Some of these people are pushing back hard against the assertion that human-caused global warming is a "fact." From the Wall Street Journal:
In September, Nobel Prize-winning physicist Ivar Giaever, a supporter of President Obama in the last election, publicly resigned from the American Physical Society (APS) with a letter that begins: "I did not renew [my membership] because I cannot live with the [APS policy] statement: 'The evidence is incontrovertible: Global warming is occurring. If no mitigating actions are taken, significant disruptions in the Earth's physical and ecological systems, social systems, security and human health are likely to occur. We must reduce emissions of greenhouse gases beginning now.' In the APS it is OK to discuss whether the mass of the proton changes over time and how a multi-universe behaves, but the evidence of global warming is incontrovertible?"And:
many young scientists furtively say that while they also have serious doubts about the global-warming message, they are afraid to speak up for fear of not being promoted—or worse. They have good reason to worry. In 2003, Dr. Chris de Freitas, the editor of the journal Climate Research, dared to publish a peer-reviewed article with the politically incorrect (but factually correct) conclusion that the recent warming is not unusual in the context of climate changes over the past thousand years. The international warming establishment quickly mounted a determined campaign to have Dr. de Freitas removed from his editorial job and fired from his university position. Fortunately, Dr. de Freitas was able to keep his university job.Global warming alarmists have indeed engaged in all sorts of dirty tricks, from trying to keep anti-global warming papers out of the journals to gaming the job market to make warming critics unemployable. They probably think that this is necessary, given the great wealth and political power of the fossil fuel industries and their allies. But it is wrong and it is only hurting their cause.
The good news is that scientists are a hard lot to bully, and in modern science the side with the data almost always wins in the end. The bad news is that modeling the climate is very, very hard, and we won't really know if our CO2 emissions will lead to a climate disaster until after it occurs.