. But today’s rise in global average temperatures, driven predominately by the rise in carbon dioxide emissions, cannot be fully explained by any natural variability in climate.

That’s a mouthful. But it’s essentially what most scientists have in mind when it comes to the terms global warming, climate change, and natural variability.

Scripps Institution of Oceanography’s Richard Somerville.

“The most important consequences of global climate change are local, not global, and certainly not limited to warming,” said Richard Somerville, a climate scientist at the Scripps Institution of Oceanography at the University of California San Diego.

“We climate scientists haven’t yet come up with a term that conveys the full implications, such as rising sea level, greater risk of heat waves, disrupted precipitation patterns, and so on,” Somerville said in an e-mail interview.

Ask others about their choice of terms, and the answers vary as much as the weather.

Myron Ebell, chair of the Cooler Heads Coalition and director of energy and global warming policy at the free-enterprise Competitive Enterprise Institute, says he prefers “global warming” because it describes the general phenomenon of rising average temperatures around the globe. “It’s a sort of general signifier of what the debate is about,” he said.

Myron Ebell chairs the Competitive Enterprise Institute’s Cooler Heads Coalition.

But Ebell also uses the term “global warming alarmists” to castigate former Vice President Al Gore, NASA climate scientist Jim Hansen, and others who he sees as overstating the risks of a warming planet.

The Pew Center on Global Climate Change, which has recruited businesses to get serious about the issue, chose its name a decade ago to present itself as a credible organization with a measured point of view, said Katie Mandes, the center’s director of communications.

“We very much wanted to be a reasonable voice in the debate, and when we started ten years ago the debate was extremely polarized,” Mandes said.

The choice has had its drawbacks. The masses who search the Web go for “global warming” far more than they do “climate change.” And because the Internet is such a powerful cultural force, global warming has become the iconic term for what’s happening to the planet, Mandes and others say.

Nevertheless, the media should be as precise as scientists when choosing language. That’s often difficult, when time is short and space limited.

“I can’t give you a sound bite on it, so therefore it doesn’t work in the public ñ and I’m good at sound bites,” said Stephen H. Schneider, the charismatic and loquacious climate scientist at Stanford University.

So are political strategists, as Frank Luntz showed Republican party faithfuls in a 2003 pre-election memorandum (pdf – 16 pgs). In it, he advised them to use the term “climate change” instead of the more ominous sounding “global warming.”

Vice President Gore, who in his post-Washington life has done more than perhaps anyone to raise the profile of the climate change issue, knows the value of a quick and simple slogan. He says we’re in a “climate crisis.”

This summer, he challenged professional and amateur advertisers alike to come up with ideas for a global advertising campaign, with the aim of accelerating government action to reduce CO2 emissions. Gore is known to be working on another major climate change treatise, for release in the summer of 2008, as the major party political conventions are at full speed.

If it flies, the campaign – the ad campaign, that is – will likely introduce more words and phrases into the climate lexicon, and those too will have plenty of critics and hidden implications.

Journalists might get dizzy from all the spin. All the more reason they’ll need to pay close attention and help their readers sort it all out.

Also see: Rhetoric as an Effective Political Tool: Journalists Need to Beware, Focus on Real Issues