introduction to environmental science and natural resourcesdrivers indirect drivers ecosystem...
TRANSCRIPT
UAU102F Fall
Throstur Thorsteinsson ([email protected]) 1
Throstur Thorsteinsson
Human Domination of the Earth’s ecosystems
Taking stock - current state of domination
The doomslayers vs. the doomsayers
o Julian Simon and Bjorn Lomborg,
vs. Meadows, Ehrlich and others
Our role!
Name 3 reasons why everything is going to hell,
and 3 why we should be optimistic.
Population growth
continues to increase.
Combined with GDP
growth implies increase
in resource consumption.
World population
7,347,356,000
28 August 2016http://www.census.gov/popclock/
http://esa.un.org/unpd/wpp/Publications/Files/
Key_Findings_WPP_2015.pdf
Uneven distribution GWP has grown 8x since 1950
Implications for the environment and natural
resources??
Been equitable? QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.
UAU102F Fall
Throstur Thorsteinsson ([email protected]) 2
Sao Paolo, Brazil
http://www.wackyarchives.com/offbeat/rich-vs-poor-in-the-3rd-world.html
Myths
Most environmental
degradation is done by
the poor?
Poverty reduction leads
to environmental
degradation?
Population growth
necessarily leads to env.
degradation?
The poor are too poor to
invest in env?
Poor people lack
technical knowledge for
resource management?
The champagne glass
Largest assessment of the health of the
world’s ecosystems
Completed in 2005 http://www.millenniumassessment.org/en/index.html
o Experts and Review Process
• Prepared by 1360 experts from 95 countries
• 80-person independent board of review editors
• Review comments from 850 experts and governments
o Governance
• Called for by UN Secretary General in 2000
• Authorized by governments through 4 conventions
• Partnership of UN agencies, conventions, business, non-governmental organizations with a multi-stakeholder board of directors
The MEA framework identified important linkages between
‘Ecosystem Services’ and human well-being
UAU102F Fall
Throstur Thorsteinsson ([email protected]) 3
Direct
Drivers
Indirect
Drivers
Ecosystem
Services
Human
Well-being
Direct Drivers of Change Changes in land use Species introduction or removal Technology adaptation and use
External inputs (e.g., irrigation) Resource consumption Climate change Natural physical and biological
drivers (e.g., volcanoes)
Indirect Drivers of Change Demographic Economic (globalization, trade,
market and policy framework)
Sociopolitical (governance and institutional framework)
Science and Technology Cultural and Religious
Human Well-being and
Poverty Reduction Basic material for a good life Health
Good Social Relations Security Freedom of choice and action
o Over the past 50 years, humans have changed ecosystems more rapidly and extensively than in any comparable period of time in human history, largely to meet rapidly growing demands for food, fresh water, timber, fiber and fuel.
o The changes that have been made to ecosystems have contributed to substantial net gains in human well-being and economic development, but …
• these gains have been achieved at growing costs in the
form of the degradation of many ecosystem services,
increased risks of nonlinear changes, and the exacerbation
of poverty for some groups of people.
• The degradation of ecosystem services could grow
significantly …
More land was converted to cropland in the 30 years after 1950 than in the 150 years between
1700 and 1850
20% of the world’s coral reefs were lost and 20% degraded in the last several decades
35% of mangrove* area has been lost in the last several decades
Amount of water in reservoirs quadrupled since 1960
Withdrawals from rivers and lakes doubled since 1960
o 5 to possibly 25% of global freshwater use exceeds long-term
accessible supplies (low to medium certainty)
o 15 - 35% of irrigation withdrawals exceed supply rates and are
therefore unsustainable (low to medium certainty)
UAU102F Fall
Throstur Thorsteinsson ([email protected]) 4
Natural hazard regulation
o The capacity of ecosystems to buffer from extreme events has been reduced through loss of wetlands, forests, mangroves
o People increasingly occupying regions exposed to extreme events
o Degradation tends to lead to the
loss of non-marketed benefits from
ecosystems
o The economic value of these
benefits is often high and
sometimes higher than the
marketed benefits
Timber and fuel-wood
generally accounted for
less than a third of total
economic value of forests.
o Over the past 50 years, humans have changed ecosystems more
rapidly and extensively than in any comparable period of time in human
history
o This has resulted in a substantial and largely irreversible loss in the
diversity of life on Earth
o Will have drastic impacts on
human welfare
NASA black marble
Vitousek 1997
UAU102F Fall
Throstur Thorsteinsson ([email protected]) 5
Human alteration of Earth is substantial and growing.
Between one-third and one-half of the land surface has been
transformed by human action; the carbon dioxide concentration in the
atmosphere has increased by nearly 30 percent since the beginning of
the Industrial Revolution; more atmospheric nitrogen is fixed by
humanity than by all natural terrestrial sources combined; more than
half of all accessible surface fresh water is put to use by humanity;
and about one-quarter of the bird species on Earth have been driven
to extinction.
By these and other standards, it is clear that we live on a human
dominated planet.
Human Domination of Earth’s EcosystemsMore land was converted to cropland
in the 30 years after 1950 than in the 150 years between 1700 and 1850.
Alters structure and functioning of ecosystems
o 10-15% occupied by row-crop
agriculture
o 6-8% converted to pastureland
o Forests and woodland cleared
Yunnan, China
Jordan
Cultivated Systems in 2000 cover 25% of Earth’s terrestrial surface
(Defined as areas where at least 30% of the landscape is in croplands, shifting cultivation, confined livestock production, or freshwater aquaculture)
Vitousek et al. 1986
Examined the impact on the biosphere by calculating
the NPP (Net primary production) that humans have
appropriated
Seminal study
o NPP: is the amount of energy left after subtracting the
respiration of primary producers from the total amount of
energy that is fixed biologically through photosynthesis
o Total food resource on the earth
Global oceanic
and terrestrial
photoautotroph
abundance,
from September
1997 to August
2000. As an
estimate of
autotroph*
biomass, it is
only a rough
indicator of
primary
production
potential, and
not an actual
estimate of it.
Conclusion
appropriated by humans:
40% of terrestrial NPP
25% of global NPP
UAU102F Fall
Throstur Thorsteinsson ([email protected]) 6
o The distribution of species on
Earth is becoming more
homogenous
o Humans have increased the
species extinction rate by as
much as 1,000 times over
background rates typical over the
planet’s history (medium
certainty)
o 10–30% of mammal, bird, and
amphibian species are currently
threatened with extinction
(medium to high certainty)
Coastal wetlands
have been severely
altered
o 50% of mangroves
transformed, 35% lost
o 20% coral reefs lost
25% of commercially exploited marine fish stocks are overharvested (high certainty, MEA)
44% at the limit of exploitation
28% already collapsed
Collective collapse within 40 years if BAU continues (Worm, 2006)
Serious impact from fishing gear
Implications from discards
Increase in the frequency of algal blooms
o Temperature, nutrients, salinity
Changes in the distribution of species
o Possibly due to climate change
• Acidification, temperature change
Human populationSize Resource use
Human enterprisesAgriculture Industry Recreation International
Land transformationLand clearing
GrazingForestry
Intensification
Global
biogeochemistryCarbon
Sulfur
Nitrogen
Water
Biotic additions and losses
HuntingFishingInvasionCutting
Climate changeEnhanced greenhouse
AerosolsLandcover
Loss of biological
diversitySpecies
EcosystemsPopulations below VPS
Vitousek 1997
UAU102F Fall
Throstur Thorsteinsson ([email protected]) 7
Since 1960
o Flows of biologically available
nitrogen in terrestrial ecosystems doubled
o Flows of phosphorus tripled
> 50% of all the synthetic nitrogen
fertilizer ever used has been used since
1985
Human-produced Reactive Nitrogen
Humans produce as much biologically available N as all natural pathways and this
may grow a further 65% by 2050
Primary resource for photosynthesis
Anthropogenic emissions from:
o Burning fossil fuels
o Mining
o Land conversion
o Industrial processes
Carbon Emissions from
use of fossil fuels
increased since 1950
from 1.63 to 7.57 billion
tons of carbon
CO2 Concentration 404
parts per million
(http://co2.earth)
Do we have a problem?
Average Global Temperature in 2006 14.6°C, expected to increase from 1.4° – 6°C in 100 years
Recent years the warmest years on record
Glaciers melting, profound impact on ecosystems
To meet increasing demand:
o Altered river systems, 2% of rivers in USA run unimpeded
o Withdrawal so extensive in many rivers little water reaches the ocean (a problem?)
o Depletion of aquifers (groundwater)
Serious impact from dams
Dilution of waste - transportation
UAU102F Fall
Throstur Thorsteinsson ([email protected]) 8
Green, not affected
Yellow, moderately affected
Red, strongly affected
Humans appropriate
30% of accessible
Renewable Fresh
Water Sources (RFWS)
Humans appropriate
23% of all RFWS
Total runoff
appropriated 54%
The Doomsayers
o The environment is going to hell and human life is doomed to only
get worse.
o Malthus in Principles of Population
o Ehrlich and Ehrlich in the Population Bomb
o Yes - we are running out of resources, the air is bad, the water
worse……
The Doomslayers:
o Julian Simon and Bjorn Lombok - the claims of the doomsayers are false, based on faulty data
o Humans are better off than before
o Resources are not running out - people create resources and will simply shift to something new
o New technologies will continue to reduce pollution …
o The world is not coming to an end!
o Food production has more than
doubled since 1960
o Food production per capita has grown
o Food price has fallen
Desert irrigation in Jordan
Contributions of agriculture
o Agricultural labor force accounts for 22% of the world’s population and half the world’s total labor force
o Agriculture accounts for 24% of GDP in low income developing countries
Market value of ecosystem-service industries
o Food production: $980 billion per year
o Timber industry: $400 billion per year
o Marine fisheries: $80 billion per year
o Marine aquaculture: $57 billion per year
o Recreational hunting and fishing: >$75 billion per year in the United States alone
UAU102F Fall
Throstur Thorsteinsson ([email protected]) 9
o Approximately 60% (15 out of 24) of the ecosystem services
evaluated in the MEA assessment are being degraded or used unsustainably
o The degradation of ecosystem services often causes significant
harm to human well-being and represents a loss of a natural asset or wealth of a country
o Not to mention impact on poverty
Truth somewhere in between
Your role to prevent the doomsayers predictions!
– to do so we need to know the extent and nature of the
degradation in addition to the reasons.