Download Main contributing factors to changes of Earth´s climate

Main contributing factors to changes of
Earth´s climate
- change of Earth’s orbit
- greenhouse effect
- thermal pollution
- chemical pollution
- (de)forestation
- volcanic activities
- change of Earth’s magnetism
- other
History of greenhouse effect
1827. Jean B. J. Fourier:
«Light find less resistance in penetrating the air, than in repassing
into the air when converted to heat.»
1860. John Tyndall:
showed that CO2 and water vapor both absorb and emit infrared
radiation.
1896. Svante Arrhenius:
showed by calculation in a simplified model that a 50% increase of
CO2 would warm the Earth´s surface by 3 oC.
1914.-1938. Milutin Milanković:
showed by calculation that a quasiperiodic change of Earth´s orbit
around Sun causes the interchange of global warming and global
cooling.
1938. Stewart Callender:
in a simple model predicted that projected increase of
atmospheric CO2 would increase the temperature by about 0.3 oC
per century.
1960.-1980. actual global cooling:
provided a scientific argument against attribution of early 20th
century warming to CO2 increase.
1982. US NAS
computed based prediction that doubling of CO2 atmospheric
concentration would lead to increase of temperature of 1.5-4.5 oC.
2007. IPCC 2007
computed based prediction increase of CO2 atmospheric
concentration in 21st century would lead to increase of
temperature of 1.1-6.4 oC.
CO2 concentration in atmosphere
before 35 000 000 years 2,000 ppm
before 20 000 years
200 ppm
1807.
280 ppm
1858.
288 ppm
1914.
300 ppm
1950.
310 ppm
1970.
325 ppm
1985.
345 ppm
2007.
380 ppm
GREENHOUSE GASES
CO2
CH4
FClCH
O3
N2O
Other
OCEANS – ATMOSPHERIC CO2 SINK
Volcanoes bring CO2 and volcanic rocks from deep
inside the Earth to the surface.
Rainfall picks up some CO2 from the atmosphere
making a weak acid. That acid breaks rocks down
and particles of rock and CO2 are washed to the
ocean.
Chemical reaction stores CO2:
rock (CaSiO3) + CO2
sediments at ocean floor (CaCO3 + SiO2)
The rate at which CO2 is removed from the atmosphere
increases with increasing temperature. Therefore,
greenhouse effect acts as thermostat.
During the last 8,000 years human activity was
introducing additional CO2 into atmosphere.
Ocean absorbs 50% of yearly CO2 production.
Lifetime of atmospheric CO2 is about 100 years (before
being absorbed by oceans, soil and biosphere)!
CO2 Cycle:
volcanoes atmosphere ocean sediments
Earth´s interior volcanoes .....
«JUMPING» CLIMATE
CLIMATE OVER THE PAST 100,000 YEARS
Over the past 100,000 years there were only two vaguely
stable periods of climate:
- the first was when the ice age was coldest, about
20,000 years ago, during period of a few thousand
years, and
- the second is the recent period over the last 10,000
years.
But for the most of the last 100,000 years, a «jumping»
climate has been the rule, not the exception. Slow
cooling has been followed by abrupt cooling, centuries
old, and then abrupt warming, with the abrupt warming
generally about 1,500 years apart, although with much
variability.
At the abrupt jumps, the climate often flickered
between warm and cold for a few years at the
time before settling down.
The best known abrupt climate change, the
Younger Dryas event 11,500 years ago, when
Greenland warmed about 8 oC in a decade.
The history of this climatic «craziness» is
written down in the ice of Greenland and
Antarctic, in cave formations, ocean and lake
sediments and other places. This million-year
archive provides year-by-year records of air and
water temperature, ice sheets, storms, oceans
etc.
The current stable climate interval is
among the longest in the record of global
climate!
Nature is thus likely to end our friendly
climate, perhaps quite soon.
In such a situation one should be careful
not to provoke it!
EARTH IS A SENSITIVE
DYNAMIC «BEING»,
UNDERGOING CONTINUOUS
CHANGES!
CONCLUSIONS:
1.Climate in the past has been wildly variable,
with larger and faster changes than anything
humans have ever faced during last five
thousand years
2. Climate can be rather stable during some
times, but when the climate is «pushed» or
forced to change, it often jumps suddenly to
very different conditions.
3. Small «pushes» have caused large changes
because many processes in the Earth´s system
amplify the pushes
(similar to sensitive dependence of
deterministic chaos for nonlinear systems).
Greenhouse gases have probably been
important amplifiers.
The great ice sheets that grew to cover much of
Europe and North America only 20,000 years
ago were responding to changes in the Earth´s
planetary orbit.
4. There is remarkable evidence for «jumping»
climates, which have been especially prominent
during coolings and warmings of the orbitally
driven ice ages.
AND SUCH SITUATION IS ABOUT NOW!
IPCC
(Intergovernmental Panel on Climate
Change)
Previous IPCC predictions:
from 1990. onwards global temperature
would rise by between 0.15 oC and 0.3 oC
per decade.
The actual increase after 1990.:
0.2 0C per decade
fits the initial prediction.
IPCC Report (2007):
With over 90% probability («very likely») recent
temperature increases are driven by human
activities.
Estimate of CO2-doubling response:
2.0-4.5 oC mean temperature rise resulting from
doubling of CO2 level.
Prediction for temperature increase in 21st century:
1.1-6.4 oC.
Predictions of rise of sea level in 21st century :
between 19 cm and 58 cm.
HOW REALISTIC ARE MATHEMATICAL
MODELS OF GLOBAL CLIMATE?
To predict future climate it is necessary to develop mathematical
model of physical processes in the coupled system of atmosphere,
oceans, ice sheets, biosphere, human activities etc.
Because of extreme complexity, only very simplified models are
available what seriously limits the reliability of model predictions.
This was shown many times by inability of climatic models to
predict many known climatic changes from the past, starting the
model earlier in the past and seeing whether the model can
«predict» the things that we know have happened.
Therefore, science can not give fully reliable prediction for future
climate, but only more or less probable outcomes (it is even
uncertain how large is the probability).
Much more research is needed!
NATURE (2007) What we don´t know
about climate change
Report from IPCC (Intergovernmental Panel on Climate
Change) (2007) has a finely calibrate lexicon of
certainty: «virtually certain», «very likely», «more likely
than not» when assigning the probability of climate
effects of human activities. Some conclusions remain
more uncertain than the others.
Perhaps most critically, researchers know relatively
little feedback effects that might enhance- or weaken –
the pace and effects of climate change. The complex
flow of carbon between soils, plants, the oceans and
the atmosphere is still being investigated.
Key sticking points include the inability of global
climate models to produce the amount of sea-level
rise observed over the past couple of decades.
IPCC Report gives first forecasts how changing
climate might affect particular regions of the world,
but improved analyses that incorporate clouds,
snow and ice must be developed.
Extreme weather is another example of the
remaining uncertainties.
Improving the models requires better data. Gaps and
errors in observation are attributable to many
causes.
Caution is necessary in interpreting the IPPC data!
NATURE 419(2002) K.Lambeck et al. Links between climate and
sea levels for the past three million years
The major sea-level cycles occur at intervals of about 100,000
years over the past about 800,000 years, with maximum
amplitude of 120-140 m.
NATURE 445 (2007) G.J. Bowen, When the world turned cold
Before 34 million years, Antarctica has been a lush, green
continent for several tens of millions of years.
Then, in a period of 300.000 years temperature dropped by about
8 oC and CO2 concentration dropped several times from its initial
value of about 2,000 ppm to about few hundred ppm. Ice sheets
grew over most of Antarctica.
NATURE, 446 (2007). S. Bain et al. Effect of natural iron
fertilization on carbon sequestration in the Southern Ocean
Iron concentration in surface waters plays important role on the
uptake of carbon in oceans and may have more significant effect
on atmospheric CO2 concentration than previously thought.
NATURE, 446 (2007) Q. Shiermeier, The new face of Arctic
How the Arctic might change in 2027.
- The Arctic Ocean remains ice-free in September.
- All known Russian offshore oil and gas deposits are
exploited commercially.
- Offshore oil and gas resources unknown today are being
extensively developed.
- Oil tankers and container ships sail the Northeast passage.
NATURE, 426 (2003) Q. Shiermeier, Climate study highlights
inadequacy of emission cuts
The Kyoto Protocol calls for average cuts of 5% by 2012.
German Advisory Council on Global Change concludes that
global CO2 emissions would need to be curbed by 45-60% by
2050 compared with 1990 levels.
NATURE, 448 (2007) P. Pilewskie, Aerosols heat up
Solid particles suspended in atmosphere have long played
second fiddle to greenhouse gases as agents of climate
change. A study of atmospheric heating over the Indian
ocean could provoke a rethink.
SCIENCE, 286 (1999) J.P. Severinghaus, Abrupt climate
change at the end of last glacial period
Greenland warmed 9 oC (6-12 oC) abruptly over a period of
several decades, beginning 14,672 years ago.
NATURE, 448 (2007) V. Ramanathan et al. Warming trends in
Asia amplified by brown cloud solar absorption
We suggest that atmospheric brown clouds contribute as
much as the recent increase in anthropogenic greenhouse
gases to regional lower atmospheric warming trends. We
propose that the combined warming trend of 0.25 oC per
decade may be sufficient to account for the observed retreat
of the Himalayan glaciers.
NATURE, 448 (2007) N. Stafford The other greenhouse effect
Commercial greenhouses contain 700 ppm or more of CO2 .
Rising CO2 concentration increases crop yields but decreases
nutritional quality.
NATURE, 404 (2000) C.S. Hvidberg, When Greenlad ice melts
130,000 to 110,000 years ago the climate was warmer than
today, and the sea level was six meters higher than today.
20,000 years ago the sea level was 120 meters lower than today.
NATURE, 448 (2007) O. Norton, Is this what it takes to save the
world?
Geoengineering can be used to cool the Earth.
Introducing one or two million tons of sulphur into the
stratosphere every year as a way to keep the protective effects.
Large number of sliver-like fliers could be launched from Earth
and used to partially shield the Earth from Sun´s rays (to cut
down sunlight by about 2%).
NATURE, 448 (2007) M. Hopkin, Climate panel offers ground for
optimism
If CO2 emissions were given a cost of 50 USD per tonne, economic
forces could drive global emissions in 2030 20% to 50% lower than
they would otherwise have been.
Technologies and practices that can help mitigate climate change
(sector energy)
Currently available:
More efficient supply and distribution
Combined heat and power
Renewables
Nuclear
Early carbon capture and storage
Commercially available by 2030:
Carbon capture and storage
Advanced nuclear power
Advanced renewables
New solar concentrators and cells
GOALS:
People should be better educated and informed!
Scientific and technological development should
provide more energy efficient and environmentally
friendly devices!
Scientific and technological development should
provide abundant and ecologically cleaner energy
sources!
We should change our lifestyle to spend less energy!
Getting the people ready for action, rather than
passive or depressed!
Climatic Change in Croatia
5-year mean temperature in 1999.-2003. and 2004.-2008. in
Croatia.
Input mean annual temperature data are taken from
Meteorological and hydrological service of Republic of Croatia.
Fourteen climatological stations are chosen randomly from the
station network in Croatia, including coastal, continental and
mountain regions.
Climatological
Mean temperature (°C)
(°C)
station
1999.-2003.
2004.-2008.
Zagreb
13.02
12.68
Osijek
11.84
11.56
Pozega
11.82
11.36
Gospic
9.86
9.58
Crikvenica
15.58
15.15
Hvar
17.16
16.82
Split
16.96
16.66
Dubrovnik
17.22
16.84
Varazdin
11.40
11.04
Daruvar
11.48
11.06
Ogulin
11.22
10.76
Pazin
12.18
11.66
Zavizan (mountain top)
4.34
3.94
Knin
13.62
13.22
Mean temperature change: -0.38 °C.
Temperature change
-0.34
-0.28
-0.46
-0.28
-0.43
-0.34
-0.30
-0.38
-0.36
-0.42
-0.46
-0.52
-0.40
-0.40