by ∼7 ppm in the following ∼20–50 years. After that, CO2slowly decreased with a local minimum at 1650 ∼ 1750 A.D. CO2began to rise at ∼1750 A.D., reached levels above the range of variability of the previous 850 years at ∼1850 A.D., and has rapidly increased since...
According to the following four objective indicators-total emissions allowance from 1900 to 2050, actual emissions from 1900 to 2005, emissions levels in 2005, and the average growth rate of emissions from 1996 to 2005-all countries and regions whose population was more than 300000 in 2005 were...
[OCpetro] is the OC concentration in rock (mass × mass−1) andχis the weathering intensity as the fraction of OCpetroweathered from rock. Weathering intensityχhas been shown to vary between low values of 0.2 in highly erosive settings7and very high values of 0.98...
Atmospheric carbon dioxide (CO 2 ) levels before the industrial revolution were 260–280 p.p.m.v. (parts per 10 6 by volume) as determined from studies of air trapped in ice 1,2 . We report here similar results, using Antarctic ice, for the CO 2 levels during the seventeenth and eig...
30 yr of this century, recorded levels of d13C show an unexpected decline which could not have been caused even by complete retention of all the fossil CO2 introduced into the atmosphere. Furthermore, the CO2 levels deduced from our d13C values for 1900?1920 agree well with those of ...
This for two reasons: first, the temperature increase appears before the claimed increase in CO2; and sec- ond, there are monotonically low proxy CO2 levels in the ice cores during the periods of warm climate, both in ancient and modern times. In the ice cores, the isotopically determined ...
Nevertheless, our data indicate a fast recovery in most countries by the end of June except in the U.S., Brazil, and India where the number of COVID cases continued to remain high. In China, we even observed a rebound of emissions above the levels of 2019 as early as the beginning ...
Third Assessment Report confirms that CO2 enrichment under field conditions consistently increases biomass and yields in the range of 5-15%, with CO2 concentration elevated to 550 ppm Levels of CO2 that are elevated to more than 450 ppm will probably cause some deleterious effects in grain quality...
表3不同CO2浓度鳗草植株光合色素含量的变化(平均值士标准差) Table 3 Changes in photosynthetic pigmentcontents of Z. marina plants under different CO2 levels during the experiment (Mean士SD) 光合色素 PhotosyntheticYigment 380X10-6 实验组 Treatments 750X10-6 1900X10-6 633X10-6〜1900X10-6 F ...
Computational data at MP2/6-311++G(2d,2p) and ωB97X-D/6-31+G(d,p) levels suggested FE:CO2 ratios and likely structural arrangements of each cluster based on comparisons with experimental rotational constants. Graphical abstract Download: Download high-res image (136KB) Download: Download ...