All Roads Paved with Asphalt Trap 90% of the Sun's Heat—That's a Problem

Concrete buildings, asphalt paved roads radiating accumulated heat throughout the night, and lack of trees contribute to the making of scorching cities. 

The color white. (Credit: Shutterstock)
The color white. (Credit: Shutterstock)


Heat will be a huge problem in the future. According to NASA, 2016 was the third year in a row to set a new record for global average surface temperatures. And 2016 report from the journal Climate Change concluded that "globally, the probability that any summer during the period 2061–2081 will be warmer than the hottest on record during 1920–2014, is 80%."

For cities the problem is even bigger. On top of the rising temperatures, the urban heat island effect results in an additional 1.8 to 5.4°F burden for urban dwellers during the day and up to 22°F in the evenings. Concrete buildings, asphalt paved roads radiating accumulated heat throughout the night, and lack of trees contribute to the making of scorching cities. Active measures will be needed to reduce the risk of heat-related health problems.

On a sunny summer afternoon, urban air can be 1-3°C (2-5°F) warmer than nearby rural air / Berkeley Lab

It is no surprise that LA is one of the first cities to take such measures. The urban heat island effect makes LA almost six degrees hotter than the surrounding desert, and the heat causes 60 to 70 deaths every summer. Mayor Eric Garcetti has an ambitious plan to reduce the city’s average temperature by 3 degrees Fahrenheit over the next 20 years.  

KCRW reports that the plan will employ several measures. One is planting 40,000 more trees in the next two years, with a potential for 1 million more for the whole city. Studies show that trees have many positive effects on a city - from reducing temperatures and pollution to improving the mental health of citizens. Another measure from the plan is installing heat-reflecting roofs on new houses (12,000 have already been installed), which reflect more light and keep houses cooler. 

The third measure is still in its trial phase, but is already spiking interest in municipalities around the world. It consists of covering the city streets with a special type of light-colored coating called CoolSeal, which makes them more reflective and reduces the amount of heat trapped by asphalt. Traditional asphalt absorbs up to 90% of the sun’s radiation and contributes to warming up the surrounding air not only during the day, but also at night.

The LA Street Services twitter account has been providing updates of streets being treated with the new coating and comparing the surface temperatures of the treated and untreated asphalt. The difference can come up to 15 degrees Fahrenheit.

Ambient temp on Jordan Av this afternoon is over 100F
Regular asphalt is 153F
Cool Seal is only 138F!@BobBlumenfield cc @LHansenLA pic.twitter.com/pstO5F4NvO

— Greg Spotts (@Spottnik) August 30, 2017

U.S. Navy controls inventions that claim to change "fabric of reality"

Inventions with revolutionary potential made by a mysterious aerospace engineer for the U.S. Navy come to light.

U.S. Navy ships

Credit: Getty Images
Surprising Science
  • U.S. Navy holds patents for enigmatic inventions by aerospace engineer Dr. Salvatore Pais.
  • Pais came up with technology that can "engineer" reality, devising an ultrafast craft, a fusion reactor, and more.
  • While mostly theoretical at this point, the inventions could transform energy, space, and military sectors.
Keep reading Show less

Autonomous killer robots may have already killed on the battlefield

A brief passage from a recent UN report describes what could be the first-known case of an autonomous weapon, powered by artificial intelligence, killing in the battlefield.

Kargu-2 drone

STM
Politics & Current Affairs
  • Autonomous weapons have been used in war for decades, but artificial intelligence is ushering in a new category of autonomous weapons.
  • These weapons are not only capable of moving autonomously but also identifying and attacking targets on their own without oversight from a human.
  • There's currently no clear international restrictions on the use of new autonomous weapons, but some nations are calling for preemptive bans.
Keep reading Show less

Is healthy sugar possible — and would you eat it?

Israeli food-tech company DouxMatok (Hebrew for "double sweet") has created a sugary product that uses 40 percent less actual sugar yet still tastes sweet.

Photo: pixel-shot / Adobe Stock
Surprising Science
  • Consumers are fed a lot of nonsense about sugar and fad diets.
  • Our bodies must consume sugar; the question is how much and in what form.
  • Companies are trying to develop healthier sugars to combat our "sugar addiction."
Keep reading Show less
Quantcast