天然气水合物与全球气候变化的关系

Relation of Gas Hydrates and Global Climate Changes

天然气水合物是一种广泛地存在于海底沉积物和陆地高纬度永久冻土带中的矿物,含碳量超过全球所有其他来源有机碳的总和。然而天然气水合物在自然界极不稳定,温压条件的微小变化都会引起其分解而释放出甲烷气体。一般情况下,释放出的甲烷大部分可能会被氧化成CO2而溶解在海水中,进入大气中的量不足以对气候产生影响。只有在发生巨变事件的情况下,如海底大规模的沉积物滑塌,才会将大量的甲烷带到海面并释放到大气中,从而对全球气候和环境产生严重的影响。因此,在开发利用天然气水合物之前,必须有超前的防范措施,以防止或尽可能减少天然气水合物对环境造成的不良影响。

Gas hydrate, a mineral that exists in marine and terrestrial environments, accounts for a large quantity of organic carbon, exceeding the total organic carbon from all other sources. However, gas hydrates is instable in nature, a slight variation of temperature/pressure would cause the decomposition of gas hydrates. Under steady - state conditions, much of the methane released into water column would be dissociated to carbon dioxide before reaching the sea surface. The amount of methane released into atmosphere is too little to impact global climate. Only catastrophic events such as large - scale sediment slumping would lead to considerable turbulence in the overlying water mass. Under these conditions, it is probable that a much higher proportion of the methane would be brought up to the sea surface and released to the atmosphere. Such events would have an immediate impact on global climate and global environment. Therefore, conscious and technological measures must be taken to prevent or decrease vari- ous environment hazards triggered by gas hydrate exploitation.