We don’t know what we don’t know. For me, that’s the most shocking facet of the UCS report, A Climate of Corporate Control.

Most folks are not surprised to hear that corporations tried to influence the public debate on climate policy. What is surprising are the many avenues they took to do that, and how little we really know about these efforts.

Opportunities for wealthy special interests to skew the climate debate and to elect climate deniers to Congress and the White House can take many forms.

The most visible form is straight-up political contributions. That money is publicly disclosed.

But a lot more secret money has been spent to influence the climate debate.

Our survey of 28 S&P 500 publicly traded corporations that have engaged on climate issues revealed that many of them used indirect ways to subvert the climate policy discussion. Often the channels they used –contributions to think tanks, comments to government agencies like the Environmental Protection Agency questioning the science behind climate change, or membership on the boards of groups that strongly oppose any government efforts to reduce the impact of global warming – received little scrutiny. This problem was particularly acute when corporations that seemed to be public advocates for climate science actually were saying quite the opposite in other forums.

It shouldn’t take UCS analysts and researchers, toiling away for months, to uncover this disconnect. That’s what makes the problem of secret spending so insidious: It makes it far easier for those individuals, groups and corporations with an anti-science agenda to hide their participation, spread disinformation, and not be held accountable for their actions.

Campaign finance law can get really complicated. But in essence, what we have now, thanks in part to a recent Supreme Court decision, is a world where corporations and wealthy individuals can give unlimited funds to influence political and public policy debates, and a good portion of those funds can remain secret.

For example, the Los Angeles Times described a recent ad that accused the Obama Administration of squandering billions of taxpayer dollars subsidizing “green energy” industries that created jobs abroad, not at home. The ad’s message attacks the President, but it also undermines government policies that support green energy.

The group, Americans for Prosperity, spent more than $6 million to air the ad, which journalist Doyle McManus termed “highly misleading – a slick pastiche of untruths, half-truths and exaggerations.”

The ad is bad enough. What is worse is that we don’t know the source of funds for that ad. Which corporations and individuals ponied up the funds to run it?

The trends our report documents likely will only get worse during the election year, as electoral politics mix with an anti-science and anti-climate message that confuses the public and prevents us, as a country, from addressing the challenges of climate change in a meaningful way.

There is no quick fix to the problem. But one proposal before Congress would help shed some badly needed light on some of these practices.

The Disclosure of Information on Spending on Campaigns Leads to Open and Secure Elections Act of 2012 (DISCLOSE Act), sponsored in the House by Rep. Chris Van Hollen (D-MD), and in the Senate by Senator Sheldon Whitehouse (D-RI) would make it much harder for corporations, unions and other groups to hide their political expenditures, direct or indirect. Under Rep. Van Hollen’s bill, corporations also would have to disclose their political spending to shareholders.

There are some signs that Sen. John McCain (R-AZ), a longtime supporter of campaign finance reform, might be willing to support the bill.

We can only hope that Sen. McCain does, once again, take a leadership position on this important issue. Disclosure has always been a subject on which both political parties could agree. We all are better off when we know the identity of those individuals and corporations that are influencing public policy in profound and undemocratic ways.

Celia Wexler is a senior Washington representative in the Scientific Integrity program at UCS.