It Was So Hot the Tarmac Melted


It has been really, extremely, record-setting hot here on the US East Coast and in the Midwest. (After the past few weeks, 90 degrees fahrenheit now seems “cool” to me.)

It was so hot that the tarmac melted at Washington’s Reagan National Airport on Saturday. So much for asphalt tarmac, the “foundation of our mighty air network,” being sturdy and stable stuff to plant your feet, let alone an airplane, on, as Megan Garber writes in The Atlantic.

The US Airways plane was taxiing to take off when it was stuck on the tarmac for three hours. Then it became stuck in the tarmac which had softened from the heat. A groove had formed, the airplane sunk into it and at first it could not be removed.

It was 100 degrees Fahrenheit on Saturday which is certainly hot but not the hottest. Garber explains why a “semi-solid surface” like tarmac became “ever-so-slightly less solid” while also pointing out that “our current common surface might not be fully suited to its new, excessively heated environment.”

What is tarmac?

Tarmac, Garber explains, is “an abbreviation for “tarmacadam,” which is itself an abbreviation for “tar-penetration macadam.” Macadamization is a method of road construction in which stones are broken down into smaller chunks that are bound together with a cementing agent (often stone dust mixed with water) and placed atop bare soil. Tarmac contains not only the pulverized stones (which generate a lot of dust) but also coal tar, cement, resin, pitch, and ironworks slag, all smoothed flat by a steamroller.

In the US, petroleum-based pitch is used as a binding agent. The pitch makes the tarmac not quite a solid so repairs are relatively efficient. But, as Garber writes:

Viscoelasticity means that the asphalt is — rather frighteningly — always capable of liquifying. Heat the stuff to around 250 degrees F, and it will become liquid. Cool it back to room temperature, and it will become relatively solid. Again, that’s what’s great about it — and, normally, outdoor temperature is close enough to room temperature that asphalt’s latent meltiness isn’t an issue. Normally, tarmac can function pretty much like concrete. Normally.

The extreme heat this past weekend, after over a week of higher-than-average temperatures, meant that even the tarmac was not the same — was not as solid as it usually is

Climate change means that what seemed solid and stable (airport runways) is not exactly so. So, assuming if — regrettably — hotter temperatures are here to stay, we will need to start rethinking how such changes affect the materials of the things we use and not only for roads and runways: What about bridges and buildings?

Global warming, the melting tarmac at the Reagan Airport shows, is changing our world and its very properties in ways seen and unseen and certainly much felt.


Related Care2 Coverage

As Black Lung Cases Doubled In The Last Decade, The Coal Industry Fought New Health Protections

Americans Want Power Companies To Embrace Renewables

Are Airplane Seats Safe for Overweight Passengers?


Photo by James Cridland


Dale Overall

Certainly hotter than usual in Eastern Ontario despite our usual hot and humid mind numbing summers. Too cold winters and too hot winters what else is new? Meanwhile, the polar ice is melting much more and the polar bears are endangered. So many signs world wide of climate changes and yes, while even in unrecorded times there have been drastic shifts in climates which is normal, how can people ignore the recent drastic changes which impact wildlife, farming and many other things Entire coral reefs are in danger of disappearing as ocean temperatures rise. So many examples of lives being endangered but there are some whom wish to remain blissfully unaware.

Mary B.
Mary B6 years ago

How about coating the runways with heat reflective or white paint. That would help.They could also put down piping to syphen the heat off, then use the heated water to help generate electric, or just heat the water for nearby hotels.Or, if they used 'grey' water in the pipes, it could be drained off into nearby cooling and steralizeing ponds. Im sure there are lots of ways this problem can be turned into a posative. Call in the environmental engineers.

Quanta Kiran
Quanta Kiran6 years ago


Helen K.

I had parking lot sticking to my shoes one day when it hit 117 F. No surprise.

Sandy Erickson
Sandy Erickson6 years ago

Golbal warming is not proven.To prove it we need acurate data going back millions of years...just sayin'...

Titan A.
Titan A.6 years ago

A pavement system that is designed to hold airplance traffic also has the potential to liquify. Seems as though the United States would want a more reliable surface for infrastructure as important as airport runways.

Using portland cement concrete is a rigid and non-flexible pavement that does not breat down under atmospheric heat as does petroleum based pitch. There is a solution available today with technologies that have been around for over one thousand years.

Magyar Girl
Past Member 6 years ago

Climate deniers have all had lobotomies.

Magyar Girl
Past Member 6 years ago

Yes, but remember, there is nothing wrong with the environment!

Ann B.
Ann B6 years ago

so crazy can't think of anything to say.....

Ernest R.
Ernest R6 years ago

@ Mark K.. “Can anyone here point to a time in the Earths history when the climate was NOT warming or cooling??”Ah, the voice of sober second thought. Right. We don’t have prehistory weather reports. Can you point to a time before hundreds of heat records were broken this summer to find a time that was hotter ? But don’t be quiet. Give us more of your pearls of wisdom.. @ monica r As most scientists will mention THE ACCUMULATED EVIDENCE IS TOO MUCH TO IGNORE. Hundreds of heat records have been broken in a few weeks. {suitable for a generality, Dominic}Any further irrelevancies ? @ Bob S. “Don't worry”, What? Me worry?