Don’t look now, but the single most important issue facing all of us is completely absent from the presidential campaign debate. The fate of the earth is literally at stake — and the two candidates aren’t even talking about it.

Did July feel especially warm? Well, it wasn’t just you: This past month was the U.S.’s hottest month on record. In the read of the morning, the New York Times reports:

The average temperature last month was 77.6 degrees — 3.3 degrees above the average 20th-century temperature, the National Oceanic and Atmospheric Administration reported on Wednesday. July thereby dethroned July 1936, which had set the record at 77.4 degrees, the agency said.

[...] A hot July also contributed to the warmest 12-month period ever recorded in the United States, the statistics showed.

Climatologists at the agency noted that by the end of the month, about 63 percent of the nation was experiencing drought conditions, which contributed to the high temperatures.

[...]“This clearly shows a longer-term warming trend in the U.S., not just one really hot month,” [Jake Crouch, a climatologist at the agency’s National Climatic Data Center in Asheville, N.C.,] said.

As Rachel Maddow tweeted, “apparently the actual climate is in on the whole global warming liberal conspiracy.”

All levity aside, though, climate change is here, now, and will have increasingly terrible consequences over the next few decades. Yes, not everyone agrees specific weather events can be tied to to global warming: Jake Crouch refuses to draw that conclusion in the Times article, while climate scientist James Hansen argued this past Sunday in The Post (and in a newly-released paper) that several recent catastrophic heat waves and droughts have “virtually no explanation other than climate change.” But, as the Times article also notes, “a vast majority of scientists agree that such events will become ever more common as the planet warms.”

And yet, climate change is not even being discussed in the presidential race, with the Obama camp refusing to bring it up and the Romney camp arguing — in the face of scientific consensus — that it’s not really a man-made problem. In large part, this skewed debate is the result of the decades-long campaign by the Republican Party and the oil industry to discredit scientists while offering their own pseudo-science, aided by an “objective” media that still refuses to treat climate change denialists like people who believe two plus two equals five.

But liberals can’t absolve themselves of the blame: all too often, they’ve been willing to let Democrats push climate change down the list of priorities. If the president won’t lead on the issue, and if Republicans refuse to acknowledge basic facts, it’s up to rank-and-file liberals to sound the alarm and put climate change front and center in the American political discourse.

* Debate continues raging over Priorities ad: Plenty of excellent commentary out there this morning on the ad suggesting Bain was partly to blame for the death of a steelworker’s wife. Jonathan Cohn makes the central point: Even if the claim is not supported, Obama wants the federal government to guarantee that women like Ms. Soptic have health insurance; Romney doesn’t want that, and even wants to take away from people what Obama has accomplished in this regard. That’s roughly my take, too.

Meanwhile, Michael Kinsley defends the ad, claiming: “It is uncontested that lack of insurance is what killed this woman.” I’m not sure how Kinsley concludes this, but if it could be established, it would change the debate. — gs

* Obama puts women’s health at center of campaign: Obama started his two-day trip through the key swing state of Colorado in Denver, where he was introduced by Rush Limbaugh-target Sandra Fluke. The president accused Republicans of taking America back to “policies more suited to the 1950s than the 21st century,” zeroing in on Romney’s support for getting “rid” of Planned Parenthood and allowing employers to deny contraception to employees.

Obama is substantively right to attack Republicans’ terrible policies on health care for women. Yesterday’s poll of Colorado, which had Obama trailing Romney by five, found the president polling weaker with women than in other swing states. .(More broadly, the widening gender gap — and especially the fact that it’s now also present among non-college women as well as upscale ones — helps explain Obama’s increasing emphasis on these issues. — gs)

* Romney’s nonsensical tax plan: Rumor has it that at least one thesaurus has a picture of Post columnist Robert Samuelson as its antonym for “partisan.”But when it comes to Romney’s tax plan, Samuelson is as baffled as anyone: “[T]he last thing you’d expect Romney to do is embrace a tax plan favoring the super-rich. Which is exactly what he has done...It’s not just that the politics are poisonous. The economics don’t make sense, either...Although the wealthiest 5 percent still pay about 40 percent of federal taxes, it’s questionable whether further reducing their tax burden would bolster the economy.” At this point, it seems the only way for Romney to escape the criticism is to release a new tax plan.

* Even Romney’s experts admit he’d raise middle class taxes: Jim Tankersley caught up with John W. Diamond, “the economist Mitt Romney is holding up as a shield against attacks on his tax plan.” Even Diamond “can’t argue” with the Tax Policy Center’s conclusion that Romney’s plan would have to raise taxes on lower-income Americans (though he does see benefits in the plan).

Bonus: When the Romney camp asked Diamond to model the propoposal, he wasn’t able to “model the full Romney plan, because the Republican’s campaign refuses to identify, even to him, which tax deductions and credits they would cut to make the plan revenue-neutral.”

* Return the Obamacare rebates, Republicans: A powerful challenge to conservatives from E.J. Dionne:

Here’s a chance for all who think Obamacare is a socialist Big Government scheme to put their money where their ideology is: If you truly hate the Affordable Care Act, you must send back any of those rebate checks you receive from your insurance companies thanks to the new law. This is just common sense. If you think free enterprise should be liberated from Washington’s interference, what right does Uncle Sam have to tell the insurers they owe you a better deal? Keeping those refunds will make you complicit with Leviathan.

Furthermore, he asks Romney, if the GOP nominee wants to attack Obama giving states waivers for welfare-to-work programs, “will you please stop talking about your devotion to states’ rights?”

* Republican voting shenanigans take sinister turn in Ohio: At this point, the GOP attack on voter rights (especially minority voter rights) in key swing states is widely known. The latest developments from Ohio, though, flagged by the Nation’s Ari Berman, may reach a new low:

Now, in heavily Democratic cities like Cleveland, Columbus, Akron and Toledo, early voting hours will be limited to 8 am until 5 pm on weekdays beginning on October 1, with no voting at night or during the weekend, when it’s most convenient for working people to vote...Yet in solidly Republican counties like Warren and Butler, GOP election commissioners have approved expanded early voting hours on nights and weekends.

Most of the Republican-pushed voter ID laws have at least had respectable abstract arguments behind them, even if voter fraud is a made-up problem. But there’s no way to see this transparently partisan approach to extending early voting as anything other than an attempt to steal the 2012 election.

* Union hits planned Verizon merger: The Communications Workers of America is up with a new ad in Pennsylvania, Virginia and Washington, D.C., pressuring the Federal Communications Commission not to accept Verizon’s pending cross marketing deal with cable companies, arguing that it will shaft consumers and workers alike. (This has been edited for accuracy.) — gs

* And new Senate polls in Wisconsin, Virginia and Indiana: The Times has new numbers for the Virginia and Wisconsin Senate races: Tim Kaine leads George Allen 48-46, though Allen leads 49 to 41 percent among independents. Tammy Baldwin is tied at 47 percent with Tommy Thompson, and holds leads within the poll’s margin of error against the other two leading Republican contenders, Mark Neumann and Eric Hovde. ( The GOP primary is next week.) Expect these races to stay close until Election Day.

Meanwhile, an internal poll for Democratic Rep. Joe Donnelly’s Senate campaign in Indiana finds him leading Republican nominee Richard Mourdock 41-40. Obviously, as a poll released by the campaign, the numbers should be taken with a grain of salt, but if Mourdock keeps pulling stunts like comparing the Chrysler bailout to slavery, don’t be surprised if external polls start finding similar numbers.

What else?