The continued rise in Earth’s average temperature is turning cities and urban centers into concrete jungles, and traditional cooling solutions like air conditioning and insulation are failing to keep pace with a changing climate.
If the world doesn’t reduce its reliance on fossil fuels, scientists state that the Earth’s average temperature could rise 1.5°C (2.7 °F) by 2050 and 2°C to 4°C (3.6°F to 7.2°F) by 2100. For years, scientists have been looking for effective responses to this emerging problem, but no concrete solution has come to the surface that could be both environmentally sustainable and efficient.
However, researchers have created a new type of ultra-white paint that could offer a low-cost solution to this spiraling problem of excess heat. This cooling technology can keep the paint at a lower temperature than its surroundings and could be more affordable to manufacture.
A warming planet
Maintaining the Earth’s temperature is critical for sustaining the planet’s flora, fauna, and human species. A considerable percentage of all life forms existing on the planet is dependent on a continuous supply of fresh water, which, unfortunately, is a direct casualty of climate change.
Whether it’s the crops we sow, the fruits we harvest, or the animals we depend on for our various needs, or which are essential for keeping the ecosystem balanced, fresh water is the source of nourishment for many. However, with the temperature rising unabated, extreme weather events driven by climate change are likely to increase pollution, erosion, and sediment in waterways.
On the other hand, the rising temperature is also taking a considerable toll on routine urban life. Buildings nowadays need more resources to keep cool, and cars need more fuel to keep the air-conditioning going to make travel bearable. All these activities, powered by fossil fuels, cost the environment dearly and only add to the current climate crisis.
Therefore, ingenious solutions offering sustainable and low-cost alternatives to existing cooling technologies have become extraordinarily urgent.
A cooling effect
One of the ways builders have attempted to reduce the increasing dependence on air-conditioning in buildings is through the use of insulation technologies. But many of these technologies still have an environmental cost in the form of either biodegradability or the toxic nature of elements included in the insulating materials.
But researchers could have developed a promising paint that might put all our worries to rest. The paint, according to the researchers, reflects 95.5 percent of the sunlight that strikes its surface into outer space while maintaining a below-ambient temperature, i.e., being at a temperature lower than its surroundings. Existing heat-rejecting paints, on the other hand, can only reflect 80 to 90 percent of the sunlight and cannot achieve temperatures below ambient.
In his findings, Dr. Xiulin Ruan, Professor of Mechanical Engineering at Purdue University, said the technology could have a wide variety of applications in residential and commercial structures, data centers, warehouses, food storage, automobile industry, outdoor electrical equipment, military infrastructures, and utility vehicles. Real-world tests conducted over two days revealed that the paint sample remained 10°C (50°F) cooler than the ambient temperature at night and at least 1.7°C (35.06°F) below the surroundings when the Sun was at its peak during the day.
The secret to the paint’s performance lies in the elements Ruan incorporated in its development. Instead of the standard titanium dioxide particles, Ruan used calcium carbonate fillers with high particle concentration and broad size distribution. Calcium carbonate exists naturally in great abundance and has a superior ability to reflect ultraviolet light, which gives the paint a cooling effect.
An ideal cover
Ruan has been extremely confident about the range of benefits the paint technology could provide. He reported that the cost of the radiative cooling paints could be “comparable to or even lower” than existing commercial white paints and could offer an estimated $21 saving a month for a hundred m2 apartment.
“This paint may even be used to combat climate change since it rejects sunlight and radiates heat into space,” says Ruan.
His optimism might not be misplaced. Keeping our living spaces cool is becoming an increasingly difficult task and one that is incurring heavy losses to the environment. We have forced the planet into a vicious cycle of heat, and breaking free will require creative thinking and conscious effort. For the time being, at least, the ultra-white paint could be the fastest way to help the planet keep the heat in check.