UNITED STATES - APRIL 16: Candidate for U.S. Senate Michelle Nunn speaks to attendees at her meet and greet event in Shellman, Ga., on Wednesday, April 16, 2014. (Photo By Bill Clark/CQ Roll Call)

WASHINGTON -- While Republican Senate candidates are nearly unanimous in their desire to either ignore or deny the existence of global warming, the major Democratic Senate candidates this cycle are more of a mixed bag.

Those in tough races in more conservative-leaning states avoid the issue of global warming or climate change on their websites. They include Sens. Kay Hagan (N.C.), Mark Begich (Alaska), Mark Pryor (Ark.) and Mary Landrieu (La.), as well as Kentucky candidate Alison Lundergan Grimes.

Those hailing from more traditionally Democratic states fully embrace the need to confront the issue. They include Sens. Al Franken (Minn.), Ed Markey (Mass.), Cory Booker (N.J.) and Jeff Merkley (Ore.). But in swing states some candidates also discuss the issue on their websites, such as Sen. Jeanne Shaheen of New Hampshire, whose website touts the senator’s efforts to “confront the global threat of climate change.”

Other Democrats don’t address the issue quite as directly. Rep. Gary Peters, who is running for Michigan's open Senate seat, touts that he has “fought for clean air and clean water in Michigan communities” without mentioning “climate change.” Rep. Bruce Braley, the Democratic candidate for Iowa's open Senate seat, also does not refer directly to climate change on his campaign website, but he discusses his support for the Renewable Fuel Standard as a way to make “clean energy progress.”

And then there is Michelle Nunn, the Democratic Senate candidate running in Republican-leaning Georgia. She goes squarely at the matter on her website: “We must continue to decrease our reliance on foreign oil and confront the challenges of climate change.”

Nunn's website continues: