Nav: Home

Reflective surfaces alleviate heatwaves

January 30, 2018

Climate change will make heatwaves more common, and continental areas and urban regions that become significantly warmer in summer will be particularly affected. Together with colleagues from Australia and the US, ETH researchers have now detailed a practical approach that combines clever land use and urban radiation management to help cool extreme summer temperatures locally. Their study has just been published in the journal Nature Geoscience.

Greater reflection breaks up temperature peaks

The scientists' approach is based on the different reflection properties of ground surfaces. For instance fields left unploughed after harvest reflect significantly more sunlight that ploughed ones (as ETH News reported). Similarly, crop selection for brighter species and the implementation of reflective material on roofs, streets and other urban infrastructure could increase the surface reflectivity and cool local climate .

"These measures could help to lower extreme temperatures in agricultural regions and densely populated areas by up two to three degrees Celsius," says Sonia Seneviratne, ETH Professor of Land-Climate Dynamics and first author of the study. In this context, the hotter it becomes, the stronger the effect. The cooling effect only works in the short term, however, and is local or regional rather than global - but this regional contribution is still very important, emphasises Seneviratne.

Suitable for Europe and the US, less so for Asia

The researchers obtained their findings using simulations. They used these simulations to examine how radiation-optimised agricultural surfaces and metropolitan areas in North America, Europe and Asia affect average temperatures, extreme temperatures and precipitation.

The models showed that the measures had a negligible effect on average temperatures and only slightly altered precipitation - except in Asia - but significantly reduced extreme temperatures. In Asia, India and China, the levels of the crucial monsoon rains also decreased in the simulations, suggesting that the selected approach is unsuitable for these countries.

Alternatives for climate and geoengineering

The measures that could be used for this type of radiation management already exist and have largely been tested, although they have only been applied on a small scale or for other purposes. In contrast, it is doubtful whether other climate techniques currently discussed as "geoengineering" actually work to adjust or avoid climate change. Interventions such as spraying sulphate aerosols into the atmosphere, fertilising the oceans with iron or placing huge mirrors in space are likely to have unpredictable effects on the Earth's climate and ecosystems, potentially making the situation even worse.

"Regional radiation management can be effective, but even here, we have to consider any potential effects on food production, biodiversity, CO2 absorption, recreation areas and much more before we can actually implement it," says Seneviratne. And she points out: "Even this climate technique is no silver bullet; it's just one potential tool among several others in the battle against climate change."
-end-
Reference

Seneviratne SI, Phipps SJ, Pitman AJ, Hirsch AL, Davin EL, Donat MG, Hirschi M, Lenton A, Wilhelm M, Kravitz B: Land radiative management as contributor to regional-scale climate adaptation and mitigation. Nature Geoscience, 29 January 2017, doi: 10.1038/s41561-017-0057-5

ETH Zurich

Related Climate Change Articles:

A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.
Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).
Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.
Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.
Could climate change cause infertility?
A number of plant and animal species could find it increasingly difficult to reproduce if climate change worsens and global temperatures become more extreme -- a stark warning highlighted by new scientific research.
Predicting climate change
Thomas Crowther, ETH Zurich identifies long-disappeared forests available for restoration across the world.
Historical climate important for soil responses to future climate change
Researchers at Lund University in Sweden, in collaboration with colleagues from the University of Amsterdam, examined how 18 years of drought affect the billions of vital bacteria that are hidden in the soil beneath our feet.
Can forests save us from climate change?
Additional climate benefits through sustainable forest management will be modest and local rather than global.
From crystals to climate: 'Gold standard' timeline links flood basalts to climate change
Princeton geologists used tiny zircon crystals found in volcanic ash to rewrite the timeline for the eruptions of the Columbia River flood basalts, a series of massive lava flows that coincided with an ancient global warming period 16 million years ago.
Think pink for a better view of climate change
A new study says pink noise may be the key to separating out natural climate variability from climate change that is influenced by human activity.
More Climate Change News and Climate Change Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

In & Out Of Love
We think of love as a mysterious, unknowable force. Something that happens to us. But what if we could control it? This hour, TED speakers on whether we can decide to fall in — and out of — love. Guests include writer Mandy Len Catron, biological anthropologist Helen Fisher, musician Dessa, One Love CEO Katie Hood, and psychologist Guy Winch.
Now Playing: Science for the People

#543 Give a Nerd a Gift
Yup, you guessed it... it's Science for the People's annual holiday episode that helps you figure out what sciency books and gifts to get that special nerd on your list. Or maybe you're looking to build up your reading list for the holiday break and a geeky Christmas sweater to wear to an upcoming party. Returning are pop-science power-readers John Dupuis and Joanne Manaster to dish on the best science books they read this past year. And Rachelle Saunders and Bethany Brookshire squee in delight over some truly delightful science-themed non-book objects for those whose bookshelves are already full. Since...
Now Playing: Radiolab

An Announcement from Radiolab