The Anthropocene and
Beyond
Our last lecture (for now!).
Here’s my email address again;
[email protected]
If you want to talk about what
we’ve covered/not covered, need
to vent steam, bile, etc., contact
me. I’ll gladly talk to other groups
if you think that would be useful.
Water is the new oil;
Domestic water use
Poor water quality
Water depletion
 Through the Holocene, increasing
population has driven greater demand
for natural resources, and improving
technology has provided the means to
exploit those resources. We have
radically changed the appearance and
behaviour of the Earth and its
biophysical systems. We have done
so with little regard for outcome.
Ultimately it’s all about population
growth.
Global and regional population projections
Environmental and economic indicators
 Some have proposed that over the last
couple of centuries, our influence has
created a world with no precedent, and
that we should recognize this with a new
designation – the Anthropocene ( Paul
Crutzen).
 There is no agreement as to when this new
‘age’ started. A reasonable boundary might
be 1850, when the Industrial Revolution
really got going, but others suggest 1950.
The major changes;
 1. the removal and fragmentation of
natural habitat. This is not recent and not
confined to the tropical rainforest.
Deforestation changes local to regional
climate and hydrology. It changes Earth
albedo and contributes to the
Greenhouse Effect.
 2. the creation of new/modified habitats
and systems – agroecosystems, urban
and suburban landscapes, etc.
Land-use changes over the last 300 years;
Forest fragmentation in southern Ontario. Prior to
European settlement about 85% of SO was forest
covered.
Terraces and paddy rice
Copper mine, Bingham, Utah
Man-made desert, Inner Mongolia
Coastal transformation, Dubai
Urbanization;
Currently about 50% of global population
lives in cities. That proportion is rising
rapidly particularly in developing countries.
Big cities generate their own problems of
infrastructure (power, water, sewage, food,
transport, etc.) as well as contribute to
atmospheric chemistry and global
warming.
Projected urbanization in China and India
 3. globalization of plants and animals and
disease. The first will be one of the causes
for a massive loss of biodiversity (‘the Sixth
Extinction’). Epidemic diseases have
become pandemic and the potential for
more, new and catastrophic outbreaks
remains high despite our vigilance.
 4. environmental degradation – a product of
habitat removal and inappropriate land-use
(overcultivation and overgrazing, overuse of
water and fertilizer, inadequate waste
treatment, etc.).
Remember that we have no
handle on how many species
there are in the world. It’s related
to size. We know how many big
species there are ( approx. 9500
species of birds, about 4700
species of mammals, etc.).
Insects? 1-30 million
Bacteria? 10 million to 1 billion
 Settlement of the
Midwest from early 19C.
 Numbers of PP at
settlement – 3-5 billion.
 Last shot in the wild –
1901.
 Last zoo survivor –
1941.
Buffalo numbers prior to European settlement – 50
to 60 million. Less than 100 in the wild by late
1880s.
Disaster in progress – shark finning
 5. changes in atmospheric chemistry
(acid deposition, ozone depletion, global
warming, etc.).
 Global warming is the first indicator of the
scope of human impact.
 Let’s take a brief look at it and its impacts.
Global Warming
 Global warming appears to be largely a
product of the build up of greenhouse
gasses, an anthropogenic phenomenon,
despite the denials of a noisy few (and
some governments!).
 The main gasses are water vapour, CO2,
CH4 ,N2O and O3. They act by selectively
absorbing longwave (infrared) radiation
and thus retard the return of that radiation
back into space.
CO2 through time
 Anthropogenic impacts in the
atmosphere do not all lead to warming.
 Increasing Earth albedo should dampen
greenhouse warming as should the large
amount of atmospheric aerosol/particulate
matter derived from agriculture, industry,
transportation, etc.
 The extra CO2 comes from fossil fuel
combustion and the removal and burning
of forest.
 Methane (CH4) comes naturally from
wetlands. Anthropogenic sources include
domesticated livestock, rice paddies and
decaying matter in landfills.
 Nitrous oxide (N2O) comes naturally from
microbial processes in soil. Biomass
burning is an important anthropogenic
contribution.
Changes in the concentration of some
greenhouse gasses;
Implications of global warming;
 1. although increasing temperature is the
most obvious consequence, other likely
impacts include increasing moisture
deficits, increasing storminess, higher
climatic variability (heat waves, droughts,
etc.).
 2. melting of permafrost and release of
carbon and methane
 3. increasing pressure on the biosphere
e.g. Inability of species to migrate/shift to
compensate
 4. changes in the distribution and
ecology of disease (virulence, etc.).
Expansion of tropical diseases into higher
latitudes.
 5. increasing sea level. The result of
warmer oceans and melting ice.
 6. increasing acidification of the
oceans. Absorption of CO2 by oceans
leads to carbonic acid formation, lower pH
and problems for plankton, molluscs, etc.
Sea level rise in northwest Europe
Bangladesh
What of our future?
 Our planet has a natural life
expectancy of about 5 billion years. Is
its future rosy or bleak?
 Our immediate future (the next few
decades) looks grim – unless we do
something about what’s going on
NOW!
Let’s consider our immediate future.
 Most of us recognize that our world is in
crisis and that those crises mirror those
generated by most earlier societies. How
and why do complex, sophisticated and
creative civilizations fail?
 Earlier we saw the coup de grace for most
societies was an inability to live
sustainably and a failure to adjust to
even modest climatic shifts.
 Sound familiar?
 The threats facing us are both
anthropogenic and natural.
 Anthropogenic risks include the
obvious ones;
 Overpopulation
 Environmental degradation
 Resource depletion
 Global warming
 Nuclear holocaust
As well as those of more recent
and less clearly understood risks
such as;
Artificial intelligence
Biotechnology/bioterrorism
Cyberterrorism
Failure of global governance
Non-equitable resource allocation.
 Natural threats include;
 Disease pandemics
 Supervolcanic eruption
 Changes in Earth-Sun geometry
 Geo-dynamic changes (PT)
 Asteroid impact
 Supernovae and gamma radiation
bursts
 Solar evolution
 Extraterrestrial invasion
 Without change we drift into a world of
decreasing sustainability, of too many
people and too few resources, and of
increasing competition for those resources.
What could our future look like?
Most scenarios are dystopian.
Try these;
1988
2007
1985
2013
2005-8
1968
1973
1985
1996
NO !!!!!!
If we leave, where do we go?
Living in space
Life on Mars
One lightyear = 9.5 trillion kilometers
What’s in the middle and distant future?
In 2 billion years time the Earth will have
become a desert. Increasing heat from the
sun will drive off much of the Earth’s
hydrosphere. Life will be microbial (again!)
with extremophiles persisting mostly
underground.
In the end, the sun, burning helium not
hydrogen, will become a red dwarf and
engulf the inner planets.
But there’s a bright side.
Back to stardust! The
ultimate in recycling!
Thanks for inviting me. I’ve
enjoyed myself enormously. I
hope that you did too.