A group of the country’s top scientists say that the Earth definitely is getting hotter, that human activity is driving it, and that, unless dramatic measures are taken, the planet’s water supply, sea levels, coral reefs, etc. will be changed forever.

So what else is new?  

Well, actually, this time the National Academy of Sciences is talking tough.  In response to a request from Congress, it has released three reports that say in no uncertain terms that we can no longer afford to have industry doing “business as usual” and that Congress must enact a carbon tax or “carbon pricing system” to stop the rise in greenhouse-gas emissions.

That has to happen if the country is to have any hope of slashing carbon emissions to the level the scientists think is necessary by 2050 — almost an 80 percent reduction from current projections.  If it doesn’t, life in the U.S. could be changed in ways that most Americans can’t imagine.  As Thomas Maugh writes in the Los Angeles Times

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They also lay out a series of potential ways to adapt to inevitable changes, such as shifting vulnerable populations away from coasts and finding ways to protect the limited water supplies in the Southwest.

What ultimately may be needed is a profound shift in the way the average American thinks about climate change. Writes Andrew Revkin in the New York Times’ Dot Earth blog:

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A situation of this sort requires aggressive work on multiple fronts, the authors conclude. Even as far more effort is put into improving analysis of the climate system, monitoring changes, and forecasting what is to come, the country must also work to build the intellectual capacity not only to do the science but to have such information meaningfully incorporated in policies at scales down to the town manager.

The scientists acknowledge there’s still a lot of uncertainty when it comes to predicting how much seas will rise or how different regions will be affected. But that doesn’t justify more stalling.  As The New Republic‘s Bradford Plumer puts it:

The … report is pretty clear that there are still plenty of gaps in our knowledge about the climate system, but rather than use that as an excuse to stop obsessing — as many skeptics would urge — it sensibly suggests that maybe we should try to fill in those gaps.

You’re getting warmer

But wait, there’s more. A report published today in the journal Nature presents the most comprehensive evidence to date that the world’s oceans are getting warmer. The study concludes that based on temperature data gathered by 3,200 free-floating sensors over the past two decades, there’s no question that the seas are heating up. And that means the rest of the Earth is, too.

Writes Steve Connor in The Independent:

The findings are important because ocean temperatures are seen as a more reliable and convincing signal of global warming than land-based measurements, which are prone to huge variability. This is due to the fluctuating influences of the weather and the spread of cities, which can artificially increase local terrestrial temperatures by the urban “heat island” effect.

What makes this study so noteworthy, as the San Francisco Chronicle‘s David Perlman points out, is that it’s based on far more extensive and sophisticated measurements than in the past.

The results … are far more accurate than earlier ocean studies, which resulted in a wide range of estimates because temperatures were recorded by ships towing instruments called XBTs — for expendable bathythermographs — and they covered only part of the world.

Deny, deny, deny

And yet, despite the growing mound of incontrovertible evidence of global warming, otherwise perfectly sensible people will continue to say it ain’t so.  You can let that drive you crazy.  Or you can read what Debora MacKenzie, writing for New Scientist, says might be behind it:

The first thing to note is that denial finds its most fertile ground in areas where the science must be taken on trust. There is no denial of antibiotics, which visibly work. But there is denial of vaccines, which we are merely told will prevent diseases — diseases, moreover, which most of us have never seen, ironically because the vaccines work. Similarly, global warming, evolution and the link between tobacco and cancer must be taken on trust, usually on the word of scientists, doctors and other technical experts who many non-scientists see as arrogant and alien.

More alien than Glenn Beck?