Opponents of Global Warming...

Reasons given by opponents of the global warming theory from the online encyclopedia Wikipedia:

"Some of the assertions made in opposition to the global warming theory include:
IPCC draws firm conclusions unjustified by the science, especially given the acknowledged weakness of cloud physics in the climate models. For example, even those who accept that there is a warming trend point out that there is a big difference between correlation and causality. In other words, just because temperatures have generally been rising since the beginning of the Industrial Revolution, that doesn't necessarily mean that the Industrial Revolution has caused the change in temperature (see post hoc, ergo propter hoc argument). On the other hand, the period since the beginning of the Industrial Revolution has indeed produced ever-growing "urban heat islands" (see below) that could be skewing temperature measurements that indicate the recent warming.

Using "consensus" as evidence is an appeal to the majority argument rather than scientific discussion. Ergo, because the issue has become so politicized, it is suspected that climatologists who disagree with the consensus as it is may be afraid to speak out for fear of losing their positions or funding.

Consensus is further compromised in this field of study due to students being attracted to the field by their belief that something should be done about global warming. They complete their education and add their voices to the consensus, which gives a perceived bias.

Earth's climate has been both colder and warmer than today, and these changes are adequately explained by mechanisms that do not involve human greenhouse gas emissions. There is no significant global warming relative to the expected natural trends.

CO2 in the atmosphere is mainly volcanic in origin, accounting for 97% of the CO2 found in the atmosphere, most of which travels to the oceans. Estimates at CO2's effectiveness as a greenhouse gas vary, but are generally around 10-100 times lower than water weight for weight, leaving a "net" greenhouse effect of man-made CO2 emissions at less than 1%.

Climate science can not make definitive predictions yet, since the computer models used to make these predictions are still evolving and do not yet take into account recently discovered feedback mechanisms. Climate models will not be able to predict the future climate until they can predict solar and volcanic activity.

Some global warming studies have errors or have not been reproduced. Global temperatures are directly related to such factors as: sunspot activity (an 11-year cycle).

The concern about global warming is analogous to the concern about global cooling in the 1970s. The concern about global cooling was unnecessarily alarmist. The concern about global warming is equally alarmist.

Some opponents of global warming theory give more weight to data such as paleoclimatic studies, temperature measurements made from weather balloons, and satellites which they claim show less warming than surface land and sea records, though early balloon records have been shown to be possibly erroneous due to mechanical design flaws in the sensors.

Opponents tend to define themselves in terms of opposition to the IPCC position. They generally believe that climate science is not yet able to provide us with solid answers to all the major questions about the global climate.

Opponents frequently characterise supporters arguments as alarmist and premature, so as to emphasize what they perceive as the lack of scientific evidence supporting global warming scenarios.

Opponents also say that if global warming is real and man-made, no action need be taken now because:
Future scientific advances or engineering projects will remedy the problem before it becomes serious and for less money.
A small amount of global warming would be benign or even beneficial, as increased carbon dioxide would benefit plant life, thus potentially becoming profitable for agriculture world-wide.
There is a distinct correlation between GDP growth and greenhouse gas emissions. A cutback in emissions might lead to a decrease in the rate of GDP growth."