Global warming true or false?

In 1996, The United Nations presented three Intergovernmental Panel on Climate Change (IPCC) reports, these reports claimed to have the endorsements of 2,500 scientists, creating the "scientific consensus" that President Clinton and Vice President Gore always refer to. In the year 1995, skeptical scientists signed the Leipzig Declaration on Global Climate Change. The declaration states that they "cannot subscribe the so-called "scientific consensus" that envisages climate catastrophes and advocates hasty actions." 1 With two extremely opposite opinions on this subject by credible scientists from all over the globe, how do you make the decision of who is right and who is wrong?

The IPCC reports claim to have the endorsement of 2,500 scientists; however, this turns out to be a great exaggeration, for "most of the several hundred listed "contributors" are simply specialists who allowed their work to be cited, without necessarily endorsing the other chapters."2 Among these scientists, there are very few who are actually climate scientists, compared to the 100 climate scientists who signed the Leipzig Declaration. Among the few IPCC climate scientists, there are some who "have expressed doubts about the validity of computer models and about the main IPCC conclusion"2 for "unannounced and possibly unauthorized text changes"3 were made to the reports and "some very pertinent information had disappeared between final approval and printing."3 Three independent surveys were taken of IPCC contributors and reviewers, and they each found that "about half did not support the Policymakers' Summary."2

We must decide individually and as a nation whether the data used was credible or not. One of the leading authors of a recent IPCC report, T. M. L. Wigley, along with R. Richels and R. J Edmonds, calculated the effects of unchecked carbon dioxide emissions, and found "a spectacular refutation of the IPCC's apocalyptic scenario."4 He calculated 550...