18.50 全球升温 -- -- 高级
章节大纲
-
Could the whole planet look like this?
::整个星球都像这样吗?Dead Vlei in Namibia, shown above, doesn't seem to get much rain. Could the whole planet look like this? Probably not any time soon. But if global climate change continues, 10,000 years from now, what could the consequences be?
::纳米比亚的Vlei死神(如上所示)似乎没有大雨。整个地球会这样吗?也许不会很快。但如果全球气候变化继续下去,在一万年后的一万年后,后果会是什么?Global Warming
::全球变暖Global warming , which is also known as global climate change, refers to the recent increase in the Earth’s average near-surface and ocean temperatures ( Figure ). During the past 100 years, surface air temperatures have risen 0.74 ± 0.18 °C (1.33 ± 0.32 °F). Multiple sources agree that the two warmest years since the introduction of reliable instrumentation in the 1800s were 1998 and 2005.
::全球升温也称为全球气候变化,它指的是地球平均近地和海洋温度最近上升(图 ) 。 在过去的100年里,地表空气温度上升了0.74 °C + 0.18 °C ( 1.33 + 0.32 °F ) 。 多个来源都认为,自1800年代引入可靠仪器以来的两年最暖的年份是1998年和2005年。Global warming refers to the increase in Earth’s average near-surface temperatures over the past 100 years. “Anomalies” measure deviation from 1961-1990 averages.
::全球变暖是指过去100年中地球平均近地表温度的上升。 “异常”衡量标准偏离了1961-1990年的平均数。This recent increase contrasts with relatively stable temperatures shown by scientific data for the previous two millennia. Multiple sets of temperature data inferred from tree rings, coral growth, and ice core samples are compiled in Figure . Warmly debated exceptions to the stability include a warm period during the Middle Ages and a “Little Ice Age,” attributed to decreased solar activity and increased volcanism.
::最近这一增长与前两千年的科学数据显示的相对稳定的气温形成对比。 图中汇编了从树环、珊瑚生长和冰芯样本中推断出来的多套温度数据。 激烈辩论的稳定性例外包括中世纪的温暖时期和“小冰时代 ” , 其原因是太阳活动减少和火山活动增加。Global temperatures compiled from tree ring, coral growth, ice core analysis, and historical records, show relative stability over the last 2,000 years before about 1850, interrupted by a debatable Medieval warming and a more recent cooling termed the “Little Ice Age.” Colored lines indicate different published data sources.
::从树环、珊瑚生长、冰芯分析和历史记录中汇编的全球温度显示,在大约1850年前的2000年中,由于中世纪变暖和最近称为“小冰时代”的冷却而中断,全球气温相对稳定。 彩色线显示了不同的公开数据来源。According to paleoclimatologists, on a scale of millions of years Earth’s temperatures have varied almost regularly (over time intervals of roughly 140 million years) from those which support global tropics to continental glaciations ( Figure ). Scientists estimate the global average temperature difference between an entirely glaciated Earth and an ice-free Earth to be 10 o C.
::古生物学家认为,在数百万年的尺度上,地球的温度几乎经常(时间间隔约为1.4亿年 ) , 从支撑全球热带的温度到大陆冰川(图 ) 。 科学家估计,完全冰川化的地球和无冰的地球之间的全球平均气温差异是10°C。Paleoclimatological measures of global temperatures show dramatic fluctuations in temperature. Graphs should be read from right (past) to left (present). Ice core data for temperature is recorded in oxygen isotope units rather than o C.
::全球温度的显性气候测量显示温度急剧波动,图表应从右(过去)到左(现在)读取,温度的冰核心数据记录在氧同位素单位中,而不是有机碳。The causes of Ice Ages are not completely understood, but greenhouse gases , especially CO 2 levels, often correlate with temperature changes ( Figure ). Rapid buildup of greenhouse gases in the Jurassic Period 180 million years ago correlates with a rise in temperature of 5 o C (9 o F). Similar changes have been hypothesized as causes for the dramatic Permian Extinction 250 million years ago and the Paleocene-Eocene Thermal Maximum (one of the most rapid and extreme global warming events recorded in geologic history) 55 million years ago. Paleoclimatologist William Ruddiman proposes that human activities began to affect global CO 2 levels as long ago as 8,000 years, when and deforestation began. Ruddiman argues that without this early contribution to greenhouse gases, cycles indicate the Earth would already have entered another Ice Age.
::冰河时代的原因并不完全被理解,但温室气体,特别是二氧化碳水平,往往与温度变化相关(图 ) 。 在1.8亿年前的侏罗纪周期中,温室气体的迅速积累与5°C(9°F)的温度上升相关。 类似的变化被假设为2.5亿年前的戏剧性的 Permian Extinction 2.5亿年前和5500万年前的Paleone-Eenne热峰(地质史上记录的最迅速和极端的全球升温事件之一 ) , 5500万年前的Paleoclimat学家William Ruddiman提出人类活动早在8000年前就开始影响全球二氧化碳水平,当时是8000年,并且开始砍伐森林。 Rudiman认为,如果没有对温室气体的早期贡献,周期就表明地球已经进入了另一个冰河时代。Over the past 450,000 years, temperature changes (blue) correlate closely with changes in atmospheric CO 2 (green) and dust levels (red).
::在过去45万年中,温度变化(蓝色)与大气二氧化碳(绿色)和尘埃水平(红色)的变化密切相关。Others dispute Ruddiman’s “overdue-glaciation” theory , but most scientists today agree that recent global warming since 1850 is caused by an unprecedented rise in atmospheric CO 2 ( Figure ) which resulted from human activities – primarily burning of fossil fuels , but also continuing deforestation and changes in land use. Fossil fuels burn in the same way your burn glucose to make ATP : a product of both reactions is CO 2 . Deforestation and other land use changes contributes to the CO 2 levels from the opposite direction – a decrease in , which would have removed CO 2 from the atmosphere . Slash-and-burn destruction of forests combines the worst of both worlds; burning adds CO 2 to the atmosphere, and the loss of layers of vegetation decreases CO 2 use.
::另一些人则质疑鲁迪曼的“逾期的冰川”理论,但今天大多数科学家都认为,1850年以来的全球变暖是人类活动造成的大气二氧化碳(Figure ) ( Figure ) , 主要是化石燃料燃烧,但也持续砍伐森林和土地使用变化造成的大气二氧化碳(Figure ) 的空前上升造成的。 化石燃料同样燃烧燃烧你的燃烧葡萄糖,从而形成ATP:这两种反应的产物是CO2 。 砍伐森林和其他土地使用变化导致二氧化碳水平从相反方向上升 — — 下降,这本可以将二氧化碳从大气中清除出来。 森林的冲击和燃烧破坏结合了两个世界的最严重现象;燃烧增加了大气中的二氧化碳,而植被层的流失也减少了二氧化碳的使用。Two additional greenhouse gases having anthropogenic (human activity) sources are methane (CH 4 ) and nitrous oxide (NO). Agriculture adds both of these to the atmosphere; cattle production is responsible for much of the methane, a powerful greenhouse gas. Land use changes, waste processing, and fossil fuel production, which we’ve already implicated in CO 2 increases, are other anthropogenic sources (human-caused). A last but important contributing factor is secondary to these primary causes; triggers of “runaway greenhouse effects” will be discussed below.
::人为(人类活动)来源的另外两种温室气体是甲烷(CH4)和一氧化二氮(NO)。 农业将这两种气体都添加到大气中;养牛生产是大部分甲烷(一种强大的温室气体)的原因。 土地使用的变化、废物处理和化石燃料生产(我们已经将之与二氧化碳的增加联系在一起)是其他人为来源(人为造成的 ) 。 最后一个但重要的促成因素是这些主要原因的次要因素;下面将讨论“失控温室效应”的触发因素。Since the Industrial Revolution began, the burning of fossil fuels has dramatically increased atmospheric concentrations of CO 2 to levels unprecedented in the last 400 thousand years. The graph on the right integrates recent measurements with paleoclimatologic data.
::自工业革命开始以来,化石燃料的燃烧使大气中二氧化碳的浓度急剧上升,达到40万年来前所未有的水平。 右边的图表将最近的测量数据与古生物学数据结合起来。Although the causal connections between fossil fuel combustion, deforestation, greenhouse gases, the , and global warming have been strongly debated in the past, the majority of the world’s scientific organizations now support these relationships, and many use the term “consensus.” (See “Scientific Opinion about Climate Change” in Further Reading.) The awarding of the Nobel Peace Prize to the organization which focuses most directly on climate change, the IPCC, highlights this consensus. Alternative hypotheses include variation in solar activity; several references are included in Further Reading. The IPCC projects future temperature increases ranging from 1.1 °C to 6.4 °C (2.0 °F to 11.5 °F) between 1990 and 2100. Predictions from multiple models which incorporate connections between greenhouse emissions and global warming are summarized in Figure ; all show significant rises in temperature by 2100.
::虽然过去曾对化石燃料燃烧、毁林、温室气体、温室气体、全球变暖之间的因果关系进行过激烈辩论,但世界大多数科学组织现在都支持这些关系,许多组织使用“共识”一词(见“关于气候变化的科学意见”,进一步阅读)。 诺贝尔和平奖授予最直接关注气候变化的组织,即气专委,突出了这一共识。 替代假设包括太阳活动的变化;在《进一步阅读》中包括了几个参考。 气专委预测1990年至2100年期间未来气温上升幅度为1.1°C至6.4°C(2.0°F至11.5°F)。 图中概述了包含温室气体排放与全球变暖之间联系的多种模型的预测;所有模型都显示到2100年温度大幅上升。Various models of climate change which include “business-as-usual” increases in greenhouse gas emissions predict continuing increases in global temperature; this graph compares the projected increases to temperatures during the year 2000.
::各种气候变化模型,包括温室气体排放“一切照旧”增加,预测全球气温将继续上升;这一图比较了2000年预测的气温上升情况。Once again, then, we “have met the enemy” and “he is us.” What have we done? What are the environmental and socioeconomic consequences of this human disruption in atmospheric equilibrium?
::那么,我们又再次“遇到了敌人 ” , “他就是我们 ” 。 我们做了什么? 人类在大气平衡中破坏环境和社会经济后果是什么?A partial list of effects of climate change includes:
::气候变化影响的部分清单包括:Direct Physical Ecosystem Effects
::直接物理生态系统影响Numerous dramatic physical effects result from climate change. Many of these effects are listed below.
::气候变化产生了许多巨大的有形影响,其中许多影响列于下文。-
Melting of glaciers and a consequent rise in sea level, already documented (
Figure
)
::已经记录在案的冰川融化和由此造成的海平面升高(图) -
Sea level rise of 18-59 cm predicted by 2100
::预计到2100年海平面升高18-59厘米 -
River flooding followed by drought
::河水泛滥,随后发生干旱 -
Coastal flooding and shoreline erosion
::沿海洪水和海岸侵蚀
Glacial melting (left) and a rise in sea level (right) are two consequences of global warming. The left image shows the Larsen Ice Shelf B, which broke up during February of 2002 after bordering Antarctica for as long as 12,000 years. Excluding polar ice caps, 50% of glacial areas have disappeared since the turn of the century. Although sea levels have risen since the end of the last Ice Age, rates increased by a factor of 10 beginning about 1900.
::冰川融化(左)和海平面上升(右)是全球变暖的两个后果。 左边的图象显示拉森冰架B在2002年2月与南极洲接壤长达12 000年之后于2002年2月解体。 不包括极地冰盖,自本世纪初以来,50%的冰川地区已经消失。 尽管自上一个冰河时代结束以来,海平面已经上升,但从1900年左右开始,气温上升了10倍。-
Melting permafrost, leading to release of bog methane (CH
4
) increasing warming via positive feedback*
::熔化永久冻土,导致沼气(CH4)释放,通过积极反馈增加变暖* -
Changing patterns of
precipitation
::变化中的降水模式 -
Regional drought
::区域干旱 -
Regional flooding
::区域洪灾 -
Ocean warming, leading to increased
evaporation
::海洋变暖,导致蒸发增加 -
Increasing rainfall
::降雨量增加 -
Increasing erosion, deforestation, and desertification
::日益侵蚀、毁林和荒漠化 -
Release of sedimentary deposits of methane (CH
4
) hydrates – positive feedback*
::甲烷(CH4)水合物沉积沉积物释放——积极反馈* -
Ocean acidification: 0.1 pH unit drop already documented; 0.5 more predicted by 2100
::海洋酸化:已经记录了0.1 pH单位下降记录;2100年预测增加0.5 -
Loss of corals
::珊瑚损失 -
Loss of plankton and
::浮游生物和 -
Temperature extremes
::温度极端 -
Increasing severity of storms such as tropical cyclones, already documented (
Figure
)
::热带气旋等日益严重的风暴(图) -
Further reductions in the
Ozone
Layer (due to cooling of the stratosphere)
::臭氧层的进一步减少(由于平流层冷却)
The proportion of hurricanes reaching category 4 or 5 increased from 20% in the 1970s to 35% in the 1990s. The EPA and the World Meteorological Organization connect this increase to global warming, and NOAA scientists predict a continuing increase in frequency of category 5 storms as greenhouse gases rise.
::飓风达到4类或5类的比例从1970年代的20%上升到1990年代的35%。 美国环保局和世界气象组织将这一上升与全球变暖联系起来,诺阿科学家预测,随着温室气体的上升,5类风暴的频率会继续上升。Climate change has dramatic direct effects on Earth's . Some of these effects are listed below.
::气候变化对地球有着巨大的直接影响。以下列出了其中一些影响。-
Contributions to the Sixth
Extinction
reaching as much as 35% of existing plant and
.
::向第六次灭绝活动提供的捐款高达现有工厂的35%,以及...。 -
Decline in cold-adapted species such as polar bears and trout.
::北极熊和鳟鱼等冷适应物种的衰落。 -
Increase in forest pests and fires.
::森林虫害和火灾增加。 -
Change in seasonal species, already documented.
::季节性物种的变化,已经记录在案。 -
Potential increase in photosynthesis, and consequent changes in plant species.
::光合作用的潜在增加,以及植物物种随之而来的变化。 -
Loss of carbon to the atmosphere.
::碳流失到大气中。 -
Increasing fires, which together with deforestation lead to
positive feedback
, increasing carbon dioxide levels.
::火灾不断增多,再加上森林砍伐,导致积极反馈,二氧化碳水平上升。 -
Increasing decomposition of organic matter in soils and litter.
::有机物在土壤和垃圾中日益分解。
Note that at least three of the direct physical effects – melting permafrost, ocean warming, and forest fires/deforestation - can potentially accelerate global warming, because temperature increases result in release of more greenhouse gases, which increase temperatures, which result in more greenhouse gases – a positive feedback system aptly termed a “ runaway greenhouse effect .” Here’s how it could work: rising temperatures are warming the oceans and thawing permafrost. Both oceans and permafrost currently trap huge quantities of methane – beneath sediments and surface – which would undergo massive releases if temperatures reach a critical point. Recall that methane is one of the most powerful greenhouse gases, so the next step would be further increase in temperatures. Warmer oceans and more thawed permafrost would release more quantities of methane – and so on. These compounding effects are perhaps the most convincing arguments to take action to reduce greenhouse gas emission and global warming.
::请注意,至少三种直接物理效应 — — 融化永久冻土、海洋变暖和森林火灾/毁林 — — 有可能加速全球变暖,因为温度升高导致排放更多的温室气体,导致温度升高,导致更多的温室气体 — — 一个积极的反馈系统 — — 恰如其分地被称为“失控的温室效应 ” 。 这就是它如何发挥作用:气温升高正在使海洋升温和融化永久冻土。 海洋和永久冻土目前都困住大量甲烷 — — 沉积物和地表之下 — — 如果温度达到临界点,这些甲烷就会大量释放。 回顾甲烷是最强大的温室气体之一,因此下一步将是温度进一步升高。 温暖的海洋和更多的融化的永久冻土将释放更多的甲烷,等等。 这些复合效应或许是采取行动减少温室气体排放和全球升温的最令人信服的论据。Socioeconomic Threats Result From Some of the Above Changes
::由上述一些变化造成的社会经济威胁These include:
::这些措施包括:-
Crop losses due to climate and pest changes and desertification
::因气候和虫害变化以及荒漠化造成的作物损失 -
Increasing ranges for disease
vectors
(e.g., mosquitoes –
malaria
and dengue fever)
::病媒(如蚊子 -- -- 疟疾和登革热)的分布范围不断扩大 -
Losses of buildings and
in coastal areas due to flooding
::洪水造成的建筑物损失和沿海地区损失 -
Interactions between drought, desertification, and overpopulation leading to increasing conflicts (
Figure
)
::干旱、荒漠化和人口过多之间的相互作用导致冲突加剧(图)
A camp in Sudan houses refugees from the far western province of Darfur, who fled from genocide intensified by severe drought. The Darfur conflict echoes predictions that global warming may increase drought and desertification in overpopulated regions and result in more such tragedies.
::苏丹的一个难民营收容来自远西达尔富尔省的难民,他们逃离种族灭绝,因严重干旱而加剧,达尔富尔冲突与预测一致,即全球变暖可能会加剧人口过多地区的干旱和荒漠化,并导致更多此类悲剧。-
Costs to the insurance industry as weather-related disasters increase
::随着与天气有关的灾害增加给保险业造成的费用 -
Increased costs of maintaining transportation infrastructure
::运输基础设施维修费用增加 -
Interference with economic development in poorer nations
::干涉较贫穷国家的经济发展 -
scarcity, including pollution of
groundwater
::稀缺,包括地下水污染 -
Heat-related health problems
::与热有关的健康问题
Threats to Political Stability
::对政治稳定的威胁Threats to political stability as outcomes of global climate change include increased migrations due to poverty, starvation, and coastal flooding, and increased among peoples and/or nations for resources.
::全球气候变化对政治稳定的威胁包括贫穷、饥饿和沿海洪灾导致移徙增加,人民和(或)国家获取资源的情况增加。Giant Redwoods and Global Warming
::巨型红木和全球暖化Forest ecologist Steve Sillett is leading a team of scientists as they climb and measure every branch of some of the last and tallest old growth redwoods in California. Their goal is to learn how these ancient giants have historically responded to climatic shifts and to monitor how they are being impacted today by global warming.
::森林生态学家史蒂夫·西尔利特正在领导一组科学家,他们正在攀登并测量加利福尼亚州一些最后和最高增长的红木的每一个分支。 他们的目标是了解这些古老巨人历史上是如何应对气候变化的,并监测它们今天受到全球变暖的影响。Summary
::摘要-
Paleoclimatologists document changes in the Earth’s temperature over millions of years which cycle between tropical and ice age extremes – a variation of 10
o
C.
::Paleolimatistics记录了数以百万计的地球温度变化,这些变化在热带和冰河时代极端之间循环 — — 变化为10°C。 -
Greenhouse gases, especially CO
2
levels, often correlate with temperature changes.
::温室气体,特别是二氧化碳水平,往往与温度变化相关。 -
Deforestation and agriculture – by reducing levels of CO
2
uptake – may have initiated warming 8,000 years ago.
::砍伐森林和农业 — — 通过降低二氧化碳吸收水平 — — 可能在8000年前就开始变暖。 -
Most scientists today agree that fossil fuel combustion, deforestation, and agriculture contribute to greenhouse gases and the greenhouse effect.
::今天,大多数科学家一致认为,矿物燃料燃烧、砍伐森林和农业助长了温室气体和温室效应。 -
Global warming can cause physical changes for the Earth: melting of glaciers and permafrost, changes in precipitation patterns, temperature extremes, warming and acidification of the oceans, and ozone depletion.
::全球变暖可给地球带来物理变化:冰川和永久冻土融化、降水模式变化、极端温度、海洋变暖和酸化以及臭氧消耗。 -
Melting of oceans and permafrost can release methane, resulting in a “runaway greenhouse effect.”
::海洋和永久冻土的融化会释放甲烷,导致“远离温室效应”。 -
Ecological effects may include loss of biodiversity and addition of still more CO
2
to the atmosphere.
::生态影响可能包括生物多样性的丧失和大气中二氧化碳的增加。 -
Socioeconomic threats include crop losses, increased disease, water scarcity, and coastal flooding.
::社会经济威胁包括作物损失、疾病增加、缺水和沿海洪灾。 -
Population growth and socioeconomic factors (especially interference with third world development) can combine to produce political instability and conflict.
::人口增长和社会经济因素(特别是对第三世界发展的干扰)可能合在一起造成政治不稳定和冲突。
Review
::回顾-
Define and quantify global warming.
::界定和量化全球变暖。 -
What is estimated to be the difference between a glaciated Earth and an ice-free Earth?
::估计冰川地球和无冰地球之间的差别是什么? -
Summarize the evidence for greenhouse gases as the cause of global warming.
::概述温室气体作为全球变暖原因的证据。 -
What may be the most significance effect of of global warming on Earth’s ecosystems.
::全球变暖对地球生态系统的影响可能最为重大。 -
Relate global warming to current global stability.
::将全球变暖与当前的全球稳定联系起来。
-
Melting of glaciers and a consequent rise in sea level, already documented (
Figure
)
