英语资料——英译汉.doc

第六单元
Common questions about climate change
This document answers some of the most commonly asked questions about climate change, including whether the Earth has warmed, which human activities are contributing to climate change, what further climatic changes are expected to occur, and what effects these changes may have on humans and the environment. First, however, several issues are clarified: what the Earth's climate is, how climate differs from weather, and what processes influence climate.
本文档的答案对气候变化最常问的一些问题,包括是否地球变暖,人类活动是导致气候变化,气候变化预计将进一步发生什么,什么影响这些变化可能对人类和环境。首先,然而,澄清几个问题:什么是地球的气候,气候与天气如何,过程影响气候。
Climate is the average weather, including seasonal extremes and variations, either locally, regionally, or across the globe. In any one location, weather can change very rapidly from day to day and from year to year, even within an unchanging climate. These changes involve shifts in, for example, temperatures, precipitation, winds, and clouds. In contrast to weather, climate is generally influenced by slow changes in features like the ocean, the land, the orbit of the Earth about the sun, and the energy output of the sun.
极端气候平均的天气,包括季节性变化,无论在本地,区域或全球。在任何一个位置,天气可以改变非常迅速从日复一日,年复一年,甚至在一个不变的气候。这些变化涉及的变化,例如,温度、降水、风和云。与天气、气候通常是缓慢变化的影响特性,如海洋,土地,地球对太阳的轨道,太阳的能量输出。
Fundamentally, climate is controlled by the long-term balance of energy of the Earth and its atmosphere. Incoming radiation from the sun, mainly in the form of visible light, is absorbed at the Earth's surface and in the atmosphere above. On average, absorbed radiation is balanced by the amount of energy returned to space in the form of infrared "heat" radiation. Greenhouse gases such as water vapor and carbon dioxide, as well as clouds and small particles (called aerosols), trap some heat in the lower part of the Earth's atmosphere. This is called the greenhouse effect. If there were no natural greenhouse effect, the average surface temperature would be about 34°C (61°F) colder than it is today.
从根本上说,气候由长期控制地球及其大气层的能量平衡。来自太阳的入射辐射,主要以可见光的形式,吸收地球表面和大气中。平均而言,吸收辐射平衡的能量回到空间形式的红外辐射“热”。水蒸气和二氧化碳等温室气体以及云和小颗粒(称为气溶胶),陷阱的一些热量较低的地球大气层的一部分。这就是所谓的温室效应。如果没有自然温室效应、表面平均温度约为34°C(61°F)比今天更冷。
Winds and ocean currents redistribute heat over the surface of the Earth. The evaporation of surface water and its subsequent condensation and precipitation in the atmosphere redistribute heat between the Earth's surface and the atmosphere, and between different parts of the atmosphere.
风和洋流分配在地球表面热量。表面水的蒸发和随后的凝结和大气降水分配加热地球表面和大气之间,以及不同部分之间的气氛

Figure 1.1
Schematic view of components of the global climate system, some of their processes and interactions, and some aspects that can cause climate change.
图解视图组件的全球气候系统,他们的一些流程和交互,有些方面会引起气候变化。
Natural events cause changes in climate. For example, large volcanic eruptions put tiny particles in the atmosphere that block sunlight, resulting in a surface cooling of a few years' duration. Variations in ocean currents change the distribution of heat and precipitation. El Niño events (periodic warming of the central and eastern tropical Pacific Ocean) typically last one to two years and change weather patterns around the world, causing heavy rains in some places and droughts in others. Over longer time spans, tens or hundreds of thousands of years, natural changes in the geographical distribution of energy received from the sun and the amounts of greenhouse gases and dust in the atmosphere have caused the climate to shift from ice ages to relatively warmer periods, such as the one we are currently experiencing.
自然事件导致气候变化。例如,大型火山喷发把大气中的微小颗粒,阻挡阳光,导致表面冷却几年的持续时间。洋流的变化改变热量和降水的分布。厄尔尼诺事件(周期性变暖的中部和东部热带太平洋)通常持续一到两年,改变全球气候模式,造成一些地方的暴雨和干旱。在时间跨度,数万或数十万年,自然地理分布的变化能源来自太阳和大气中的温室气体和尘埃的数量造成的气候从冰河时代转向相对温暖的时期,比如我们目前经历的人。
Human activities can also change the climate. The atmospheric amounts of many greenhouse gases are increasing, especially that of carbon dioxide, which has increased by 30% over the last 200 years, primarily as a result of changes in land use (e.g., deforestation) and of burning coal, oil, and natural gas (e.g., in automobiles, industry, and electricity generation). If current trends in emissions were to continue, the amount of carbon dioxide in the atmosphere would double during the twenty-first century, with further increases thereafter. The amounts of several other greenhouse gases would increase substantially as well.
人类的活动也可以改变气候。大气的许多温室气体增加,特别是二氧化碳,在过去的200年里增加了30%,主要是由于土地利用变化(如、森林砍伐)和燃烧煤炭,石油和天然气(如。在汽车、工业和发电)。在排放如果当前的趋势继续,大气中二氧化碳的量将翻倍在二十一世纪,之后进一步增加。其他温室气体的数量将大幅增加。
The accumulation of greenhouse gases in the atmosphere due to human activities will change the climate by enhancing the natural greenhouse effect, leading to an increase in the Earth's average surface temperature. This warming may be partially offset in certain regions where air pollution leads to high concentrations of small particles in the atmosphere that block sunlight.
大气中温室气体的积累,由于人类活动将改变气候提高自然温室效应,导致地球的平均表面温度的增加。这种变暖可能部分抵消在某些地区空气污染会导致大气中高浓度的小颗粒,阻挡阳光。
The current best estimate of the expected rise of globally averaged surface temperature relative to 1990 is 1 to 3.5°C (about 2 to 6°F) by the year 2100, with continued increases thereafter. Because most greenhouse gases remain in the atmosphere for a long period of time, even if emissions from human activities were to stop immediately, effects of accumulated past emissions would persist for centuries.
当前的最佳估计预期的全球平均地表温度上升相对于1990 1 - 3.5°C(约2 - 6°F)到2100年,此后持续增长。因为大多数温室气体在大气中停留很长一段时间,即使人类活动排放立即停止,过去排放将持续几个世纪以来积累的效果。
The Intergovernmental Panel on Climate Change (IPCC), cosponsored by the United Nations Environment Programme and the World Meteorological Organization and made up of over 2000 scientific and technical experts from around the world, published its First Assessment Report in 1990 and its Second Assessment Report in 1996. The Second report contains over 10,000 references and is over 2000 pages in length. Although our understanding of some details of climate change is still evolving, the IPCC report is the most comprehensive and scientifically authoritative account of our understanding of climate change, the potential impacts on humans and the natural environment, the technology currently available to reduce human influences on climate, and the socio-economic implications of possible measures to mitigate these changes. The document that follows has been written and reviewed by scientists who participated in the IPCC process, and it attempts to answer some of the most commonly asked questions about these issues, based upon information contained in the IPCC reports. A list of the scientists who prepared this document is provided inside the front cover.
政府间气候变化专门委员会(IPCC),儿童联合国环境规划署和世界气象组织,由来自世界各地的超过2000篇的科学和技术专家,公布了1990年首次评估报告,在1996年第二次评估报告。第二个报告包含超过10000引用和超过2000页的长度。虽然我们了解气候变化的一些细节仍在不断发展之中,IPCC的报告是最全面、科学权威的我们对气候变化的理解,可能对人类和自然环境的影响,当前可用的技术来减少人类对气候的影响,以及可能的措施,减轻这些变化的社会经济影响。接下来的文档编写和审查了科学家参与IPCC过程,并试图回答一些最常问的问题这些问题,基于IPCC报告中包含的信息。科学家们准备这个文档的列表在封面提供。

Are human activities contributing to climate change
A comprehensive assessment by the IPCC of the scientific evidence suggests that human activities are contributing to climate change, and that there has been a discernible human influence on global climate.
IPCC综合评价的科学证据表明,人类活动是导致气候变化,而且有明显的人类对全球气候的影响。
Climate changes caused by human activities, most importantly the burning of fossil fuels (coal, oil, and natural gas) and deforestation, are superimposed on, and to some extent masked by, natural climate fluctuations. Natural changes in climate result from interactions such as those between the atmosphere and ocean, referred to as internal factors, and from external causes, such as variations in the sun's energy output and in the amount of material injected into the upper atmosphere by explosive volcanic eruptions.
人类活动导致的气候变化,最重要的是燃烧化石燃料(煤、石油和天然气)和森林砍伐,叠加上,而且在某种程度上掩盖了,自然气候波动。自然气候的变化导致大气和海洋之间的互动等,称为内部因素,并从外部原因,如太阳能量输出的变化量和材料注入到上层大气的爆炸性火山喷发。
Studies that aim to identify human influences on climate attempt to separate a human-caused climate-change factor (the signal) from the background noise of natural climate variability. Such investigations usually consist of two parts: detection of an unusual change, and attribution of all or part of that change to a particular cause or causes.
研究旨在确定人类影响气候试图单独一个人为气候变化因素(信号)自然气候变化的背景噪音。这样的调查通常由两部分组成:一个不寻常的变化,检测和归因的全部或部分,改变一个特定的原因或原因。
The concepts of detection and attribution may be understood in terms of a simple medical analogy. Measurement of a body temperature of 40°C (104°F) detects the presence of some abnormal condition or symptom, but does not in itself give the cause of the symptom. To attribute the symptom to an underlying cause often requires additional and more complex tests, such as chemical analyses of blood and urine, or even x-rays and CAT scans.
检测和归因的概念可以理解的一个简单的医学类比。测量体温的40°C(104°F)检测存在一些变态或症状,但本身不给症状的原因。症状归因于一个根本原因通常需要额外的和更复杂的测试,如化学分析血液和尿液,甚至x射线和CAT扫描。
 Early work on climate-change detection examined changes in the globally averaged surface temperature of the Earth over the last century. Most studies of this type concluded that the observed increase of roughly 0.5°C (about 1°F) was larger than would be expected as a result of natural climate variability alone.

早期从事气候变化检测研究地球的全球平均地表温度的变化在过去的世纪。这种类型的大多数研究得出结论:观察增加约0.5°C(约1°F)大于自然气候变化的预期结果。

 Observed globally averaged temperature changes have also been analyzed away from the Earth's surface. The observations used come from conventional weather observing instruments (radiosondes) and from satellites. As expected, because of the different factors affecting the variability of and persistence of temperatures at different altitudes, there are noticeable differences between short-term trends at the surface and those at higher altitudes. The record of temperatures away from the Earth's surface, which spans only the past 40 years compared with the much longer surface record, is too short for globally averaged values to provide any definitive information about the extent of human influences.

观察到的全球平均气温变化也远离地球表面分析。观察使用来自常规气象观测仪器(radiosondes)和卫星。正如所料,由于不同影响因素的可变性和持久性的温度在不同的海拔,短期趋势,表面有明显的差异,在高海拔地区。离地球表面温度的记录,这只跨越过去的40年里与更长的表面记录相比,太短了,全球平均价值提供任何明确的信息对人类影响的程度。

The further step of attributing some part of observed temperature changes to human influences makes use of climate models, which have been employed to estimate the climatic effects of a range of human-induced and natural factors. The human factors include recent changes in the atmospheric concentrations of both greenhouse gases and sulfate particles (called "aerosols"). The natural factors considered include solar variability, the effects of volcanic eruptions, and internal variability of the climate system resulting from interactions among its individual components.

进一步,将部分观察温度变化对人类的影响利用气候模型,已被用来估计气候各种人为和自然因素的影响。人为因素包括最近大气的温室气体浓度的变化和硫酸盐颗粒(称为“气溶胶”)。考虑自然因素包括太阳能可变性,火山爆发的影响,和内部气候系统的变化导致其各个组件之间的交互。

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 predicted by models that take into account the combined influences of human factors and solar variability. 

全球平均温度的变化发生在地球表面的在过去的一个世纪是相似的大小和时间预测模型,考虑人为因素的综合影响和太阳能可变性。

To probe the question of attribution requires the application of more powerful and complex methods, beyond the use of global averages alone. New studies have focused on comparing maps or patterns of temperature change in observations and in models. Pattern analysis is the climatological equivalent of the more comprehensive tests in the medical analogy mentioned previously, and makes it possible to achieve more definitive attribution of observed climate changes to a particular cause or causes.

调查的问题归因需要更强大的应用和复杂的方法,除了使用单独的全球平均水平。新的研究主要集中在比较地图或温度变化观测和模型的模式。模式分析气候相当于在医学类比前面所提到的,更全面的测试,可以实现更多的归因观察到的气候变化的特殊原因或原因。

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 seasonal cycle. Patterns of change over space and time therefore provide a more powerful analysis technique. The basic idea underlying pattern-based approaches is that different potential causes of climate change have different characteristic patterns of climate response or fingerprints. Attribution studies seek to obtain a fingerprint match between the patterns of climate change predicted by models and those actually observed.
预期的影响,人类活动被认为是更复杂的比统一的变暖对整个地球表面并在整个季节周期。因此随时间和空间变化的模式提供了一个更强大的分析技术。基于模式的方法背后的基本思想是,不同的气候变化的潜在原因有不同的气候响应或指纹的特征模式。归因研究寻求获得指纹匹配的模式模型和那些实际上观察到的气候变化预测。

Comparisons between observed patterns of temperature change and those predicted by models have now been made at the Earth's surface and in vertical sections through the atmosphere (Figure 3.1). Model predictions show increasing agreement with changes observed over the past 30-50 years. The closest agreement occurs when the combined effects of greenhouse gases and sulfate aerosol particles are considered. Statistical analyses have shown that these correspondences are highly unlikely to have occurred by chance.

对比观察到的温度变化模式和预测的模型现在已经在地球表面和在垂直部分通过大气层(图3.1)。模型预测显示增加协议变化观察过去30 - 50年。最近的协议时发生硫酸温室气体和气溶胶粒子的组合效应。统计分析表明,这些通讯是极不可能发生的机会。

The agreements between the patterns of change predicted by models and those actually observed are due to similarities at large spatial scales, such as contrasts between the temperature changes in the northern and southern hemispheres or between different levels of the atmosphere. It is at these large scales that we have most confidence in model performance. More importantly, many of the results of these studies agree with our physical understanding of the climate system, and do not depend solely on numerical models or statistical techniques.

变化的模式预测模型之间的协议和那些实际上是由于观察到相似的空间尺度,如温度变化之间的对比在北半球和南半球或不同级别之间的气氛。在这些大的尺度上,我们有最信任模型的性能。更重要的是,许多这些研究的结果同意我们的身体对气候系统的理解,并不能仅仅依靠数值模型或统计技术。

There are still uncertainties in these detection and attribution studies. These are due primarily to our imperfect knowledge of the true climate-change signal due to human activities, to our incomplete understanding of the background noise of natural climatic variability against which this signal must be detected, and to inadequacies in the observational record. Such uncertainties make it difficult to determine the exact size of the human contribution to climate change. Nevertheless, the most recent assessment of the science suggests that human activities have led to a discernible influence on global climate and that these activities will have an increasing influence on future climate.

在这些检测仍存在不确定性和归因研究。这些主要是由于我们的不完美的知识真正的气候变化信号由于人类活动,我们不完全理解的自然气候变化的背景噪音,这个信号必须检测,并观察记录中的不足。这种不确定性使它很难确定具体的人类对气候变化的贡献的大小。然而,最近的科学评估表明,人类活动导致了对全球气候有明显的影响,这些活动将会越来越对未来气候的影响。
What human activities contribute to climate change?
The burning of coal, oil, and natural gas, as well as deforestation and various agricultural and industrial practices, are altering the composition o