• During the past 3 centuries human population has increased
tenfold to 6000 million and fourfold in the 20th century• Cattle population increased to 1400 million (one cow/family);by a factor of 4 during the past century• Urbanisation grew more than tenfold in the past century;
almost half of the people live in cities and megacities• Industrial output increased 40 times during the past century;
energy use 16 times• Almost 50 % of the land surface has been transformed byhuman action• Water use increased 9 fold during the past century to 800 m3
per capita; 65 % for irrigation, 25 % industry, ~10 %households

• Human appropriation of terrestrial net primary productivity ~ 30%,
but with large uncertainties, Vitousek et al., Science, 494, 1997,
Rojstaczer et al., Science, 2549, 2001
• Fish catch increased 40 times• The release of SO2 (160 Tg/year) by coal and oil burning is at least
twice the sum of all natural emissions; over land the increase has
been 7 fold, causing acid rain, health effects, poor visibility, andclimate changes due to sulfate aerosols• Releases of NO to the atmosphere from fossil fuel and biomassburning is larger than its natural inputs, causing high surface ozone
levels over extensive regions of the globe• Several climatically important ”greenhouse gases” havesubstantially increased in the atmosphere, eg. CO2 by 30 %, CH4
by more than 100 %.

•Humanity is also responsible for the presence of many
toxic substances in the environment and even somewhich are not toxic at all, but which have, nervetheless,
led to the ozone hole.
•Among the „greenhouse gases“ are also the almost
inert CFC (chlorofluorocarbon) gases. However, theirphotochemical breakdown in the stratosphere gives rise
to highly reactive chlorine atoms, which destroy ozone
by catalytic reactions. As a consequence UV-B radiationfrom the sun increases, leading for instance to enhanced
risk of skin cancer.

Vitousek (1994)

Man the Eroder•Man-caused erosion (crop tillage, land conversion
for grazing and construction): 15 times naturalerosion•At current rate anthropogenic soil erosion would fill
the Grand Canyon in 50 years.
According to Wilkinson (Geology) March 2005.

•E.O. Wilson “Before humans existed, the species
extinction rate was (very roughly) one species per million
species per year. Estimates for current species extinction
rates range form 100 to 10,000 times that, but most hover
close to 1,000 times prehuman levels (0.1% per year)•In an article titled “Humans as the World‘s Greatest
Evolutionary Force“, Palumbi (Science, 7 September2001) states that mankind also effects evolutionarychange in other species, especially in commercially
important, pest, and disease organisms, throughantibiotica and pesticides. This accelerated evolutioncosts at least $33 billion to $50 billion a year in theUnited States.

Since the beginning of the 19thCentury, by its own growing activities,Mankind opened a new geological era:
the Anthropocene“The balance of evidence suggests a discernable human influenceon global climate“ (IPCC, 1995)„There is new and stronger evidence that most of the warming
observed over the last 50 years is attributable to humanactivities“ (IPCC, 2001)
Average Global Temperature Rise: 1.4 – 5.8 °C from 1999 to2100 (includes cooling effects by sulfate aerosol)Sea level rise: + 9 – 88 cm until 2100.
+ 0.5 – 10 m until ~ 3000.
Redistribution of precipitation
Enhanced risk for extreme weather (flooding, desertification)?
Increase in heat waves in Europe, as in the summer of 2003?
Too rapid climate changes, so that ecosystems cannot adapt.

Stabilisation of Atmospheric Concentrations. Reductions in the human-madeemission required to stabilise concentrations at current levels
Greenhouse Gas

Reduction Required

Carbon Dioxide> 60%Methane(achieved, but long term stabilisationis uncertain for instance by thawing ofpermafrost)

Nitrous Oxide

70-80%

CFC-11achieved

CFC-12achieved

CO2

Climate of the polar regions is most sensitive
Model calculated temperature charges for a doubling of atmospheric CO2 content

•„New studies indicate that the Arctic oceans ice cover isabout 40% thinner than 20-40 years ago“. Levy, Physics
Today, January 2000.
•There is dramatic climate change happening in theArctic, about 2-3 times the pace for the whole globe:
Robert Corell, Chairman of the Arctic Climate Impact
Assessment, November 2004.

Nature, Vol. 437, p. 681, 2005

Richard B. Alley: Abrupt climate change
Scientific American, November 2004

The Composition of Aerosol
AshDustBlack carbon

7%

11%

Organics

MISS 2%17%

Sea-salt & NO3 11%2%

K

12%
26%

NH+4SO4Shows the relative contribution of the various chemical species to the aerosol
optical properties at visible wavelengths (Satheesh et al., 2000; Lelieveld et al.,2000)