July 2023 was the world’s warmest month on record, according to the World Meteorological Organization. UN Secretary—General Antonio Guterres said in a speech that the planet is entering an “era of global boiling”. How to cool the planet has long been a troubling question for scientists. They are now turning to sun-blocking technology, which refers to reflecting sunlight back into space in order to keep down the temperature of the planet’s climate.
According to Euronews, a European television news network, one idea involves pumping sun-blocking particles (粒子) into the upper atmosphere. The particles will then stay in the air and redirect sunshine back upwards. It is like applying sunscreen on the outside of Earth. Researchers at Yale University, US, outlined a plan to use 125 high-flying planes to spread the particles at latitudes (纬度) of 60 degrees north and south. The particles will then travel toward the poles, which could possibly cool the temperature there by 2℃.
Another very promising technique is called “cloud brightening”, according to Chris Sacca, a US climate expert. This method involves sending sea salt particles into clouds above the sea, making them whiter and thus they reflect more sunlight back into space.
In June, the US government announced in a report that it was offering support for solar engineering research as a way to slow the rise of global temperatures. According to the report, the US government believes that the technology “offers the possibility of cooling the planet significantly in a few years”.
However, following the report, an open letter by more than 60 scientists called for caution and more research first. Kristen Rasmussen, a climate scientist at Colorado State University, US, has been studying how these sun-blocking methods will affect rainfall patterns. She said that apart from rainfall, ecosystems and even human communities would also be affected. “We need to be very cautious on this,” Rasmussen told Scientific American.
8. What do we know about sun-blocking particles?
A.They can catch and take in sunlight. | B.They function as a protective cover for Earth. |
C.They can release cool air into the atmosphere. | D.They are most effective when used at the poles. |
9. What is the US government’s attitude toward sun-blocking technology?
A.Favorable. | B.Pessimistic. | C.Objective. | D.Dismissive. |
10. What is Kristen Rasmussen’s main concern regarding sun-blocking methods?
A.Their potential impact on human health. | B.Their practicability in actual application. |
C.Their high cost and limited effectiveness. | D.Their far-reaching negative consequences. |
11. Which is the most suitable title for the text?
A.Cooling Our Planet | B.Era of Global Boiling |
C.Pumping Blocking Particles | D.The Technique of Cloud Brightening |