Transcript ppt - Department of Statistics | Rajshahi University

Climate Change, Evidences and the
Science of Climate Change
M. Shamsul Alam, Ph.D.
Department of Geography &
Environmental Studies
University of Rajshahi,
Rajshahi 6205, Bangladesh.
Basic Terms
Weather: the current atmospheric conditions, including
temperature, rainfall, wind, and humidity at a given
place.
Climate: is the general weather conditions over a long
period of time., generally 30 or more years average of
weather.
Factors of Climate: Latitude, elevation, distance from
coast line/nearby water, surface type, vegetation, etc.
Elements of Weather and Climate: Temp, humidity ,
pressure, winds, cloud cover, precipitation, fog, visibility,
etc. (NOTE: Temperature and Precipitation are the two
most important elements)
Climate is defined as "average weather"
or the mean physical state of the
"climate system", the definition of which
has evolved in time (WMO, 1975). The
United Nation Framework convention on
Climate Change (UNFCC) comes up
with the definition in 1992 that the
climate system is a combination of the
atmosphere, Hydrosphere, Biosphere
and Geosphere along with interactions.
Climate Change has been defined by the
IPCC as “a change in the state of the climate
that can be identified (e.g., by using
statistical tests) by changes in the mean
and/or the variability of its properties and that
persists for an extended period, typically
decades or longer. Climate change may be
due to natural internal processes or external
forcing, or to persistent anthropogenic
changes in the composition of the
atmosphere or in land use” (IPCC, 2012).
This definition differs from that in the
UNFCCC’s earlier definition, where climate
change is defined as: “a change of climate
which is attributed directly or indirectly to
human activity that alters the composition of
the global atmosphere and which is in
addition to natural climate variability.
climate change attributable to human
activities altering the atmospheric
composition, and climate variability
attributable to natural causes.
History of climate change
1898: Swedish scientist Svante
Ahrrenius warns carbon dioxide
from coal and oil burning could
warm the planet
1988: NASA scientist James Hansen
tells U.S. Congress global warming
"is already happening now''
Exceptional drought hits the USA
Creation of the IPCC
1992: UNFCCC aims at stabilising
atmospheric concentrations of GHG
1997: UNFCCC parties approve Kyoto
Protocol mandating emission cuts by
industrial nations
1998/2005: Warmest year since recordkeeping began in mid-19th Century
Kyoto Protocol takes effect
The work of the IPCC is guided by the
mandate given to it by its parent
organisations: the World Meteorological
Organisation (WMO) and the United Nations
Environment Programme (UNEP)
Its role is to assess on a comprehensive,
objective and transparent basis the
scientific, technical and socio-economic
information relevant to understanding the
scientific basis of climate change, its potential
impacts and options for adaptation and
mitigation
The assessments carried out by the
IPCC have influenced global action
on an unprecedented scale
1. First Assessment Report (1990) had
a major impact in defining the content
of the UNFCCC
2. The Second Assessment Report
(1996) was largely influential in defining
the provisions of the Kyoto Protocol
3. The Third Assessment Report
(2001) focused attention on the
problems of the impacts of climate
change and the need for adaptation
4. The Fourth Assessment Report
(2007) is creating a strong basis for a
post Kyoto Protocol agreement
The IPCC`s Report of 2007 claimed that
(a) global average surface temperature has
increased 0.6°C  0.2°C since
the late
19th century, and it increased at a rate of
0.17°C per decade in the last 30 years.
(b) most of the warming observed over the last
50 years is attributable to
human activities,
in particular emissions of the greenhouse
gases, and
(c) if GHG emissions continue the warming will
also continue, with temperature increasing by
1.4°C-5.8°C by the year 2100.
The other effects of increased temperature, as
claimed by the IPCC report, are :
(a) sea level rise by 9-98 cms. due to
thermal expansion of oceans, and melting of
polar ice caps and glaciers,
(b) submergence of costal lowlands,
(c) increased frequency and intensity of
tropical cyclones and
(d) Increase in severe weather activity.
Last 1000 years temperature estimation by IPCC.
This graph is taken from the UNEP/GRID-Arendal site
The figure SPM-5 from the AR4shows temperature projections to 2100: “Solid lines
are multi-model global averages of surface warming for the scenarios A2, A1B and
B1, shown as continuations of the 20th century simulations. Shading denotes the
plus/minus one standard deviation range of individual model annual averages.
Surce: IPCC, 2007: Climate Change 2007: Synthesis Report
Now the questions are:
•Why the definition of climate change has
been changed?
•What caused climate change in the past?
Was the change in the historical past occurred
due anthropogenic activities even when there
was no people on our earth?
•Can anthropogenic activities change the
atmospheric composition which has a self
regulatory mechanism?
•How much CO2 is contributed by
anthropogenic activities?- evidence is only
0.28%. and there are many more other questions.
According to John R. Christi a fundamental
problem with the entire issue “is that
climate science is not a classic,
experimental science. As an emerging
science of a complex climate system, it is
pledged by uncertainty and ambiguity in
both observations and theory. Looking
classic, laboratory results, it easily become
hostage to opinion, groupthink, arguments
from authority, overstatement of
confidence ".
Distinguished Professor of Atmospheric Science and Director of Earth System Science Centre, University of
Alabama at Hantsville: Alabama State Climatologist: IPCC Lead Author: 2001 TAR ( Third Assessment Report) :
Contributor 1992 IPCC Supplement: Contributor 1994 Radiative Forcing of Climate Change: Key Contributor 1995
SAR ( IPCC Second Assessment Report; Contributing Author: IPCC 2007 Report (AR4)- Working Group I & II:
NASA Model for Experimental Scientific Achievement: Americal Meteorological Society Special Award for Satellite
Observations; Fellow, American Meteorological Society: testified to the US House and Senate Committees for lack
of evidence for catastrophic climate change caused by humans: one of the 3 members invited at the meeting on
Draft 5th Assessment Report of the IPCC
He further continues " the three fundamental
flaws in the current IPPC process are:
(1) the two-step political filter by which Lead
Authors are selected,
(2) the review activity granted the Lead
Authors who write the chapters and
synthesis reports,
(3) the very limited word count available for
each topic, which encourages short and
overconfident statements about questions
that in truth are plainly nasty to deal with"
(Christy, 2011: 16, 17).
Evidences
Theories about climate change and
consequent predictions about what will
happen to the Earth’s climate over coming
decades have become as much an issue of
politics and philosophy as they are an
issue of science. Despite assertions to the
contrary, there is no consensus among
scientists about the causes of climate
change. Scientists disagree over what
causes the Earth’s climate to change
because the mechanisms are unknown or
poorly understood, and d, and data are
sparse and unreliable.
In order to investigate the magnitudes, causes, and
effects of climate changes, longer series of global
average temperatures are necessary. The concept of
a global average temperature is simple, but in
practice it is not so easily estimated from nonsatellite data.
Inhomogeneities in climate records
Climate records (e.g. temperature and precipitation
measurements) are affected by changes in
measurement conditions, e.g., modernisation of the
instrumentation, location of the weather stations,
changes in observation rules, automation, etc. These
inhomogeneities are of the same order of magnitude
as anthropogenic climate
In 273 of the stations examined the
homogenization procedure increased positive
temperature trends, decreased negative
trends or changed negative trends to positive.
The expected proportion would be 50%.
Homogenization has amplified the estimation
of global temperature increase.
“homogenation practices used until today are
mainly statistical, not well justified by
experiments, and are rarely supported by
metadata. It can be argued that they often
lead to false results: natural features of
hydroclimatic times series are regarded as
errors and are adjusted.” ( Watts, A., 2012)
Explanation
•This graph (after Scotese and Bernier, 2001)
shows that over the past 600 my estimated
average earth temperature Have fluctuated
between 10º-12º C, with average earth’s
temperature being about 22º C, or 7º Cwarmer
than today.
•The graph also shows estimated average Co2
concentrations was significantly higher than
present values, 7000 ppm.
•Most evidence shows that temperature
changes cause changes in CO2 rather than
vice versa. On that, more later.
Source: Green K.C ,2008Global Climate changes:
Evidences of causes and effects..www.destone.co
nz
Images of Norther Hemisphere sea ice, purple
colour indicate concentration of ice. Source: Green
K.C. ,2008.www.destone.co.nz Global Climate
changes: Evidences of causes and effects,
Images of Norther Hemisphere sea ice, purple colour indicate
concentration of ice. Source: Green K.C. ,2008. Global
Climate changes: Evidences of causes and effects.
www.destone.co nz
Antarctic sea ice is increasing
despite warming. Source: Zang,
2007. J. of Climate, Vol. 20: 25152529.
How much evidence will it take to quiet the
claim that hurricanes are increasing in
frequency due to global warming?
Global Warming crusaders are particularly fond
of promoting the idea that we are having a
profound impact on hurricane activity—they
seem to never let an event go unclaimed.
At World Climate Report (WCR) have reviewed
dozens of papers from the leading scientific
journals presenting scant evidence to support a
strong link between global warming and
hurricane activity, and we hope you never get
bored with these essays.
Wang et al. begin their article “climate control of the
global tropical storm days (1965–2008”).Geophysical
Research Letters, 37, analyses the impact of the
rising sea surface temperature (SST) on tropical
cyclone (TC) activity is one of the great societal and
scientific concerns. With the observed warming of the
tropics of around 0.5°C over the past 4 to 5 decades,
detecting the observed change in the TC activity may
shed light on the impact of the global warming on TC
activity. Recent studies of the trends in the existing
records of hurricane intensity have resulted in a
vigorous debate in academic circlesThere no
increasing trends of hurricane/TC’s in any of the
world’s ocean basins.
Time series of the total annual number of tropical storm days during each TC year for
the global domain (GL), western North Pacific (WNP), North Atlantic (NAT), and SH
ocean (SHO), and Indo‐Pacific Warm Pool (IPWP, 17.5°S–10°N, 70°E –140°E). The
left‐hand side tick marks are for individual basins (region) and the right hand side are
for the global total. The mean numbers and standard deviations, maximum, and
minimum are shown in the legend (from Wang et al., 2010).
US All Category Landfalling Hurricanes (1850
– 2008) (Shows a decreasing trend). (Data
Source: NOAA)
Global Tropical Storm and Hurricane Frequency
(1979 – 2010) Blank solid line: Tropical storms,
Red dotted line: Hurricanes.
(Source: Dr. Ryan Moe, Center for Oceanic and
Atmospheric Studies, Florida State University)
It is difficult to project/predict sea level rise in
response to warming climates since factors
like
• thermal expansion,
• ocean oscillation,
• spatio–temporal fluctuations,
• melting of ice etc. are involved.
But the IPCC has argued that sea levels
could rise by an additional 1 meter by 2050
due to anthropogenic global warming.
Measurements from TOPEX and Jason series
of satellite radio altimeters have allowed
estimating global mean sea level. These
measurements calibrated against a network
of tide gauges and can now be used for
analysis.
Morner's new studies on Bangladesh (Morner
2010a, 2010b) and 2007a (updated 2010)
investigated the difference between the IPCC
models and the observational facts which is
presented in Figure 2.
The pink curve, “Models,” represents the IPCC’s combination of selected
tide-gauge records and corrected satellite altimetry data. The blue curve,
“Observations,” represents the observed estuatic sea level changes in the
field according to Mörner (1973) up to 1960 and thereafter. After 1965, the
two curves start to diverge, presenting two totally different views (separated
by the area with the question mark), where only one view can be tenable.
Sea level changes for the last 400 years as based on novel morphological and
stratigraphical evidence in the region of Kotka, Hiron Point and the Sibsa-Passur
river-system composed of the following facts: (1) a low sea level in the 18th
century recorded by the inter-clay unconformity and the findings of salt ovens,
(2) a major sea level rise giving rise to the delta surface and mangrove ecosystem,
(3) a sea level fall in the order of 10–20 cm as indicated by a lower present HTL,
and (4) a period of stability indicated by segments of dry land, habitation,
vegetation by species of low salt tolerance, progradation of coastal segments at
Hiron Point and Herbaria and the stratigraphy at Kotka. This curve exhibits many
similarities with the sea level curve of the Maldives (Mörner, N.-A., 2009, 2007b)
1. Some scientists believe that the above
predictions are too pessimistic, and too
unrealistic, because:
(a) The computer predictions are based
on present-day information.
(b) Present-day estimates of atmospheric
CO2 concentration are grossly
erroneous. Some scientists suggest that
such estimates may be 3-4 times higher
than reality
The Science of Climate Change
What Factors Determine Earth’s Climate?
•The climate system evolves in time under the
influence of its own internal dynamics and due
to changes in external factors that affect
climate (called ‘forcings’).
•External forcings include natural phenomena
such as variation in the rotational path of the
earth (110 K.Y., obliquity (44 k.y.), eccentricity
(19 & 23 k.y., sunspot cycles (11, 33, 88 years),
variation in the cosmic rays, volcanic
eruptions, solar variations and heat transfer in
the oceans (10 k.y), as well as human-induced
changes in atmospheric composition. Solar
radiation powers the climate system.
There are three fundamental ways to change
the radiation balance of the Earth:
1) by changing the incoming solar radiation
(e.g., by changes in Earth’s orbit or in the
Sun itself);
2) 2) by changing the fraction of solar
radiation that is reflected (called ‘albedo’;
e.g., by changes in cloud cover,
atmospheric particles or vegetation); and
3) 3) by altering the longwave radiation from
Earth back towards space (e.g., by
changing greenhouse gas concentrations).
Climate, in turn, responds directly to such
changes, as well as indirectly, through a
variety of feedback mechanisms.
Climate Feedback Mechanisms
Positive and Negative Feedbacks
Positive Feedback Mechanism
Assume that the Earth is warming.
- Warming leads to more evaporation from
oceans, which increases water vapor in
atmosphere.
-More water vapor increases absorption of
IR, which strengthens the greenhouse
effect.
-This raises temperatures further, which
leads to more evaporation, more water
vapor, warming…
“Runaway Greenhouse Effect”
Negative Feedback Mechanism
Again assume that the Earth is warming.
- Suppose as the atmosphere warms and
moistens, more low clouds form.
- More low clouds reflect more solar
radiation, which decreases solar heating
at the surface.
- This slows the warming, which would
counteract a runaway greenhouse effect
on Earth.
Balance of Positive and Negative
Feedbacks
•Atmosphere has a numerous checks
and balances that counteract climate
changes.
•All feedback mechanisms operate
simultaneously.
•All feedback mechanisms work in both
directions.
•The dominant effect is difficult to
predict.
The climate system is very complex.
Contains hundreds of feedback
mechanisms
All feedbacks are not totally
understood.
Three general climate change
mechanisms:
Astronomical
Atmospheric composition
Earth’s surface
ORBIT AN ELLIPSE (J. Kepler, 0.0167)
eccentricity varies ± 98,000 yr period (0.0005 0.0607)radius = 155 x 106 km, so varies 9.3 x
106 km Superscript
TILT OF AXIS OF ROTATION 23.5o
tilt (obliquity) varies ± 41,000 yr period (20o - 25o)
Seasons in N - S Hemispheres Opposite
Diagram of the precision of the equinoxes
Precession Cycle ~ 20k, North-South
SUNSPOTS
Cosmoclimatology: A New Theory of Climate
Change
Henrik Svensmark in 1995 draws attention to an
overlooked mechanism of climate change: clouds
seeded by cosmic rays.
Changes in the intensity of galactic cosmic rays alter
the Earth’s cloudiness. A recent experiment has
shown how electrons liberated by cosmic rays assist
in making aerosols, the building blocks of cloud
condensation nuclei, while anomalous climatic trends
in Antarctica confirm the role of clouds in helping to
drive climate change. Variations in the cosmic-ray
influx due to solar magnetic activity account well for
climatic fluctuations on decadal, centennial and
millennial timescales.
Data on cloud cover from satellites, compared
with counts of galactic cosmic rays from a ground
station, suggested that an increase in cosmic rays
makes the world cloudier. This empirical finding
introduced a novel connection between
astronomical and terrestrial events, making
weather on Earth subject to the cosmic-ray
accelerators of supernova remnants in the Milky
Way. The result was announced in 1996 at the
COSPAR space science meeting in Birmingham
and published as “Variation of cosmic-ray flux and
global cloud coverage – a missing link in solarclimate relationships” (Svensmark and FriisChristensen 1997).
At different levels in the atmosphere
(high >6.5 km, middle 6.5–3.2 km and
low <3.2 km) the blue line shows
variations in global cloud cover
collated by the International Satellite
Cloud Climatology Project. The red
line is the record of monthly
variations in cosmic-ray counts at the
Huancayo station. While there is no
match at the higher altitudes, a close
correspondence between cosmic rays
and clouds low in the atmosphere is
plain to see. (Marsh and Svensmark,
200
Contribution of GHG’s & their Sources
Gas
%
Nature
Human
Water Vapour
Carbon dioxide
Methane
Nitrus Oxide
Ozone & others
.
Total
95
3.618
0.360
0.950
0.072
94.999
3.502
0.2294
0.903
0.025
0.001
0.117
0.066
0.047
0.047
100.0
99.72
0.28
• Trick to hide the decline
At 1.31pm on Tuesday, November 16, 1999 Jones
wrote an email to three scientists stating:
"I've just completed Mike's Nature trick of adding in
the real temps to each series for the last 20 years (ie
from 1981 onwards) and from 1961 for Keith's to hide
the
• "Climategate" is the term used in the media and by
climate sceptics to refer to the theft and
publication of a selection of emails sent over a 13year period by Professor Phil Jones and his
colleagues at the Climatic Research Unit (CRU) at
the University of East Anglia (UEA). The security
breach and the content of the emails have been
the subject of five official inquiries, three of them
in the UK, as well as an ongoing police
investigation."
In response to some sustained criticisms and a
heightened level of public scrutiny of the Fourth
Assessment Report, the United Nations and IPCC
asked the Inter Academy Council (IAC) to
assemble a committee to review the processes and
procedures of the IPCC and make
recommendations for change that would enhance
the authoritative nature of its reports. The IAC’s
main recommendations relate to IPCC’s
governance and management, its review process,
characterizing and communicating uncertainty,
communications, and transparency in the
assessment process ( for details see chapter 5 of
the IAC Report, 2010).
Theories about climate change and
consequent predictions about what will
happen to the Earth’s climate over coming
decades have become as much an issue of
politics and philosophy as they are an issue
of science. Despite assertions to the
contrary, there is no consensus among
scientists about the causes of climate
change. Scientists disagree over what
causes the Earth’s climate to change
because the mechanisms are unknown or
poorly understood, and data are sparse and
unreliable.