1 . If all goes well, a balloon will soon rise from Space Center in Sweden. It will float high into the upper atmosphere, where nothing will happen, and then return to Earth. Nevertheless, a collection of environmental groups is trying to stop it.
The campaigners are against the flight because of what comes next. The balloon is a test flight for a research being run by the University of Harvard. The research aims to test an idea called SAI, in which fine dust is added into the upper atmosphere to boost the amount of sunlight reflected back into space. A future flight will release a small amount of calcium carbonate dust into the upper atmosphere, in order to help researchers learn more about solar geoengineering — an excellent but theoretical idea of deliberately adjusting the Earth's systems to prevent the bad effects of climate change.
Opponents worry about two things. The first is the moral issue. If solar geoengineering works, it could reduce pressure to deal with climate change at its source by cutting greenhouse-gas emissions. Furthermore, in order to keep temperatures low, the reflective particles (颗粒) would have to be topped up continuously. A sudden stop could result in very rapid wanning. Raymond Pierrehumbert, a physicist at the University of Oxford, says solar geoengineering is too risky even to research outside of computer simulations (模拟).
Not all environmentalists are opposed. The world is likely to miss the target, set in the Paris agreement, of keeping warming to 1.5℃."We're not well-served by not understanding what these technologies represent," says Steven Hamburg. Mr Hamburg favours small-scale geoengineering research. Other green organisations have also hesitantly approved of exploring the idea.
Exploration is likely to carry on in any case. Once a taboo, geoengineering is being taken increasingly seriously. A recent report on climate change suggested that SAI could help keep warming below 1.5℃ America has developed a research plan for solar geoengineering. Both China and India have launched research programmes of their own. Activists will continue to oppose experiments. But balloons will likely fly anyway.
1. How does solar geoengineering work?| A．Dust is put into the upper atmosphere to trap more heat. |
| B．Measures are taken intentionally to tackle the climate change. |
| C．Steps are taken deliberately to reduce greenhouse-gas emissions. |
| D．Dust is emptied into the atmosphere to reflect sunlight into Earth. |
| A．It is to be implemented on a large scale. |
| B．It has led to global warming against the original intention. |
| C．It is probably to miss the target of keeping warming to 1.5℃. |
| D．It may cause people to care little about greenhouse-gas emissions. |
| A．Should balloons, flight be banned? |
| B．Should solar geoengineering exploration go ahead? |
| C．How do balloons threaten the earth's climate? |
| D．How has solar geoengineering changed Earth? |
| A．Critical. | B．Positive. | C．Doubtful. | D．Frightened. |
