论文标题
一氧化二氮和气候
Nitrous Oxide and Climate
论文作者
论文摘要
由于辐射强迫的增加，预计较高浓度的大气一氧化二氮（N2O）会稍微温暖地球表面。辐射强迫是通过透明的气氛和辐射通过与温室气体相同的大气中的透明气氛和辐射的净向上热辐射通量的差异。通常在W/M^2中测量的辐射强迫取决于纬度，经度和海拔高度，但通常为Tropopause引用，温带纬度的高度约为11 km，或在90公里处的大气顶部。对于当前的温室气体浓度，每个添加的N2O分子的辐射强迫大约是每个添加的二氧化碳（CO2）分子的强迫大约230倍。这是由于相对丰富的温室气体二氧化碳的吸收带的饱和度与痕量温室气体N2O的吸收带的饱和相比，相对丰富的温室气体CO2的饱和度。但是，二氧化碳分子的增加速率约为2.5 ppm/年（ppm =摩尔的零件），比N2O分子的增加速率大约3000倍，自1985年以来，N2O分子的增加速率约为0.00085 ppm左右。因此，一核氧化物的贡献至每年增加230/3000/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1/1。如果主要的温室气体二氧化碳，CH4和N2O在过去几十年中观察到的变暖中贡献了约0.1 c/十年，则这将对应于每年约0.00064 K，或N2O的每世纪每世纪温暖的0.064 K。由于恐惧的恐惧，对一氧化二氮排放的强烈限制的提议并不能被这些事实证明是合理的。限制会造成严重伤害；例如，通过危害世界食品供应。
Higher concentrations of atmospheric nitrous oxide (N2O) are expected to slightly warm Earth's surface because of increases in radiative forcing. Radiative forcing is the difference in the net upward thermal radiation flux from the Earth through a transparent atmosphere and radiation through an otherwise identical atmosphere with greenhouse gases. Radiative forcing, normally measured in W/m^2, depends on latitude, longitude and altitude, but it is often quoted for the tropopause, about 11 km of altitude for temperate latitudes, or for the top of the atmosphere at around 90 km. For current concentrations of greenhouse gases, the radiative forcing per added N2O molecule is about 230 times larger than the forcing per added carbon dioxide (CO2) molecule. This is due to the heavy saturation of the absorption band of the relatively abundant greenhouse gas, CO2, compared to the much smaller saturation of the absorption bands of the trace greenhouse gas N2O. But the rate of increase of CO2 molecules, about 2.5 ppm/year (ppm = part per million by mole), is about 3000 times larger than the rate of increase of N2O molecules, which has held steady at around 0.00085 ppm/year since 1985. So, the contribution of nitrous oxide to the annual increase in forcing is 230/3000 or about 1/13 that of CO2. If the main greenhouse gases, CO2, CH4 and N2O have contributed about 0.1 C/decade of the warming observed over the past few decades, this would correspond to about 0.00064 K per year or 0.064 K per century of warming from N2O. Proposals to place harsh restrictions on nitrous oxide emissions because of warming fears are not justified by these facts. Restrictions would cause serious harm; for example, by jeopardizing world food supplies.
