[sjastro]

Originally Posted by Argonavis

Science isn't done by survey, although I appreciate what you are trying to convey. I prefer to make up my own mind based on the evidence.

Surveys themselves are subject to abuse. This survey is reporting on "do you believe" rather than "is there solid evidence for".

If the survey question is in a "do you believe" format (as most survey questions are), the answer is obviously in the same format.

That point aside, "In 1991 only a minority (41%) of climate scientists agreed that then-current scientific evidence “substantiates the occurrence of human-induced warming,” compared to three out of four (74%) today." This is a much more definitive statement.

Originally Posted by Argonavis

The survey reports "Ninety-seven percent of the climate scientists surveyed believe “global average temperatures have increased” during the past century." This is not surprising. These are human beings who are influenced by the popular culture, just like everyone else.

They wouldn't be scientists then. When is scientific modelling and the conclusions generated based on fads.

Incidentally. "Five percent of climate scientists say they have been pressured by public officials or government agencies to “deny, minimize or discount evidence of human-induced global warming,” Three percent say they have been pressured by funders, and two percent perceived pressure from supervisors at work.

Just three percent report that they were pressured by public officials or government agencies to “embellish, play up or overstate” evidence of global warming: Two percent report such pressure from funders, and two percent from supervisors."

Let's assume all these scientists have been influenced, that still leaves a large percentage with unadulterated opinions.

Originally Posted by Argonavis

The earth's average global temperature is believed to have increased by 0.4 °C ± 0.6 °C over the last 100 years. The error bars are bigger than the movement! There is also numerous factors affecting the accuracy of these measurements. Most of these increases were prior to the 1950's. These numbers are subject to much debate.

This gets me back to my original post. The NASA GISS data posted by Bert shows a very different picture.

Originally Posted by Argonavis

The real issue is that the data is ambiguous, the science uncertain, and the future unknown.

The issue for me has been whether global warming is a natural or human induced event. The Greenhouse effect predicts that the temperature of the lower stratosphere would decrease where as increased solar activity would have an opposite effect.

Measurements indicate that the temperature is decreasing hence I've made up my mind.

Regards

Steven