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[科普知识] IPCC: 气候变化比原来认识的更严重

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    [LV.Master]无

    21#
     楼主| 发表于 2013-10-3 22:24:46 | 只看该作者
    山远空寒 发表于 2013-10-3 21:48 6 B" q" l' l$ x3 q3 [( @
    哇!专家就是厉害!佩服!
    2 [0 y, Q2 A+ q; ~4 e/ H6 W! b7 n
    ' k) u4 b9 r  T9 x  t. a原来洋流会如此严重的影响欧洲!那几百年前英国那次突然变冷也是洋流干的啦? ...

    - |$ T; z" p( E8 N我说的事件恢复起来可不会这么快。8200年前发生过一次大规模淡水进入北冰洋的事件,导致的气候变化花费了两百年的时间恢复。
    / X$ L( c9 X, t- H+ t, ?
    ; ~9 C- c5 T+ G2 L* d俄罗斯原来对于气候变暖是持无所谓态度的,一个原因就是气候变暖后西伯利亚会出现大量农业区,俄罗斯是受益者,而且俄罗斯因为经济崩溃,本身已经提前实现了大规模碳减排。不过近些年越来越多的森林火灾也能算到全球变暖头上的,所以俄罗斯最近又开始积极了一些。而且西伯利亚冻土有大面积解冻现象,那么建设在冻土上的建筑物几乎都要重新考虑地基问题,这也是一个相当大的投资。
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    ; h; G' O  g- o2 l/ i  {大规模的地貌变化,无论最终结果是好是坏,变化过程中的代价都是很大的,不这么好玩。6 j; }7 M5 [, g, x# @
    : q1 \. g' t: R0 V3 ^. ^, V  |
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    2020-10-30 18:27
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    [LV.3]辟谷

    22#
    发表于 2013-10-3 23:53:48 | 只看该作者

    你为嘛不加大时间尺度呢?

    下图为俄罗斯的沃斯托克站根据所采集的南极冰核所得到的地球大气以及温度变化图,跨越年代为42万年(自上而下第二条红线为温度变化图). Q% [; S% `) u) M7 g8 o

    % B( L+ l8 }) e' L& `! A& |: g9 o, M
    实际现在,地球是处于一个“小冰期”
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    23#
     楼主| 发表于 2013-10-4 00:09:09 | 只看该作者
    本帖最后由 橡树村 于 2013-10-4 00:24 编辑 ; r3 _2 a5 s# }1 p
    木不铎 发表于 2013-10-3 23:53 3 l1 z. C) I4 Z% P. w6 o
    下图为俄罗斯的沃斯托克站根据所采集的南极冰核所得到的地球大气以及温度变化图,跨越年代为42万年(自上而 ...

      ~6 p/ {3 G" X, R2 i- }" S7 s, w" I, h+ k+ c3 b1 K
    现在处于间冰期。小冰期的说法一直有,说得是如果没有人类活动影响,那么现在应该比几百年前平均气温低。5 K: e& H% Z. ^

    - [5 ^- k5 O: s, _0 {详细报告里面何止有四十万年前去年的气温复原,几百万年来的气温复原都有。
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    7 A) Z3 N2 U/ t1 d1 y/ X; J+ W  w' }" T

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    2019-6-16 23:34
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    [LV.10]大乘

    24#
    发表于 2013-10-4 00:19:08 | 只看该作者
    木不铎 发表于 2013-10-3 10:53
    1 D$ Q& }8 z* q+ G3 f+ e; F4 ?1 r下图为俄罗斯的沃斯托克站根据所采集的南极冰核所得到的地球大气以及温度变化图,跨越年代为42万年(自上而 ...

    & Y" \1 L( p1 x' N- g# @2 ]你这个图不正好支持报告所说的么。/ S, r3 j* ^7 X3 ?' P" |  R' ^! y. j) p! ^
    % r9 e% h1 D& G' n7 V9 a. K% F1 V
    图中从左到右,时间从现在往前推到42万年。可见最近1万来年,气温处于自然周期高点。在高点的基础上,目前观测结果是人类活动使得温度继续在升高,超过了自然波动。
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    [LV.9]渡劫

    25#
    发表于 2013-10-4 02:02:52 | 只看该作者
    二氧化碳浓度变化曲线为什么是那么均匀的锯齿?是测量手段的缘故么?
    ! d) J7 f: v  V6 H
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    26#
     楼主| 发表于 2013-10-4 02:18:37 | 只看该作者
    tanis 发表于 2013-10-4 02:02
    / V6 L3 d, k5 Z二氧化碳浓度变化曲线为什么是那么均匀的锯齿?是测量手段的缘故么?
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    那个是季节波动。春天夏天植物生长旺盛的时候二氧化碳浓度会降低,秋冬二氧化碳浓度会增高。
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    - Z, v6 w% ~2 r+ ~4 L. f( n- Z北半球因为陆地面积远大于南半球,所以波动非常明显。
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    27#
    发表于 2013-10-4 02:51:12 | 只看该作者
    橡树村 发表于 2013-10-3 12:18 - v& R  v) Y, Z) w1 l. v! E# Z
    那个是季节波动。春天夏天植物生长旺盛的时候二氧化碳浓度会降低,秋冬二氧化碳浓度会增高。
    / T+ B% p; d& Z3 v8 u  C7 ]( x5 {- _9 W0 x
    北半球因为 ...
    $ i- a  Y  @; U8 Q: X
    季节是每年都有的,这个图上的波动周期怎么也得有个几十年、上百年吧?
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    28#
     楼主| 发表于 2013-10-4 03:05:26 | 只看该作者
    本帖最后由 橡树村 于 2013-10-4 03:06 编辑 $ B  b  ]6 z3 P
    晨枫 发表于 2013-10-4 02:51
    & @% z: ?" o( q0 W! U9 W% X6 _% R季节是每年都有的,这个图上的波动周期怎么也得有个几十年、上百年吧? ...

    . Y' N1 j6 `% B* I* _( \
    & M4 m' Q* N! ?4 }% H! D$ M$ q, L/ V4 R7 p3 w$ }
    二氧化碳浓度的准确测量才六十年的历史。
    1 d, w: \$ x/ M* {& T9 ^
      W' W8 h$ [( ^3 l/ P4 I/ \' v一个周期是一年。
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    [LV.10]大乘

    29#
    发表于 2013-10-4 18:13:45 | 只看该作者
    村长好文,转发一篇在现场的NGO同事的報道$ J5 x% Y9 d, @$ }8 k6 ~! q5 H

    ( ]4 b. R7 L2 e0 M IPCC: How the Key Issues Were Resolved
    & ]7 _8 u0 v7 O( }+ ]! F! Y3 xThe Stockholm meeting that adopted the IPCC’s report on Climate Science saw governments and scientists debating several key issues before coming to a conclusion. Meena Raman who was at the meeting provides an account of the discussion on some key issues and how they were finally resolved." d, P4 N  [0 W- k0 V
    By Meena Raman2 X! [# z1 w+ D3 D/ d

    8 p8 `  }; F; l! [* g0 YPrior to the approval by governments of the Intergovernmental Panel on Climate Change (IPCC)'s ‘Summary for Policymakers' of Working Group I on the ‘Physical Science Basis', intense debates took place on several key issues.. w3 J: ?$ l( p7 K# X, t
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    Among the issues which were deliberated during the meeting of Working Group 1 (WG1), which began on 23 September in Stockholm, Sweden, included: the "pause" in the warming trend for the 15-year period from 1998 to 2012; the lack of temperature data for the pre-industrial period from 1750; the evaluation of climate models and their reliability in reproducing observations; the emission cuts needed by 2050 relative to 1990; and the carbon budget remaining in relation to temperature limits.1 \. V5 C( r" o1 d
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    Also addressed was the issue of ‘geo-engineering'.
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    Concerns raised by governments were in some cases referred to contact groups or informal consultations for resolution. The Summary for Policy Makers (SPM) was approved by governments on 27 September.( f: M/ r, w/ C' x0 `1 R; v) P
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    Below are highlights from some of the discussions.
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    ‘PAUSE' IN WARMING! z2 P( n- y% b. C

    1 i" s" v: |+ aWhen the initial draft of the SPM (dated 7 June 2013) was made available to governments, a key issue of concern was reference to "the global mean surface temperature trends, where the rate of warming over the past 15 years (1998-2012) was smaller than the trend since 1951". (This has been referred to in the media as a ‘pause' in the warming).
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    % x) C% p& X! M, L; W4 ?9 D"The mean rate of warming for the 15 years was 0.05 degree C compared to the mean rate per decade (1951-2012) of 0.12 degree C," according to the SPM.
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    ; ~1 R5 z% E& j& e& J2 QAccording to Thomas Stocker (Switzerland), who is the co-chair of WG1, concerns were raised by some governments regarding the scientific basis of looking at short term periods. He said that an equal number of governments felt that this (15 years) is an important period of time on which the IPCC has to make a statement on a scientific basis.
    : H7 W4 ^0 ~! t: K' O ; a/ |" y2 y3 g6 n$ x. c' }
    During the meeting, several governments including Germany, Switzerland and the United States said that it is important to discuss the 15 years as this is now in the public domain and explanation is needed.
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    ' ~( `; }, h, {) C9 QGermany stressed that showing trends alone is misleading and there is need to also show the context. It said that the impression given is that warming is going to slow down or is halted. It wanted reflection of the trends for the following 15 years.
    9 v, @' t+ M1 U& y - A* [5 F7 o  _$ U, z0 P8 P( D+ s( ]
    This was however not agreed to.1 T# k: |2 z) B% Q  }

    ; l, j9 ?$ B" L/ Q& v* ]The US emphasised the need to address inter-annual variability. It also wanted the mention of 1998 being an El Nino event. The US said that the rate of warming since the late 1990s is very sensitive to choice of start dates.
    3 _! b. r5 X5 j8 o9 H6 ~ % ]$ a( ?6 W4 g' r) C* M0 b) C
    (An El Nino event is a temporary change in the climate of the Pacific Ocean, in the region around the equator where effects are seen in both the ocean and atmosphere, generally in the Northern Hemisphere winter. Typically, the ocean surface warms up by a few degrees Celsius).; z, Z( H# L. Q: a% L8 r9 f3 ]
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    China said that it is important to reflect the temperature changes which are a fact and to also reflect the short term uncertainty.  f$ x5 Y$ G4 ~

    . v1 A: K/ j, L! ^: y+ DSaudi Arabia stressed the need to state the internal climate variability.
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    The final paragraph agreed to is as follows: "In addition to robust multi-decadal warming, global mean surface temperature exhibits substantial decadal and inter-annual variability. Due to natural variability, trends based on short records are very sensitive to the beginning and end dates and do not in general reflect long-term climate trends. As one example, the rate of warming over the past 15 years (1998-2012; 0.05 [-0.05 to +0.15] degrees C per decade), which begins with a strong El Nino, is smaller than the rate calculated since 1951 (1951-2012; 0.12 [0.08 to 0.14] degrees C per decade)."
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    & w% i0 Y5 R3 b5 kA footnote was added that reads: "Trends for 15-year periods starting in 1995, 1996, and 1997 are 0.13 [0.02 to 0.24], 0.14 [0.03 to 0.24], 0.07 [-0.02 to 0.18] degrees C per decade, respectively."7 c5 v# D# S# e( h+ J6 p5 P

    ) @& B( P2 q6 M' U. wLACK OF TEMPERATURE DATA FOR PRE-INDUSTRIAL PERIOD
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    During the discussion on ‘observed changes to the climate system' relating to the atmosphere, an issue which arose was the reference year used.5 E* `9 r* f5 Q4 D9 b; R/ @

    ! E# T. J$ ~. T; lIn the initial draft circulated to the governments in June, the paragraph of concern read as follows: "The globally averaged combined land and ocean surface temperature data show an increase of 0.89 [0.69 to 1.08] degrees C over the period 1901-2012. Over this period, almost the entire globe has experienced surface warming."
    ; J% r& c4 x2 b8 W- ~6 f ; R+ ~+ e+ y5 X2 N2 ?# V
    The Netherlands said that the SPM did not make clear why 1901 was chosen, and asked why different sections used different reference years. It referred to negotiations under the United Nations Framework Convention on Climate Change (UNFCCC), where the reference year is 1990 and there is agreement to hold the increase in global average temperature to below 2 degrees C above pre-industrial levels. It suggested the use of the period 1850-2012." \' T9 O: z$ N
    $ t3 o, N: C# R1 ^+ Z. }
    This was supported by Norway, which added that it is important to peg the reference year to the pre-industrial level of 1850.
    ' e+ w9 N! {' T- G. Z* p1 e' D; r ! W$ [. r$ v1 [1 W: z/ E( H# i
    St. Lucia also agreed with the Netherlands that it is important to have a consistent reference period from 1850 for policymakers./ F+ r0 `% Z, ]' f+ P" I
    # X6 z8 e1 `5 ]  C* j0 N
    In response, the authors (who are scientists) said there are several reasons for choosing 1901 to 2012, as they wanted to highlight the long-term change and that before 1901, data coverage and quality was sparse, hence the focus on 1901. The other reason is that comparison with previous SPMs (of previous IPCC assessments) is now possible because they also start in 1901.
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    3 E+ S1 \% F9 TStocker said that 1901 is a conscious choice because of the availability of the datasets.
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    ; {: G. m- Y" e  B5 L" C! UThe Netherlands insisted that for policymakers, 1850 is the relevant period for the 2 degree C. Germany also said that the temperature estimate between 1850 to 1901 is important.0 V1 q6 L9 Z  A0 @9 Y
    ( ^: [! O1 R3 t4 ?% [7 Z" p
    Stocker, in response, said the temperature figure for the period 1880-2012 could be given as this is the result from three datasets.1 }/ S7 _( V$ h  S. r8 d" y5 ~

    " U$ \5 P9 E' T6 VThe United Kingdom also wanted a reference to the pre-industrial period as this is what is referred to in the Convention.
    , l# y! A8 v) A, b+ H* U/ l! F ( Y$ v- q- C5 ^! y% ^
    Germany referred to the IPCC's 4th Assessment Report (AR4) where the total temperature increase was from 1850-1999 and from 2001-2005. It wanted the authors to provide figures that allow for direct comparability.
    , [1 B6 d0 e7 f: h: @5 Z
    , l% S) V% D0 \& K( n4 B3 m/ DIndia said that it would be appropriate to give the same period and give direct comparison with AR4 time periods. If there are data limitations, qualifying statements about the limitations of that figure should be provided.5 l( Y- U: M) K/ m
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    Stocker also clarified that on the use of the term ‘pre-industrial', that term is used to refer to the period that goes back to 1750. So, the period from 1850 is what we would call as early instrumental period, and then from 1900, is the period with instrumental observations.
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    ! D( ]) Y% F8 j2 f0 @4 s6 ?The authors reiterated that the datasets on global scale go back only to 1850; there are sparse observations that go back to 1750 on a global scale.9 {, k6 U. j! O! P7 z- G
    7 z" l1 D. \9 J9 ]; }6 M' S
    The UK said that there must be some way of addressing the issue of the ‘pre-industrial' period. Germany said that there could be text to say "pre-industrial, approximated by 1850-1900".
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    " p& h& w" j1 g4 vBrazil said that the pre-industrial period refers back to 1750, and it did not think one can use 1850 as an approximation for that as there is a difference of 100 years.
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    / z/ q- m2 x! F. c5 CGiven the lack of consensus in this regard, an informal consultation group was formed to discuss the issue.
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    / b: Q' U1 q& L! Q  e& l6 mFollowing the informal consultation, what was finally agreed to is as follows: "The globally averaged combined land and ocean surface temperature data as calculated by a linear trend, show a warming of 0.85 [0.65 to 1.06] degrees C, over the period 1880-2012, when multiple independently produced datasets exist. The total increase between the average of the 1850-1900 period and the 2003-2012 period is 0.78 [0.72 to 0.85] degrees C, based on the single longest dataset available."/ w& q6 m+ [9 t6 Z4 Y; E
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    A footnote was added at the end of the paragraph which reads: "Both methods presented in this bullet were also used in AR4. The first calculates the difference using a best fit linear trend of all points between 1880 and 2012. The second calculates the difference between averages for the two periods 1850 to 1900 and 2003 to 2012. Therefore, the resulting values and their 90% uncertainty intervals are not directly comparable."
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    ; q8 Y4 a5 h  L9 R& dEVALUATION OF CLIMATE MODELS9 u  K1 ~' {3 G7 ^
    1 ]) k: b5 Q' w8 R% {: }
    The SPM which was approved states that "understanding recent changes in the climate system results from combining observations, studies of feedback processes, and model simulations. Evaluation of the ability of climate models to simulate recent changes requires consideration of the state of all modelled climate system components at the start of the simulation and the natural and anthropogenic forcing used to drive the models. Compared to AR4, more detailed and longer observations and improved climate models now enable the attribution of a human contribution to detected changes in more climate system components"./ ~# k3 F" B/ ^4 t1 {) s9 S% R& V

    3 Q3 v& [2 w5 Y, _6 F# KIn the SPM, under the section on ‘understanding recent changes in the climate system', one aspect relates to the ‘evaluation of climate models'.: p# J: L) _* q: P, [& b

    3 n. L, E3 D2 q+ I, Z4 {+ k' _4 a0 yIn this regard, in the June version of the draft of the SPM, there was a statement that "there is very high confidence that models reproduce the more rapid warming in the second half of the 20th century and cooling immediately following large volcanic eruptions. Models do not generally reproduce the observed reduction in surface warming trend over the last 10-15 years. There is medium confidence that this difference between models and observations is to a substantial degree caused by unpredictable climate variability, with possible contributions from inadequacies in the solar, volcanic, and aerosol forcings used by the models and, in some models, from too strong a response to increasing green-house gas forcing.": P! Y1 X! M1 e3 \  E+ v

      j: P4 p. c) i, P, AFollowing comments by various governments prior to the meeting in Stockholm, the authors amended the above paragraph to read as follows: "The long-term climate model simulations show a trend in global-mean surface temperature from 1951- 2012 that agrees with the observed trend, despite differences between simulated and observed trends over the past 10-15 years (very high confidence)."! C% h# e  A, J4 X$ i

    3 z9 @: U# ?4 b/ x5 e"The observed reduction in surface warming trend over the period 1998-2012 as compared to the period 1951-2012, is due in roughly equal measure to a reduced trend in radiative forcing and a cooling contribution from internal variability, which includes a possible redistribution of heat within the ocean (medium confidence). The reduced trend in radiative forcing is primarily due to volcanic eruptions and the timing of the downward phase of the 11-year solar cycle. However, there is low confidence in quantifying the role of changes in radiative forcing in causing the reduced warming trend. There is medium confidence that internal decadal variability causes to a substantial degree the difference between observations and the simulations; the latter are not expected to reproduce the timing of internal variability."4 [! Q7 i2 b/ f
    3 X2 n: Z! e; T2 ^
    (Levels of confidence is the IPCC indicator for the robustness of conclusions drawn from the data and literature that is assessed.)% p+ {: _3 @1 D4 v4 V: B' t

    ( v& v3 g7 W& a7 F. h2 J3 K# GVenezuela sought clarification over the ‘very high confidence' judgement by the authors while China said that the paragraphs above were new and are supposed to be an evaluation of the climate models. It wanted to know the advantages and disadvantages of the models and said the June version of the SPM draft had this.9 p/ B3 q6 u* v0 C

    9 [7 n8 i5 I8 w5 F# ~0 A9 JSimilar sentiments were expressed by Saudi Arabia.- W  W& @! L; T7 j. t

    5 j" J( y1 R% oThe United States said the paragraphs did relate to the evaluation of the models and it is about observations in a broader context and not just 10 to15 years. Switzerland said that one could not test models in 15 years.
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    8 `* l9 R( @2 X" Q; YSaudi Arabia, referring to the Technical Summary of WG1, wanted the following sentence added: "Most, though not all, models overestimate the observed warming trend in the tropical troposphere over the last 30 years, and tend to underestimate the long-term lower-stratospheric cooling trend."9 b) d, }7 c7 l* N* w( A9 E

    ; o. G  Z7 q  Y% [(The Technical Summary is drawn from the full report of the Working Group.)
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    Following consultations with the authors, the following compromise was reached at around 2 am on Thursday, 26 September: "The long-term climate model simulations show a trend in global-mean surface temperature from 1951 to 2012 that agrees with the observed trend (very high confidence). There are, however, differences between simulated and observed trends over periods as short as 10 to 15 years (e.g., 1998 to 2012)."
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    # V: t1 [7 Z# f; m"The observed reduction in surface warming trend over the period 1998-2012 as compared to the period 1951-2012, is due in roughly equal measure to a reduced trend in radiative forcing and a cooling contribution from internal variability, which includes a possible redistribution of heat within the ocean (medium confidence). The reduced trend in radiative forcing is primarily due to volcanic eruptions and the timing of the downward phase of the 11-year solar cycle. However, there is low confidence in quantifying the role of changes in radiative forcing in causing the reduced warming trend. There is medium confidence that internal decadal variability causes to a substantial degree the difference between observations and the simulations; the latter are not expected to reproduce the timing of internal variability. There may also be a contribution from forcing inadequacies and, in some models, an overestimate of the response to increasing greenhouse gas and other anthropogenic forcing (dominated by the effects of aerosols.)"
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    When the meeting resumed on the final day at around 8 am, Germany requested a reconsideration of the last sentence in the paragraph above as it had concerns.' W, J3 N8 A8 n* ~

    $ Q4 f. X& t. \& @3 Z$ ^1 uSince agreement on the above paragraph had been gavelled, Stocker did not want a re-opening of the agreed text.6 `6 X! n! W1 t, M% Z
    4 E2 Q' N' R% h6 r& U7 G2 z
    EMISSION REDUCTIONS REQUIRED BY 2050
    ; f" e4 C( C) Q# U6 R5 t # D, I3 U9 v; ?* q/ g/ P- ~
    Under the discussion on ‘Future global and regional climate change', the SPM which was approved states that: "Projections of changes in the climate system are made using a hierarchy of climate models... These models simulate changes based on a set of scenarios of anthropogenic forcings. A new set of scenarios, the Representative Concentration Pathways (RCPs), was used for the new climate model simulations... In all RCPs, atmospheric CO2 concentrations are higher in 2100 relative to present day as a result of a further increase of cumulative emissions of CO2 to the atmosphere during the 21st century."
      z+ j5 N: H" u, v" L6 }
    4 n7 U- c( \- p(The four RCPs used are RCP2.6, RCP4.5, RCP6, and RCP8.5, and named after a possible range of radiative forcing values in the year 2100).
    " u; g. h3 c  i; z( @( j! s$ ^4 T + K2 }# V; A! P1 s& M
    One aspect that was discussed in this regard related to ‘carbon and other biogeochemical cycles'.# h. @; e0 R: u6 r
    : [) h& E* i. g; Q/ L
    Member States were asked to consider the following statement: "Based on Earth System Models, following RCP2.6 requires by 2050 an average emission reduction of 50% (range 14% to 96%) relative to 1990 emissions, and requires, about as likely as not, sustained net removal of CO2 from the atmosphere by the end of the 21st century."" B! D9 g' k% {" i+ {4 @8 t7 b  }* B

    ' V+ s. C; ~3 i: Q2 BGermany wanted additional information on the emissions pathway beyond 2050 and asked for a figure for emissions reduction in 2080.1 J) j" |3 A- V) D4 F* a

    2 R, s$ ?  W, N2 I8 A' v+ N3 j* c/ BChina expressed concerns as to how one single figure is obtained and asked how the 50% figure was obtained when this is not what the ranges indicate. It also said that no information has been provided from other scenarios and that only one scenario in RCP2.6 is considered.
    * u: {: F: ~- U; n# a: G
    , t" \4 }7 z9 S  D. ~* o) _4 [0 kSaudi Arabia said that members are talking about projections that would resonate with policymakers. It can be misleading to talk about a range from 14% to 96%. It wanted the entire paragraph deleted. Russia also had similar concerns.7 X% {) |; D) }' {1 B$ @
    3 r2 T9 Q' l0 k$ t- g  N: p2 ~/ i' {
    A contact group was formed to address this issue. Following the discussions, the following paragraph was agreed to: "By 2050, annual CO2 emissions derived from Earth System Models following RCP2.6 are smaller than 1990 emissions (by 14% to 96%)... By the end of the 21st century, about half of the models infer emissions slightly above zero, while the other half infers a net removal of CO2 from the atmosphere."6 f. m; j; w/ Z- V% {

    2 i+ ^' i# T; X) q: cCARBON BUDGET6 ?4 [: X! ~, J# F' ^

    " u! B% |0 k& W8 E4 o- t+ J3 MIn the discussion on ‘climate stabilisation', Member States were asked to consider the following paragraph: "Limiting the warming caused by anthropogenic CO2 emissions alone to likely less than 2 degrees C relative to pre-industrial, will require cumulative CO2 emissions from all anthropogenic sources to stay below about 1000 GtC since the beginning of the industrial era. This amount is reduced to about 800 GtC when accounting for non-CO2 forcings as in RCP2.6. An amount of 545 [460 to 630] GtC, was already emitted by 2011."
    ) S: C2 o( L3 Y7 F4 @- {9 B  @ 6 y% m5 @4 k# _4 r* a, P- W" t; c
    China raised concerns that the cumulative reductions required to stay below 2 degrees C are not consistent with the figures in the underlying assessment report of WG1 which reflect that emission reductions should be in the range of 800-2500 GtC between 1750 to 2100.
    , \: t5 T0 n7 D: V1 B 6 y# Y7 `/ C3 q3 P2 J
    The US said that the IPCC is supposed to be policy neutral and the information needs to be presented in a neutral way.
    ( g! j: J5 m: s: F/ ~+ z" T ' k1 l6 M& j$ E% i- h: d* L
    Informal consultations were held in this regard and the text which was agreed is as follows: "Limiting the warming caused by anthropogenic CO2 emissions alone with a probability of >33%, >50%, and >66% to less than 2 degrees C since the period 1861-1880, will require cumulative CO2 emissions from all anthropogenic sources to stay between 0 and about 1560 GtC, 0 and about 1210 GtC, and 0 and about 1000 GtC since that period respectively. These upper amounts are reduced to about 880 GtC, 840 GtC, and 800 GtC respectively, when accounting for non-CO2 forcings as in RCP2.6. An amount of 531 [446 to 616] GtC, was already emitted by 2011."
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    GEO-ENGINEERING0 R* i# s6 y6 x9 C

    9 t1 X3 x: S7 vAnother issue in the SPM concerns ‘geo-engineering'
      z2 v! T9 l$ ]+ E0 y1 d) u
    * O) f$ [9 D- TMember States were asked to consider the following statement: "Methods that aim to deliberately alter the climate system to counter climate change, termed geo-engineering, have been proposed. Limited evidence precludes a comprehensive quantitative assessment of both Solar Radiation Management (SRM) and Carbon Dioxide Removal (CDR) and their impact on the climate system. CDR methods have biogeochemical and technological limitations to their potential on a global scale. There is insufficient knowledge to quantify how much CO2 emissions could be partially offset by CDR on a century timescale. Modelling indicates that SRM methods, if realizable, have the potential to substantially offset a global temperature rise, but they would also modify the global water cycle, and would not reduce ocean acidification. If SRM were terminated for any reason, there is high confidence that global surface temperatures would rise very rapidly to values consistent with the greenhouse gas forcing. CDR and SRM methods carry unintended side effects and long-term consequences on a global scale."+ }8 h6 \* o) j; k/ ^" {. K0 T  J
    : k; D' m6 M6 _! o5 B6 i) {! |
    The US raised concerns over the last sentence, as it felt that it overstated the state of science in that the side effects are known and that they were unintended. It wanted reflection of the uncertainties in understanding.* V: E' v9 z3 B* i% k3 @8 f
    ( A+ G$ O+ v# E5 E( e0 E% X
    The authors responded that there is evidence of the side effects but were prepared to delete the word ‘unintended' from the last sentence. This led to agreement of the text.9 x2 f7 n& A+ I: @; W

    4 w: ^1 v4 q" R* kAuthor: Meena Raman is legal advisor of Third World Network.
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    [LV.6]出窍

    30#
    发表于 2013-10-4 21:35:36 | 只看该作者
    本帖最后由 山远空寒 于 2013-10-5 10:10 编辑
    3 g" p! u( M, y3 X" A  T- ]
    橡树村 发表于 2013-10-3 22:24
    , y; f, r: Y3 R% m& D9 }我说的事件恢复起来可不会这么快。8200年前发生过一次大规模淡水进入北冰洋的事件,导致的气候变化花费了 ...

    & ]# B$ U8 K0 t$ m" S$ Z: O: P; b  E" R& q
    之前我觉得对新疆、对西部好,现在完全同意村长的意见,气候变化如果太快,我们人类可能受不了。/ X. R0 \1 C4 `
    0 C% M' F* D# e! q  G) h
    最好减缓这种变化,有个几百年慢慢的过度,至少我们能在太空种出粮食,就不怕了。

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    31#
    发表于 2013-10-6 04:39:35 | 只看该作者
    雪个 发表于 2013-10-2 17:57
    $ G/ R1 z' D7 }% M1 t嗯,也不能拿一个地方的数据来说明问题。老有人跟我说“明明比以前冷,偏要说全球变暖!” ...
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    主流难道不是每年冬天都在高喊全球变暖是扯淡,每年夏天都在高喊全球变暖果然是大问题哎么。。。。

    点评

    哈哈  发表于 2013-10-6 07:04
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    [LV.Master]无

    32#
    发表于 2013-11-17 12:24:31 | 只看该作者
    本帖最后由 heinsect 于 2013-11-17 12:37 编辑 3 u& p7 r6 r! A8 [
    9 j. l1 E8 U# Q( P( H
    有人反对IPCC的数据,说这也是个利益集团。IPCC的很多人是曾在GreenPeace、WWF任职,很多人出身于大化工企业。IPCC报告的数据来源、方法都有很多问题,不是严格的科学成果。很多报告作者的资质也有问题,比如其中一个只是硕士研究生。
    . J6 ~$ o, {2 K/ `# L- u8 _1 x: l
    & X, p) K3 O: K, n! ~' o( [& r+ j来源:
    3 n8 c8 F4 I5 x' _  N& U, PDonna Laframboise is a Canadian journalist and writer, whose latest book is Into the Dustbin: Rajendra Pachauri, the Climate Report & the Nobel Peace Prize.
    / u! Z+ h  f" l( X: m. N1 E
    & e1 Y) ]" d& R( @  F  J0 ewiki:
    ' g3 T; _* H2 i: [$ d/ AIn 2010, Laframboise organized a citizen audit of the IPCC AR4 report, to determine how many of the report's sources were peer-reviewed. The audit found that 21 of the report's 44 chapters used less than 60% peer-reviewed sources.[4][5] She maintains noconsensus.org, a website that argues that there is no scientific consensus on global warming.[4][6]
    6 X) X* s) ~& Q! J0 u# Y& M
    $ Z+ g  X" v3 h7 A* _' @这是她的博客:) y5 y+ P8 d, Z/ a5 o2 p4 j
    http://nofrakkingconsensus.com/
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    [LV.Master]无

    33#
     楼主| 发表于 2013-11-17 13:04:03 | 只看该作者
    heinsect 发表于 2013-11-17 12:24 ( W* @: O& ?) @1 I5 \
    有人反对IPCC的数据,说这也是个利益集团。IPCC的很多人是曾在GreenPeace、WWF任职,很多人出身于大化工企 ...

    4 @: k7 e2 b. K& o) j没有科学意义的指责而已。
    * V- M% A) X3 f
    " f% G) w! o) t, f' [现在还对全球变暖本身持怀疑态度的不是智商有问题就是拿黑心钱的了。
    ' ^1 O3 M- ]! A: S0 G
      C4 l- J0 j4 p: P反IPCC方的多数都不待见这种人了。

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