Historical Climate Changes (CO_2 Increase) and the Prediction (Preliminary Sutudy) --Using Japanese, Canadian and French Tree Rings--

树木年轮对温室气体（CO_2）浓度历史变化的初步分析——利用日本-加拿大-法国树木年轮。为了查明最近空气中二氧化碳浓度增加的原因，记录长期环境条件的树木年轮可能是最可靠的方法。合理的原因包括：(1)人类燃烧化石燃料，产生较低的稳定碳同位素比（^<13>C/^<12>C或δ ^<13>C），(2)其他人类活动，如从森林中创造农田，(3)自然现象，如深海洋流的变化，以及(4)上述三种因素的综合。利用冰芯测定近1000年来co2浓度变化受到气泡形成时间分辨率低的限制。树木年轮中晚期木材的纤维素可能更准确地记录了周围环境条件的变化，包括空气中的二氧化碳浓度。树木的年轮不仅能清晰地记录几千年的历史，而且还能在自然环境中保存几千年的枯木。来自德国的数据表明，最近二氧化碳的快速增加不仅仅是由人类燃烧化石燃料的活动造成的。这项调查的目的是利用日本的树木年轮来验证这一信息。一棵典型的78年树龄杉树（Cryptomeria japonica D.Don）在温度、湿度和降水与欧洲不同的环境中收获。将树木年轮分成7个样品(1)1920-29,(2)1930-39，…，用质谱仪得到δ ^<13>C值。(7) 1980 - 88。样品(1)、(3)、(5)和(7)的δ ^<13>C分析值分别为-22.31*、-22.65*、-23.35*和-24.03*。分析数据的数量仅限于四个样本，因此很难从这个初步调查中得出确凿的结论。然而，可以表达两个发现：(1)使用日本sugi测量delta^<13>C值是可能的；(2)获得的delta^<13>C值在合理范围内。少

Preliminary Analysis of Tree Rings for Historical Changes of Greenhouse Gas (CO_2) Concentrations--Using Japanese-Canadian-French Tree Rings.In order to pinpoint the causes of recent increase in CO_2 concentrations of the air, tree rings which record long term environmental conditions can be the most reliable method. The plausible causes include : (1) human combustion of the fossil fuels which produce a lower stable carbon isotopic ratio (^<13>C/^<12>C or delta^<13>C), (2) other human activities such as creation of farm land from forest, (3) natural phenomena such as a change of deep ocean current and (4) a combination of the above three. The usage of ice cores determining the concentration changes of CO_2 during the last 1000 years is limited by the low time resolution of air bubble formation.The cellulose of the late wood in tree rings may have been recording more accurate changes ot the surrounding environmental conditions including CO2 concentrations in the air. Tree rings have not … More only the clear record of the history up to several thousand years but also dead wood could be preserved for many millennium in the natural environment. The data from Germany suggested that the recent rapid CO2 increase was not caused solely by the human activity of fossil fuel burning.The objective of this investigation was to validate this information using tree rings from Japan. A typical 78 years old sugi tree (Cryptomeria japonica D.Don) was harvested from an environment where temperature, humidity and precipitation are different from those obtained in Europe. The delta^<13>C values were obtained using a mass-spectrometer after the tree rings were separated into 7 samples : (1) 1920-29, (2) 1930-39, .. (7) 1980-88. The delta^<13>C analysis of sample (1), (3), (5) and (7), were -22.31*, -22.65*, -23.35* and -24.03*, respectively. The number of analytical data were limited to four samples, thus it is very difficult to draw substantiated conclusions out of this preliminary investigation. Two findings, however, can be expressed : (1) it is possible to measure delta^<13>C values using Japanese sugi and (2) the obtained delta^<13>C values were in a reasonable range. Less