‎ ‎ ‎ ‎ The effects of climate change are coming into sharper focus: because of increased global temperatures, sea levels are rising, plants are blooming earlier in the spring, and water supplies are declining. That the global climate may reach a dangerous turning point, threatening food supplies, has become a real possibility.

 ‎ ‎ ‎ ‎ The best way to reduce this danger is to cut emissions of carbon dioxide and other greenhouse gases. But success requires that all major greenhouse-gas- emitting countries, with their divergent, often conflicting interests, cooperate for several decades in a sustained effort to develop and deploy new technology that produces much lower emissions. Incentives to drop out of this effort, thereby avoiding the high cost of emission controls, will be strong. A more feasible solution is for governments to promote an international cooperative study and the eventual implementation of geoengineering the deliberate manipulation of Earth's atmosphere to counteract the warming effect of greenhouse-gas emissions.

 ‎ ‎ ‎ ‎ This must be an international effort, because unilateral geoengineering could have detrimental consequences. The discovery of the cooling effects of volcanic emissions has suggested a means of geoengineering that is feasible for any reasonably technologically advanced nation and relatively inexpensive. For as little as a few billion dollars, a nation could emulate these volcanic effects by deliberately putting reflective particles into the upper atmosphere. Without proactive international cooperation, a country may conclude that global warming has become so harmful to its interests that it should unilaterally engage in geoengineering without considering the effects on other countries, effects that could be catastrophic.

 ‎ ‎ ‎ ‎ Thus, governments must support an international program of scientific research that would help on three fronts: (1) transform discussion about geoengineering into focused assessment of concrete risks; (2) secure funding and political cover for essential but controversial experiments that are conducted by the world's leading scientists and are evaluated in a fully transparent fashion; (3) craft norms for the testing and possible deployment of geoengineering technologies. Scientists could be influential in creating these norms, just as nuclear scientists framed options on nuclear testing and influenced pivotal government decisions during the Cold War.

1. The passage indicates that, at the time the passage was written, discussion of geoengineering tended

A. to take for granted that international efforts will eventually successfully reduce the amount of greenhouse gases that are emitted

B. to be uniformed by current science

C. to disregard questions of what norms should govern the testing and possible deployment of geonengineering technologies

D. to be unduly influenced by prejudice against geoengineering

E. not to involve a focused assessment of the concrete risks of geoengineering



2. Which of the following most accurately states the main point of the passage?

A. The discovery of the cooling effects of volcanic emissions has led to the threat of potentially catastrophic unilateral geoengineering on the part of a reasonably technologically advanced nation

B. To confront the threat of global warming and helo forestall potential risky unilateral action, governements should promote an international study of geoengineering.

C. The best way to reduce the danger of climate change is through geoengineering, but without further study its effects will not be well understood

D. A research program conducted by the world's leading scientists could effectively establish norms for the testing and deployment of geoengineering technologies.

E. The effects of global warming have come into sharper focus, resulting in the need to develop new means of cutting the emissions of greenhouse gases.



3. The passage most strongly implies which of the follwing?

A. The easiest and most cost-effective means of geoengineering is likely to be launching reflective materials into the upper atmosphere

B. Cooling the planet through geoengineering will repair the damage caused by climate change

C. Without creating an international program of scientific research into geoengineering, any field trials of geoengineering efforts will likely lead to widespread protests

D. Implementation of geoengineering will ultimaely be necessary to counteract the effects of climate change.

E. Norms governing nuclear testing during Cold War were directly influenced by research conducts by nuclear scientists. 



4. Which of the following most accurately describes the structure of the passage as a whole?

A. A response to the problem mentioned in the first paragraph is presented in the second paragraph and is supported and fleshed out in later paragraphs.

B. A claim made in the first paragraph is explained in the second and third paragraphs and justified with three points in the final parargraph.

C. A problem is posed in the first paragraph, an argument supporting the claim that the problem is serious is presented in the second and third paragraphs, and a solution is sketched in the final paragraph.

D. A problem is posed in the paragraph, one solution is suggested in the second paragraph, a potential problem with the solution is sketched in the third paragraph, and a different solution is offered and argued for with three points in the final paragraph.

E. A general view is supported in the first paragraph, criticized in the second and third paragraphs, with poterntial means of defleciting these criticisms offered in the final paragraph.­