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If we’re going to find our way out of this climate crisis that we’ve created, we’ll need
radical ideas. And right now, lots of these ideas are aimed at getting our emissions down to zero,
to keep the Earth from getting catastrophically warmer, which would be great. But we also need
to deal with the amount of climate change that’s already locked in. And to do that, we also need
to think big. One consequence we’re already seeing is sea level rise, as glaciers and ice sheets melt
into the ocean. That’s why some scientists are exploring ways to geoengineer glaciers
on a massive scale in the hopes of slowing down the rising water. Geoengineering is the idea of
intentionally manipulating the environment on massive scales. Like, putting giant mirrors in
space to reflect some sunlight away from Earth so things can cool down a bit. Or scattering
little particles throughout the atmosphere to keep some light from getting through. But many of these
ideas are pretty controversial, so the whole thing is more concept than practice, at least for now.
It’s not like we haven’t already been manipulating the climate for centuries by pumping greenhouse
gases into the air and cutting down trees. But tinkering with our one and only home planet on
purpose is not something everyone can get behind. Still, massive problems call for massive proposed
solutions. And one massive problem is melting ice. Water that’s currently locked into ice
in Antarctica and Greenland could lead to over 20 meters of sea level rise if it melts into the sea.
That’s enough sea level rise to cover a six-story building and wash a bunch of islands and coastal
cities straight off the map. So, while it comes with risks, scientists and governments have been
talking about using geoengineering to deal with melting glaciers. And one idea is to keep glacial
ice cold by putting a blanket on it. That’s because, in some glaciers, a lot of the melting
happens at the top, where warmer air touches the ice. And when melting begins, it tends to set up
a vicious cycle: It creates a pool of water, and since water is darker than ice, it absorbs more
sunlight, getting even warmer. And that makes it melt more readily and the cycle continues. Even
after these melted pools drain away or dry up, they can leave behind dark debris that absorbs
more sunlight than the surrounding ice. And once again, that darker area is more likely to warm
up the ice enough that it melts. And that’s why, in Italy and Switzerland, people have literally
covered some glaciers with blankets to reflect sunlight and keep the glaciers from getting too
toasty and melting. Unfortunately, there’s just no way we’re going to put blankets over
all of Greenland and Antarctica. So scientists are thinking about other ways of “blanketing” ice. And
some have come up with a sand-like material that reflects sunlight back into space. In one study,
they tested this out on a pond in Minnesota, and it actually worked! Ice that was treated with
this special “sand” stayed frozen much longer than untreated ice. The sand could be spread by hand,
or using an agricultural seed sower. But even if we’re using sand instead of physical blankets,
covering large parts of Greenland and Antarctica would still be a huge practical challenge. So in
the meantime, some geoengineering research is looking at the other side of glaciers:
the part scraping along the ground. Like rivers, many glaciers drain into the ocean, so fast-moving
glaciers lose ice more quickly than slower ones. And many of the fastest-moving glaciers slide out
to sea on a layer of liquid water. That water can come from the bottom of the glacier if the
ground is warm enough to melt some ice, or if the friction from sliding heats things up. Other
times, water slips under glaciers through cracks. Either way, it basically creates a slip-n-slide
that slides the glacier out to sea. So, if we could just get rid of that water, it might slow
glaciers down like a slip-n-slide without the water. One way we might do this is actually
inspired by the very industry that got us into this mess in the first place: oil. The idea is if
we could drill down into glaciers and extract this water, using very similar technology to what’s
used in oil drilling, we could slow down these glaciers and keep them from draining so quickly
into the ocean. We wouldn’t do this for all of the world’s hundreds of thousands of glaciers, but we
could potentially use this approach to stabilize the ice sheets that are contributing the most to
sea level rise. As with blanketing glaciers, extracting water from underneath enormous ice
sheets comes with a ton of practical challenges, so no one is ready to try this just yet. But if
we do end up drilling a bunch of boreholes in glaciers to drain them, there might be several
ways to use them such as essentially refrigerating the glacier. The idea is this: If we could inject
cold substances into these boreholes, we could potentially freeze any water under the glacier.
This is basically the same idea as draining the glacier, but a different flavor: it would make the
bottom dry and eliminate the slip-n-slide. And just maybe we could even use the same gas that
caused most of the planet’s warming to cool things down. I’m talking about CO2. Now, when you think
of CO2, there’s a good chance you automatically think “warming.” That’s because CO2 in the
atmosphere is famous for trapping heat and making our planet hotter and hotter. But CO2 actually
makes a pretty good refrigerant, or substance that cools things down. In fact, it was even used in
one of the first-ever refrigerators in the 1850s. The way it works is, you need a machine that
can compress CO2 and turn it into a liquid. Then when it comes in contact with a warmer substance,
it absorbs some of that heat and turns back into a gas. There are various gases that can do this, but
the great thing about CO2 is that it’s relatively harmless when it’s not off being a greenhouse gas.
So basically, we’d need to build refrigeration systems that could pump liquid CO2 into glaciers,
then, once it turns back into a gas, liquify it again and send it back into the hole. Obviously
this is not a simple job, nor a one-stop shop to fix everything. But it could end up being one of
the tools in our toolbox. The thing about all of these geoengineering ideas is that we won’t
be putting any of them into practice tomorrow. None of them are feasible yet on a large scale,
and some might just not be possible ever. They all come with enormous technical challenges. But we
can’t just reverse all the climate change we’ve already brought upon ourselves. So ideas like
these give scientists a place to start thinking about what they could realistically change. You’ve
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