ASuch is our dependence on fossil fuels, and such is the volume of carbon dioxide already released into the atmosphere, that many experts agree that significant global warming is now inevitable. They believe that the best we can do is keep it at a reasonable level, and even that is going to take an extraordinary effort and a concerted international approach. But with emissions of carbon dioxide and other greenhouse gases still rising worldwide, some scientists are now beginning to explore alternatives. They are proposing scientific solutions that would manipulate the climate on a planetary scale: an approach known as geo-engineering.
BGeo-engineering has been described as a way of 'cooling the Earth'. Generally speaking, it falls into two categories: carbon dioxide removal, and solar radiation management. The former aims to remove greenhouse gases from the atmosphere, while the latter focuses on deflecting sunlight back into space before it can warm the planet. One of the most talked-about ideas is to inject sulfur dioxide particles into the upper atmosphere, simulating volcanic eruptions which naturally cool the planet. Another proposal suggests dispersing clouds with seawater to increase their reflectivity, or deploying giant reflective mirrors into orbit around the Earth.
CThe idea of employing geo-engineering is not new. In the 1960s, scientists in the Soviet Union suggested using reflective aerosols to melt arctic ice to open up shipping lanes. Later in the 1980s, American researchers proposed spreading tiny particles of aluminum oxide in the stratosphere. However, it was not until recent decades that the field began to be seen as a serious scientific response to global climate disruptions rather than science fiction.
DHowever, many scientists remain skeptical. Critics warn that geo-engineering is a high-risk gamble with unknown consequences. Injecting sulfur particles into the atmosphere, for example, could alter rainfall patterns, disrupt the Asian and African monsoons, and jeopardize food production for hundreds of millions of people. Furthermore, solar radiation management does nothing to address the problem of ocean acidification, which is caused directly by elevated levels of dissolved carbon dioxide.
EAnother profound concern is geopolitical. If a country or group decides to unilaterally initiate a geo-engineering project, whose hand will be on the global thermostat? In the absence of international treaties and governance frameworks, geo-engineering could provoke political disputes, retaliatory measures, or even international conflict if changes in one region's climate cause severe droughts or floods in another.
FFor these reasons, most climate scientists argue that geo-engineering should only ever be considered a temporary stopgap or backup plan. It must not be viewed as an alternative to reducing greenhouse gas emissions. The only lasting, sustainable solution to anthropogenic climate change remains the decarbonization of our global energy and industrial systems.
Reading Passage 3 has six paragraphs, A–F. Which paragraph contains the following information? Choose the correct letter A–F.
Complete the summary below. Choose NO MORE THAN TWO WORDS from the passage for each answer.
Geo-engineering consists broadly of two main categories. One aims to capture greenhouse gases, whereas the other focuses on .
Some proposals involve releasing particles into the stratosphere to mimic , or spraying clouds with to make them more reflective.
However, reflecting sunlight fails to solve , and most researchers view geo-engineering merely as a rather than a long-term solution.
Choose the correct letter, A, B, C, or D.
37. What is the main reason why scientists are exploring geo-engineering according to Paragraph A?
38. Soviet scientists in the 1960s suggested using reflective aerosols to
39. A major political threat mentioned in Paragraph E is that
40. The author concludes that the only true solution to climate change is