Cloze The changes in globally averaged temperature that have occurred at the Earth's surface over the past century are similar in size and timing to those 1 by models that take into account the combined influences of human factors and solar variability. To 2 the question of attribution requires the 3 of more powerful and complex methods, beyond the use of global averages alone. New studies have focused on 4 maps or patterns of temperature change in 5 and in models. Pattern analysis is the climatologically equivalent of the more comprehensive tests in the medical analogy mentioned 6 , and makes it possible to achieve more definitive 7 of observed climate changes to a particular cause or causes. The expected influence of human activities is thought to be much more complex than uniform warming over the entire surface of the Earth and over the whole 8 cycle. Patterns of change over space and time therefore provide a more powerful 9 technique. The basic idea 10 pattern-based approaches is that different 11 causes of climate change have different characteristic patterns of climate response or fingerprints. Attribution studies seek to 12 a fingerprint match between the patterns of climate change 13 by models and those actually observed. The most recent assessment of the science suggests that human activities have led to a discernible 14 on global climate and that these activities will have and increasing influence on future climate. The burning of coal, oil and natural gas, as well as various agricultural and industrial practices, are 15 the composition of the atmosphere and contributing to climate change, These human activities have led to increased atmospheric 16 of a number of greenhouse gases, including carbon dioxide, methane and so on in the lower atmosphere. Human activities, such as the burning of fossil, have also increased the 17 of small particles in the atmosphere. These particles can change the 18 of energy that is absorbed and reflected by the atmosphere. They are also believed to modify the 19 of air and clouds, changing the amount of energy that they absorb and reflect. Intensive studies of the climatic effects of these particles began only recently and the overall 20 is uncertain. It is likely that the net effect of these small particles is to cool the climate and to partially offset the warming of increasing concentrations of greenhouse gases.
When we think about addiction to drugs or alcohol, we frequently focus on negative aspects, ignoring the pleasures that accompany drinking or drug-taking. 21 the essence of any serious addiction is a pursuit of pleasure, a search for a "high" that normal life does not 22 . It is only the inability to function 23 the addictive substance that is dismaying, the dependence of the organism upon a certain experience and a(n) 24 inability to function normally without it. Thus a person will take two or three 25 at the end of the day not merely for the pleasure drinking provides, but also because he "doesn't feel 26 " without them. 27 does not merely pursue a pleasurable experience and need to 28 it in order to function normally. He needs to repeat it again and again. Something about that particular experience makes life without it 29 complete. Other potentially pleasurable experiences axe no longer possible, 30 under the spell of the addictive experience, his life is peculiarly 31 . The addict craves an experience and yet he is never really satisfied. The organism may be 32 sated, but soon it begins to crave again. Finally a serious addiction is 33 a harmless pursuit of pleasure by its distinctly destructive elements. A heroin addict, for instance, leads a 34 life: his increasing need for heroin in increasing doses prevents him from Working, from maintaining relationships, from developing in human ways. 35 an alcoholic's life is narrowed and dehumanized by his dependence on alcohol.