A new study carried out by Zhengyao Lu, a researcher in Physical Geography at Lund University, and Benjamin Smith, director of research at the Hawkesbury Institute for the Environment at Western Sydney University. The scientists conclude that large-scale solar and wind farms could result in detrimental effects to the climate world-wide in which the results of their research was the subject of an article published in The Conversation.
The article states that the darker colors on solar panels attract and absorb more heat are much darker than the ground in and around the panels occupy. Consequently, the panels are not only 15% to 20% effective in converting sunlight into energy, but the remaining sunlight is returned to the surrounding area as heat.
In order for renewables to replace fossil fuels, the study states, the size of solar farms would have to be massive, covering thousands of miles. On this scale, the scientists say, solar farms would present an environmental danger on a local and global scale.
The article also cites a scientific manuscript was published three years ago revealing climate models demonstrated that installing a sufficient number of wind farms would not only double the precipitation in the Sahara desert, but determined that both solar and wind farms would drastically reduce the light reflected on the Earth’s surface. This, in turn would result in catastrophic effects on the Earth’s ecosystem. From The Conversation:
“The model revealed that when the size of the solar farm reaches 20% of the total area of the Sahara, it triggers a feedback loop. Heat emitted by the darker solar panels (compared to the highly reflective desert soil) creates a steep temperature difference between the land and the surrounding oceans that ultimately lowers surface air pressure and causes moist air to rise and condense into raindrops. With more monsoon rainfall, plants grow and the desert reflects less of the sun’s energy, since vegetation absorbs light better than sand and soil. With more plants present, more water is evaporated, creating a more humid environment that causes vegetation to spread.”
If the Sahara desert becomes a plush, green habitat, the ecological consequences would be disastrous. The result would be a deterioration of the Earth’s atmosphere along with heightened extreme weather events the likes of which have not been seen in a very long time and on a larger scale or even greater frequency.
The scientists also noted that efforts to reduce the Earth’s temperature could result in the opposite effect:
“Covering 20% of the Sahara with solar farms raises local temperatures in the desert by 1.5°C according to our model. At 50% coverage, the temperature increase is 2.5°C. This warming is eventually spread around the globe by atmosphere and ocean movement, raising the world’s average temperature by 0.16°C for 20% coverage, and 0.39°C for 50% coverage. The global temperature shift is not uniform though – the polar regions would warm more than the tropics, increasing sea ice loss in the Arctic. This could further accelerate warming, as melting sea ice exposes dark water which absorbs much more solar energy.”
The article’s authors finish stating renewable energy solutions may help society transition from fossil energy, but Earth system studies like ours underscore the importance of considering the numerous coupled responses of the atmosphere, oceans and land surface when examining their benefits and risks. In short, renewable energy’s risks or downsides far outweigh its benefits.
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