Lee Gerhard is a geologist and a reviewer for the Intergovernmental Panel on Climate Change (IPCC). Here’s what he has to say about greenhouse gases, CO2 concentrations and effect, Arctic and Antarctic ice, polar bears, human influence on global temperature and so on (from Icecap):

It is crucial that scientists are factually accurate when they do speak out, that they ignore media hype and maintain a clinical detachment from social or other agendas. There are facts and data that are ignored in the maelstrom of social and economic agendas swirling about Copenhagen. Greenhouse gases and their effects are well-known. Here are some of things we know:

• The most effective greenhouse gas is water vapor, comprising approximately 95 percent of the total greenhouse effect.

• Carbon dioxide concentration has been continually rising for nearly 100 years. It continues to rise, but carbon dioxide concentrations at present are near the lowest in geologic history.

• Temperature change correlation with carbon dioxide levels is not statistically significant.

• There are no data that definitively relate carbon dioxide levels to temperature changes.

• The greenhouse effect of carbon dioxide logarithmically declines with increasing concentration. At present levels, any additional carbon dioxide can have very little effect.

We also know a lot about Earth temperature changes:

• Global temperature changes naturally all of the time, in both directions and at many scales of intensity.

• The warmest year in the U.S. in the last century was 1934, not 1998. The U.S. has the best and most extensive temperature records in the world.

• Global temperature peaked in 1998 on the current 60-80 year cycle, and has been episodically declining ever since. This cooling absolutely falsifies claims that human carbon dioxide emissions are a controlling factor in Earth temperature.

• Voluminous historic records demonstrate the Medieval Climate Optimum (MCO) was real and that the “hockey stick” graphic that attempted to deny that fact was at best bad science. The MCO was considerably warmer than the end of the 20th century.

• During the last 100 years, temperature has both risen and fallen, including the present cooling. All the changes in temperature of the last 100 years are in normal historic ranges, both in absolute value and, most importantly, rate of change.

Contrary to many public statements:

• Effects of temperature change are absolutely independent of the cause of the temperature change.

• Global hurricane, cyclonic and major storm activity is near 30-year lows. Any increase in cost of damages by storms is a product of increasing population density in vulnerable areas such as along the shores and property value inflation, not due to any increase in frequency or severity of storms.

• Polar bears have survived and thrived over periods of extreme cold and extreme warmth over hundreds of thousands of years extremes far in excess of modern temperature changes.

• The 2009 minimum Arctic ice extent was significantly larger than the previous two years. The 2009 Antarctic maximum ice extent was significantly above the 30-year average. There are only 30 years of records.

• Rate and magnitude of sea level changes observed during the last 100 years are within normal historical ranges. Current sea level rise is tiny and, at most, justifies a prediction of perhaps ten centimeters rise in this century.

The present climate debate is a classic conflict between data and computer programs. The computer programs are the source of concern over climate change and global warming, not the data. Data are measurements. Computer programs are artificial constructs.

Public announcements use a great deal of hyperbole and inflammatory language. For instance, the word “ever” is misused by media and in public pronouncements alike. It does not mean “in the last 20 years,” or “the last 70 years.” “Ever” means the last 4.5 billion years.

For example, some argue that the Arctic is melting, with the warmest-ever temperatures. One should ask, “How long is ever?” The answer is since 1979. And then ask, “Is it still warming?” The answer is unequivocally “No.” Earth temperatures are cooling. Similarly, the word “unprecedented” cannot be legitimately used to describe any climate change in the last 8,000 years. …

I have been a reviewer of the last two IPCC reports, one of the several thousand scientists who purportedly are supporters of the IPCC view that humans control global temperature. Nothing could be further from the truth. Many of us try to bring better and more current science to the IPCC, but we usually fail. Recently we found out why. The whistleblower release of e-mails and files from the Climate Research Unit at East Anglia University has demonstrated scientific malfeasance and a sickening violation of scientific ethics. …

From The Vancouver Sun:

Ian Plimer has outraged the ayatollahs of purist environmentalism, the Torquemadas of the doctrine of global warming, and he seems to relish the damnation they heap on him.

Plimer is a geologist, professor of mining geology at Adelaide University, and he may well be Australia’s best-known and most notorious academic.[He] is an unremitting critic of “anthropogenic global warming” — man-made climate change to you and me — and the current environmental orthodoxy that if we change our polluting ways, global warming can be reversed. It is, of course, not new to have a highly qualified scientist saying that global warming is an entirely natural phenomenon with many precedents in history. Many have made the argument, too, that it is rubbish to contend human behaviour is causing the current climate change. And it has often been well argued that it is totally ridiculous to suppose that changes in human behaviour — cleaning up our act through expensive slight-of-hand taxation tricks — can reverse the trend. But most of these scientific and academic voices have fallen silent in the face of environmental Jacobinism. Purging humankind of its supposed sins of environmental degradation has become a religion with a fanatical and often intolerant priesthood, especially among the First World urban elites.

But Plimer shows no sign of giving way to this orthodoxy and has just published the latest of his six books and 60 academic papers on the subject of global warming. This book, Heaven and Earth — Global Warming: The Missing Science … presents the proposition that anthropogenic global warming is little more than a con trick on the public perpetrated by fundamentalist environmentalists and callously adopted by politicians and government officials who love nothing more than an issue that causes public anxiety [so that they can have yet another excuse to control our lives – JB].

 While environmentalists for the most part draw their conclusions based on climate information gathered in the last few hundred years, geologists, Plimer says, have a time frame stretching back many thousands of millions of years. The dynamic and changing character of the Earth’s climate has always been known by geologists. These changes are cyclical and random, he says. They are not caused or significantly affected by human behavior. Polar ice, for example, has been present on the Earth for less than 20 per cent of geological time, Plimer writes. Plus, animal extinctions are an entirely normal part of the Earth’s evolution.

 (Plimer, by the way, is also a vehement anti-creationist and has been hauled into court for disrupting meetings by religious leaders and evangelists who claim the Bible is literal truth.)

Plimer gets especially upset about carbon dioxide, its role in Earth’s daily life and the supposed effects on climate of human manufacture of the gas. He says atmospheric carbon dioxide is now at the lowest levels it has been for 500 million years, and that atmospheric carbon dioxide is only 0.001 per cent of the total amount of the chemical held in the oceans, surface rocks, soils and various life forms. Indeed, Plimer says carbon dioxide is not a pollutant, but a plant food. Plants eat carbon dioxide and excrete oxygen. Human activity, he says, contributes only the tiniest fraction to even the atmospheric presence of carbon dioxide.

There is no problem with global warming, Plimer says repeatedly. He points out that for humans periods of global warming have been times of abundance when civilization made leaps forward. Ice ages, in contrast, have been times when human development slowed or even declined.

 So global warming, says Plimer, is something humans should welcome and embrace as a harbinger of good times to come.