Target, Best Buy, General Mills and Cargill signed on to the Obama Administration's American Business Act on Climate Pledge last year. They joined some 150 other major corporations.

The firms promised to make significant reductions in their emissions, water use and waste generation. They also vowed to use more clean energy, and take other actions to build more sustainable businesses and tackle climate change.

Yet those Minnesota companies still contribute to politicians who say climate change is a hoax or exaggerated, and who fight efforts to counter it. The companies' combined contributions amounted to about $300,000.

General Mills, for instance, hopes to reduce greenhouse gas emissions by the company and business partners by almost 30 over the coming decade. And by 2050 the food maker aims to cut emissions to a level that scientists believe is sustainable.

In an interview with MPR last year, Chief Sustainability Officer Jerry Lynch said climate change could threaten the company's business.

"We sell food products. So we're very dependent on mother nature continuing to work well. It's core to how we operate," Lynch said.

But about half of the 2016 election cycle contributions the General Mills Political Action Committee reported through mid-September — $100,000 — went to so-called climate deniers. All were Republicans.

For the Best Buy PAC, about a quarter of political contributions went to global warming skeptics. For Target, nearly a third of contributions went to deniers. At Cargill, about 60 percent did.

The companies' combined contributions amounted to about $300,000.

It's a similar story for many other big corporations. Reuters news service recently found that more than a third of the corporate PAC contributions of DuPont, PepsiCo, AT&T, Google and GE were going to climate deniers.

U.S. Rep. Tom Emmer, a Republican, is ranked as one of the top climate deniers. Jim Mone | AP 2015 file

Best Buy, General Mills and Cargill all contributed to Minnesota GOP U.S. Rep. Tom Emmer. Environmental groups rank him as one of the top climate deniers.

"Just because we make these chambers available to Will Steger and the crowd that wants to rely on Al Gore's climate porn doesn't mean that's the way it is," Emmer said during his time as a state lawmaker.

Emmer's office did not respond to repeated inquiries about whether his stance has changed.

Companies say their support for climate change action has to be viewed in context of all their priorities, not just climate change.

Chris Schraeder, director for sustainability communications at Cargill declined an interview request. In a statement, he wrote, "We obviously live in a complex world where a number of issues matter and we have to take all of those into consideration simultaneously. Climate action is an important issue for us and that's one among many others that we take into account when evaluating political contributions."

General Mills said its political action committee is directed by employees, not the company, and supports candidates for a variety of reasons, with most getting support because they represent places where General Mills employees live and work.

Best Buy focuses its public policy advocacy on issues that directly affect competitiveness, said company spokesperson Jeffrey Shelman.

"Our nonpartisan political action committee seeks to support candidates who consider the full range of issues that affect our business and are in a position to implement change," Shelman said. "That said, our environmental track record is extremely strong. We are well on our way to reducing our carbon emissions by 45 percent by 2020.... And we have diverted more than one billion pounds of e-waste from landfills."

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Target says it's working on eight new sustainability commitments, including adding solar rooftop panels to hundreds of stores and diverting 70 percent of store waste to reuse or recycling programs.

"Target has always been — and will continue to be — committed to investing in the social and environmental sustainability of our communities," spokesperson Molly Snyder said in a statement. "Since 2010, Target has been working toward goals to improve our energy efficiency and lower our overall environmental impact. ... We operate best when working with policy makers on both sides of the aisle, even though we may not agree with them on every single issue."

But Emily Southard, campaign director at ClimateTruth.org, argues global warming should be a decisive factor in political contributions. The nonprofit advocacy group says it fights denial, and other factors that block action on climate change.

"Businesses can only prosper in a safe climate. Scientists tell us that without dramatic action to reduce pollution, our world is in serious danger. And supporting politicians who obstruct action is both a moral failing and bad business," Southard said.

But big companies are not single-issue contributors. That's the finding of University of California Santa Barbara political scientist Matto Mildenberger.

Mildenberger has focused his research on climate change and political contributions.

"We see this over and over again. Businesses might prefer climate policy but they have other policies that they care lot more about ... tax policy, regulatory policy," Mildenberger said.

Tax and regulatory policies can quickly affect a corporation's bottom line and, by extension, share price. Global warming far less so. Until climate change is taking money out of shareholders' pockets, a politicians' stance on global warming is unlikely to get a company's top priority.