Human depletion of underground reservoirs has shifted the global distribution of water so much that the North Pole has drifted by more more than 4 centimetres per year.

Not alarmist, just cool. When I was in grad school we studied we used dInSAR to study groundwater pumping related subsidence. It makes perfect sense that there would be mass redistribution.

  • TroyOPMEnglish
    2·
    1 year ago

    It doesn’t stay in the atmosphere for long – it’ll rain somewhere else and run into the ocean.

    Water is an interesting greenhouse gas. When it is in the atmosphere as vapour, it is a very potent greenhouse gas. But the atmosphere has a load bearing limit – how much water can it hold before clouds form. And clouds, ironically, reflect sunlight away from the earth and back into space (they are white, after all…). So in the end, water in the atmosphere will reach an equilibrium that is related to the temperature of the atmosphere. The hotter the atmosphere, the more vapour it can hold before turning into clouds.

    Largely though, any additional water vapour in the air due to irrigation is trivial compared to the water that evaporates from the ocean surfaces. And global warming is heating the oceans, causing more evaporation, which is a feedback loop. Particularly in the arctic, where ice cover used to reflect sunlight back into space, open water is now absorbing sunlight and reinforcing the feedback loop.

    Irrigation water evaporation is largely a short term climate issue, but locally, once the water runs out, it will be a major problem – fields will turn back into deserts unless water is shipped in.