Of course, this month hasn't been the only warm one in the U.S. this year; every month has in fact been toasty—March absurdly and bizarrely so. And, as noted below, July 2012 was the single hottest month in U.S. history. But allow me to show you; the following two graphs will illustrate that in a far better way than words ever could.

This first shows two things. 1) Based on the left axis, the to-date number of daily high maximum and high minimum temperature records (the red stalagmite-like spikes shooting upward from the center zero line) vs. the to-date daily low minimum and low maximum temperature records (the blue stalactite-like spikes hanging from that line). And 2) based on the right axis, the cumulative number of those records to-date, with high temperature records represented by the red line, and low temperature records by the blue one. The preponderance of red is obvious. Note that, while the blue line showing cumulative cool records has risen fairly slow and steady pace the entire year, the red line showing cumulative heat records has risen at a much faster rate, and alarmingly so at times.



This second graph shows the monthly number ofrecord daily high and low temperatures in the U.S. this year. Again, a quick glance will show that highs dominate, with only August coming anywhere close to something resembling balance:In a stable climate, the number of record highs and record lows would be expected to occur in roughly equal numbers over the long term. But such climatic stability no longer exists; the planet is heating up, so the record high/record low balance is being thrown badly out of whack both here and wlsewhere. As of this writing, the U.S. has seen more than 55,500 record high or high minimum temperatures this year, and a fewer than a relatively paltry 9,600 record low or low maximum temperatures. Andwhat climate change looks like.

Now, so far, of course, we've dealt with just the United States; what about the rest of the planet? Fair question.

Let's start with the Arctic.

This first graph shows the loss of Arctic sea ice volume (that is, ice surface multiplied by ice thickness) since the start of the satellite record in 1979 (from PIOMAS). It doesn't take a rocket scientist—or a climate scientist, for that matter—to see just how close to the center of the graph the current year's red line is. And it doesn't take much imagination to see where it will be in just a small handful of years:



Annual Arctic sea ice volume "death spiral" graph

Annual Arctic sea ice extent "death spiral" graph

Annual Arctic sea ice area "death spiral" graph

Annual percentage loss of maximum Arctic sea ice area

Lots of people liked that graph after I created and published it, so I went ahead and made versions for both Arctic sea ice extent (from the Japan Aerospace Exploration Agency [JAXA] ):...and Arctic sea ice area (from the Arctic Climate Research Unit at the University of Illinois):And speaking of area—which as of this writing is more than 600,000 square kilometers lower than the previous record minimum set just last year—this graph shows the percentage loss of Arctic sea ice area for each year in the record. As of this writing, 83.24% of the ice that existed at this year's peak back in March no longer exists. The rapid escalation of the annual percentages is indication that, not too many years from now, there will be 100% loss of that year's ice. When that happens—and it will—the Arctic will be free of ice for the first time in many tens of thousands of years. If not longer.Fun visualization: as of today, 11,414,749 square kilometers of Arctic sea ice area have reverted to liquid seawater this year. Imagine a meters-thick ice hockey rink larger than the nations of Canada, Mexico, and Japansimply melting into a humongous puddle over the course of just 180 days or so. That's what's happened this year. Or, in tribute to this past summer's fine London games, try this visualization instead: the volume of Arctic ice that melted this past summer is enough to fill more than 7.4Olympic-sized swimming pools.

An ice-free Arctic has already brought about many problems, and it's certain to bring about a lot of far worse ones.That's what climate change looks like.

Now, we obviously know that the United States is warming up at rapid pace, and that the Arctic is warming up even faster. But what about the rest of the planet?

Following is my (mostly) faithful reproduction of a monthly graph produced by Dr. Roy Spencer and Dr. John Christy. (Original here.) Now, as some of you may be aware, Spencer and Christy are widely know for being particularly vocal climate change contrarians. So when you look at their version of the chart, you'll see they've overlaid it with a 4th-order polynomial trendline (that horizontally-stretched 'S' curve running the width of the chart). By their own admission, this trendline is "meaningless", leading one to assume that it was placed there only to make it appear as though global temperatures have stabilized over the past several years (which they most assuredly have not). The thing is, however, any other trendline Spencer and Christy could have chosen—exponential, linear, logarithmic, or 2nd, 5th, or 6th order polynomial—would have clearly shown the steady warming that's been going on. (I myself have included a 2nd-order polynomial trendline to demonstrate that.)



UAH Satellite-Based Temperature of the Global Lower Atmosphere

When even a graph produced by climate contrarians complete undermines the primary contrarian argument—that the earth isn't actually warming—you know things have turned ugly. That, too, is what climate change looks like.

I thought I might close by running down a randomly-selected list of a few of this year's weather extremes some of you may have missed. In no particular order:

Just last month, Europe experienced its most severe heat wave since the massive one in the summer of 2003. In fact, many locations there recorded temperatures even hotter than they saw in 2003. For instance, all-time national heat records were set in the Czech Republic, Moldova, and Montenegro. And virtually every weather site in the Pyrenees and along the French and Spanish border recorded its warmest temperature ever. (Source)

Speaking of Europe: for the first time on record, many of Europe's highest peaks—including the Matterhorn—lost all of their snow cover (aside from glaciers). (Source)

On August 14, Needles, CA, experienced rain while the temperature was 115°F (46.1°C). That's the hottest temperature at which rainfall has ever been recorded anywhere on earth. (Source)

Also in August, Mtunzini in South Africa reached 42.5°C (108.5°F). South Africa is, of course, in the Southern Hemisphere, where August is winter. (Source)

On July 12, the overnight low temperature at Death Valley, CA, was 107°F (41.7°C), after hitting a high the day before of 128° (53.3°C). That ties the record for the warmest daily low temperature ever recorded anywhere on the planet. It also breaks the world record for the warmest one-day average temperature, with 117.5°F. (Source)

temperature at Death Valley, CA, was 107°F (41.7°C), after hitting a high the day before of 128° (53.3°C). That ties the record for the warmest daily low temperature ever recorded anywhere on the planet. It also breaks the world record for the warmest one-day average temperature, with 117.5°F. (Source) New Mexico saw its largest wildfire ever this year, when the Whitewater-Baldy complex fire consumed nearly 300,000 acres. That was nearly double the size of the state's previous largest wildfire ever, last year's Las Conchas blaze. (Source)

In Beijing, 6" of rain fell, the largest one-day rainfall that city has seen in many hundreds of years of recordkeeping. 77 people died as a result of the subsequent flooding. (Source)

Asia saw a new all-time continental record high temperature of 53.6°C (128.5°F) at Sulaibya, Kuwait. (Source)

Between 1871 and 2012, Chicago recorded a total of 18 days with a temperature of 80 degrees or higher in the month of March. Eight of those occurred in March of 2012. (Source)

In the first week of March, 2012, the Hawaiian island of Oahu was pummelled by hailstones 4" and greater in diameter, the largest ever in that state. The previous largest hailstone recorded in Hawaii was 1". (Source)

Las Animas, CO, reached 114 degrees on June 24, 2012. This is the hottest temperature ever recorded in the state of Colorado. (Source)

Denver recorded its greatest 3-day February snowfall ever. (The city's heaviest snows have historically been in late March and early April.) Weather records in Denver go back to 1872. (Source)

In June, torrential rains in China led to the evacuation of 5,000,000 people, 67 deaths, and losses in the billions of dollars. (Source)

Europe suffers its worst cold spell in a quarter of a century, killing more than 650. (Source)

In June, Colorado's Waldo Canyon Fire consumed 165,000 acres and 700 homes. It was the most destructive wildfire in that state's history. (Source)

Massive flooding struck large parts of Australia in February. (Source)

In May, Brazil was suffering through its worst drought in at least 50 years. (Source)

April ended the warmest 12-month period ever for the continental United States, but... (Source)

...that record lasted only a month, as May ended the warmest 12-month period ever for the continental United States, although... (Source)

...that record, too, was short-lived, as June ended the warmest 12-month period ever for the continental United States. But—you guessed it— (Source)

...that record, too, lasted only a month, as July ended the warmest 12-month period ever for the continental United States. In fact, July was the single hottest month ever recorded in the United States. (Source)

Washington, DC, reached its hottest June day in 142 years of recordkeeping when the temperature hit 104. This broke the previous record of 102 that was set just last June. (Source)

The Sahel suffered through an intense and devastating drought. (Source)

Two weeks' worth of monsoonal rain fell in Manila in less than 24 hours, disrupting the lives of over a million people and killing 11. (Source)

This year saw the warmest March on record in the continental U.S. (Source)

I could go on and on, of course; as Jimmy Durante used to say, I got a million of 'em. But I'll stop now, because that's just too much ugliness for even me—and I like extreme weather.

But you should know this: it's going to get a whole hell of a lot uglier. And that's what climate change looks like...

Note: you can find updated versions of the charts and graphs above, plus others, at my website Pettit Climate Graphs.

On a final note: those interested in longstanding and famous extreme weather records might be interested in my diary slated for publication just after 9:00 EDT tomorrow morning (Thursday, September 13). I apologize for the tease, but there's an embargo against writing anything further than that until then.

Thanks, everyone, for the (mostly) kind response. It's good to know that others find such information useful, if disturbing...