I am a “climate change convert.”
Like many conservatives, I was traditionally skeptical of the science supporting anthropogenic global warming (AGW).
Today, I am skeptical no longer. Like conservative blogger D.R. Tucker, on this issue, I was ultimately “defeated by facts.”
According to Tucker’s article “Confessions of a Climate Change Convert” on FrumForum, reading the 2007 Fourth Assessment Report of the Intergovernmental Panel on Climate Change was the critical moment in his conversion process.
In my own case, I finally reached a point where I could no longer in good conscience deny the implications of the cumulative weight of so large a corpus of evidence.
That body of evidence is extensive, and growing. For example, in 2010 the National Academy of Sciences issued what its president, Ralph J. Cicerone, deemed “the most comprehensive report ever on climate change.”
The report echoes many of the same findings as the earlier 2007 IPCC report that played a key roll in Tucker’s conversion but includes five additional years’ worth of evidence and data. And in 2010, the Pentagon identified AGW as a threat to our nation’s security in its Quadrennial Defense Review for the first time.
As a practicing Roman Catholic, another critical element for me was the leading roll being played by Pope Benedict XVI and the Catholic Church in articulating the moral imperative to address AGW.
For example, in May a working group at the Pontifical Academy of Sciences issued a declaration calling on all people of good will “to recognize the serious and potentially irreversible impacts of global warming caused by the anthropogenic emissions of greenhouse gases and other pollutants, and by changes in forests, wetlands, grasslands, and other land uses.”
Pope Benedict XVI highlighted the “problems associated with climate change” and the need for collective action to address them in his January, 2010 World Day of Peace message. And the Pope has previously stated that “preservation of the environment, promotion of sustainable development and particular attention to climate change are matters of grave concern for the entire human family.”
Taken as a whole, Catholic thought and teaching on the environment demonstrated to me that caring for the natural world, and an ethic of responsible stewardship towards it, were integral components of an authentically pro-life worldview.
In the end, my own reading and research on AGW made the following conclusions inescapable: today, there is no debate in the scientific community about whether the Earth is warming — it is.
There is also a nearly unanimous consensus that human activity is responsible for this warming. There is some debate, on the margins, over the severity of the consequences that will inure from this and whether we can take any remedial measures that will slow, stop, or reverse this process. The consensus position, however, is clear — AGW will probably have a significant negative impact on human civilization and the natural world, and there are practical steps that could be taken now to avoid this fate. Given the foregoing, addressing AGW today is an ethical and moral imperative. Failing to do so is a repudiation of our responsibilities both to each other, and most particularly, to future generations. It is a breach of faith, trust, and duty, of enormous magnitude.
Regrettably, while the case for AGW has become increasingly more persuasive over the past several years, and the need for immediate action ever more apparent, public opinion in the United States has been trending in the opposite direction. 
There are several explanations for this. Few of us (myself included) possess the technical expertise or knowledge required to independently assess and analyze scientific research, reports, or peer reviewed literature. The climate denial industry has exploited this by endeavoring to create “doubt” in the minds of Americans, despite the fact that no reasonable grounds for doubt remain.
At the same time, the radicalization of the political right, and the rise to prominence of an extreme form of libertarianism within its ranks, has made the rejection of proven science in favor of a form of ideologically driven magical thinking a required element of its political orthodoxy.
The scientific evidence, however, cannot be wished away.
Today, we must work with renewed vigor to better educate the public on the threat posed by AGW, and to build support for policies designed to eliminate or mitigate it, while there is still time. 
(Michael Stafford can be reached at anupwardcalling@yahoo.com.)