John Baez
October 13, 2006
Zooming Out in Time
How can we detect and understand oncoming crises in time to avert
them? Sometimes we must "zoom out": expand our
perspective and find similar situations in the distant past.
A good example is climate change. What can a few degrees of warming
do? To answer this, we need to know some
history: how the Earth's climate has changed over the last 65 million years.
Click here to see the slides of this talk:
The version without hyperlinks is a bit prettier. The version
with hyperlinks takes you to information about each picture.
You can also hear the talk:
The Long Now Foundation
was established in 01996 to develop
the Clock and Library
projects, as well as to become the seed of a very long term cultural
institution. They hope to provide counterpoint to today's "faster/cheaper"
mind set and promote "slower/better" thinking. They hope to creatively
foster responsibility in the framework of the next 10,000 years.
Here's Stewart Brand's
summary
of the talk:
The graphs we see these days, John Baez began, all look vertical — carbon
burning shooting up, CO2 in the air shooting up, global temperature
shooting up, and population still shooting up. How can we understand what
really going on? "It's like trying to understand geology while you're hanging
by your fingernails on a cliff, scared to death. You think all geology is vertical."
So, zoom out for some perspective. An Earth temperature graph for the last
18,000 years shows that we've built a false sense of security from 10,000
years of unusually stable climate. Even so, a "little dent" in the graph of a
drop of only 1 degree Celsius put Europe in a what's called "the little ice
age" from 1555 to 1850. It ended just when industrial activity took off,
which raises the question whether it was us that ended it.
Nobel laureate atmospheric scientist Paul Crutzen suggests that the current
geological era should be called the "Anthropocene," because it is increasingly
dominated by human-caused effects. Baez noted that oil companies now can send
their tankers through a Northwest Passage that they may have created, since
it is fossil fuel burning that raised the CO2 that raised the
summer temperatures in the Arctic that melts the polar ice away from the land.
Zoom out further still to the last 65 million years. The temperature
graph show several major features. One is the rapid (every 100,000 years)
wide swings of major ice ages. When they began, 1.35 million years ago, is
when humans mastered fire. But almost all of the period was much warmer than
now, with ferns growing in Antarctica. "Now it's cold. What's wrong with a
little warming?" Baez asked.
The problem is that the current warming is happening too fast. Studies of
1,500 species in Europe show that their ranges are moving north at 6
kilometers a decade, but the climate zones are moving north at 40 kilometers
a decade, faster than they can keep up. The global temperature is now the
hottest it's been in 120,000 years. One degree Celsius more and it will
be the hottest since 1.35 million years ago, before the ice ages. Baez
suggested that the Anthropocene may be characterized mainly by species
such as cockroaches and raccoons who accommodate well to humans. Coyotes are
now turning up in Manhattan and Los Angeles. There are expectations that
we could lose one-third of all species by mid-century, from climate change
and other human causes.
Okay, to think about major extinctions, zoom out again. Over the last
550 million years there have been over a dozen mass extinctions, the
worst being the Permian-Triassic extinction 250 million years ago, when
over half of all life disappeared. The cause is still uncertain, but one
candidate is the methane clathrates ("methane ice") on the ocean floor.
Since methane is a far worse greenhouse gas than carbon dioxide, massive
"burps" of the gas could have led to sudden drastic global heating and
thus the huge die-off of species. Naturally the methane clathrates are
being studied as an industrial fuel for when the oil runs out in this
century, "which could make our effect on global warming 10,000 times worse,"
Baez noted.
"Zooming out in time is how I calm myself down after reading the newspapers,"
Baez concluded. "A mass extinction is a sad thing, but life does bounce
back, and it gets more interesting each time. We probably won't kill off all
life on Earth. But even if we do, there are a hundred billion stars in our
galaxy, and ten billion galaxies in the observable universe."
– Stewart Brand
The further back I look, the further forward I can see.
- Winston Churchill
He who cannot draw on 3,000 years is living hand to mouth.
- Goethe
© 2006 John Baez - except for images (the above image was
produced by The
Long Now Foundation)
baez@math.removethis.ucr.andthis.edu