The strangest summer in recorded history - David Biello
It’s April 10th, 1815,
and in just a few moments,
the sun is going to disappear.
On an island in present-day Indonesia,
Mount Tambora erupts with a boom that can
be heard over 2,000 kilometers away.
Sulfurous plumes of steam and ash billow
thousands of meters into the sky,
forming dark storm clouds
of soot and lightning.
This eruption will go down as the
largest in recorded history,
but, at this point,
its impact is only just beginning.
Ascending high into the atmosphere,
Tambora’s emissions spread
across the globe,
blotting out the sun
for almost an entire year.
The hazy skies and cold weather of 1816
wreak havoc on agriculture,
leading to famines all across
the Northern Hemisphere.
Nations struggle with epidemics,
and artists craft bleak tributes
to these seemingly apocalyptic times.
This was the year without summer—
literally one of the darkest periods
in human history.
So why are some modern researchers
looking for ways to repeat it?
Obviously, no one wants to replicate
this period’s famine and despair.
But some scientists are interested in
using sulfurous haze to block out the sun,
and hopefully,
slow the effects of global warming.
This is one of many proposals
in the realm of geoengineering—
a class of deliberate, large-scale
interventions in Earth’s natural systems
intended to help restrain climate change.
Different geoengineering schemes
intervene in different systems.
Any plans to cool the planet by blocking
the amount of sunlight reaching the earth
would fall in the category
of solar radiation management.
Some of these proposals
are massive in scale,
such as suggestions to create
a helpful version of volcanic plumes
or build a giant sunshade
in Earth’s orbit.
Others are more limited, focusing
on enhancing natural cooling systems.
For example, researchers might
enlarge marine clouds
or make Earth reflect more sunlight
by building huge swaths of white surfaces.
Many of these plans sound more
than a little strange.
But there’s reason to believe
they might work,
not least because of natural events
like the eruption of Tambora.
Scientists know that volcanic eruptions
have periodically cooled the climate.
Both the Pinatubo eruption in 1991
and 1883′s blast of Krakatoa reduced
global average temperatures
by at least half-a-degree Celsius
for up to a year.
These cooling effects are
global and fast acting—
but they're also incredibly risky.
The Earth is a chaotic system
where even the smallest changes
can create countless
unpredictable ripple effects.
We know that cooling temperatures
impacts precipitation,
extreme weather,
and other climate phenomena,
but it’s difficult for even the most
advanced computer models
to predict how or where
these consequences will occur.
One country’s solar radiation management
might be another country’s
unnatural disaster,
causing extreme weather or crop failures
like those following Tambora’s eruption.
And even if these schemes did
safely cool the planet,
solar radiation management
doesn’t address the greenhouse gases
that are causing global warming.
These solutions are just highly
experimental band-aids
that the world would have to endure
for at least a few decades
while we work on actually removing
CO2 from the air.
And if we pulled that band-aid
off prematurely,
global temperatures could rapidly rebound,
causing a period of intense super warming.
For these reasons and more
solar radiation management is risky.
Today, researchers are running
small-scale experiments,
such as enhancing marine clouds
to protect the Great Barrier Reef
from further heating and bleaching.
And most scientists agree that we should
pursue ways to cut emissions
and remove atmospheric CO2
first and foremost.
However, there are reasons to keep
studying these more aggressive approaches.
Desperate times call for desperate
measures, and in the future,
geoengineering might be
civilization’s last resort.
Furthermore, some of these plans would
be shockingly easy to execute
by some rogue actor with enough cash.
So we’ll want to be prepared
if someone starts geoengineering
without governmental approval.
But perhaps the most important reason to
investigate the impacts of geoengineering
is that people are already making large
scale interventions in the atmosphere.
In many ways, climate change
is an unintended geoengineering project
fueled by the emissions
generated from centuries
of burning fossil fuels.
And unless we take action
to curb emissions
and draw CO2 out of the atmosphere soon,
summer may never be the same again.
