In 2010, at the height of his transition from failed primary candidate to Republican Party nominee, Mitt Romney released “No Apology.” The book, part memoir and part policy platform, offers—in light of profound skepticism on the right—a moderately progressive stance on climate change. “I believe that climate change is occurring,” Romney wrote. “I also believe that human activity is a contributing factor. I am uncertain how much of the warming, however, is attributable to man and how much is attributable to factors out of our control.”

The two-year period that began with No Apology and ended with the Republican National Convention this month witnessed radical changes in Romney’s position on climate change. His climate policy is marked by a crucial linguistic shift: rather than use the neutral and scientifically accurate terminology of “climate change,” Romney now refers to “global warming.” This switch is not inconsequential. All too often, climate change deniers pillory climate science by mocking cold temperatures and extreme weather events as betrayals of global warming. Furthermore, Romney has gone from acknowledging the role of human activity, to downplaying it, to almost ignoring it altogether. Romney’s slide into the empty rhetoric of the right’s climate denial is a lamentable decline for a man who once held reasonable views on what we view as the greatest existential threat to our planet.

Romney’s shortsighted and uninformed bombast obscures the remarkable scientific consensus on climate change. A report released Tuesday by the Better Future Project examines the climate views of scientists from Brigham Young University and Harvard, the two institutions from which he holds degrees. Of BYU professors who have published on climate science in peer-reviewed journals, 86% agree with the scientific consensus on climate change; a full 100% of Harvard professors do. Romney is neglecting the expertise of both of his alma maters and other universities.

Romney’s repeated shifts on climate change have not gone unnoticed. Today, tens of thousands of petition signatures, collected as a challenge to Romney to “articulate his plan for addressing the most urgent issue facing humanity,” will be delivered to his campaign headquarters in Boston. This effort, coordinated by activist William E. McKibben ’82 and 350.org, is testimony to the issue’s unparalleled salience for our generation. The relative lack of debate on climate change between President Obama and Romney betrays grassroots support for swift and decisive attempts to ameliorate its effects.

We believe that behind Candidate Romney stands a man who still holds the reasoned views on climate change he expressed just two years ago. Romney has shifted his views to an untenable position that ignores the gravity of the climate crisis. Without any scientific evidence to support this reversal, we can only assume that Romney caved to pressure from a vocal minority that is locked in denial.

At the RNC, Romney blithely said, “President Obama promised to begin to slow the rise of the oceans and to heal the planet. My promise is to help you and your family.” Climate change, despite his comment that “they do not call it America warming, they call it global warming,” is a matter of both American values and family values. Climate change determines the sort of world in which we will live our lives, in which Mitt Romney’s grandchildren will live their lives, and in which the families Romney prides himself on helping will live their lives. Romney has staked his campaign’s ideology on leadership and responsibility; climate change, more so than any other issue, demands those two qualities.

That the discussion over climate change has been reduced to ill-informed sound bites is a disservice to the American public. We call on Mitt Romney to acknowledge the scientific consensus on anthropogenic climate change and provide the electorate with a concrete plan to tackle its effects. Addressing climate change does not spell economic or geopolitical doom for the United States; rather, it is a prime opportunity to reinvigorate the energy industry, strengthen national security, and usher in an era of technological innovation. Only through mature dialogue can we reframe the way in which this country is a leader amongst nations and a responsible steward of limited global resources.

Daniel Z. Wilson '14 is a history of science concentrator in Currier House. Kristen J. Wraith '14 is an environmental science and public policy concentrator in Dunster House. They are the co-Chairs of the Harvard Environmental Action Committee.