Transcript Climate change

Current State of Scientific
Understanding
of Climate Change
Bob Watson
Part I
Climate Change and Projected
Impacts
Most (greater than 50%) of the Observed Warming of the
Last 50 Years is Attributable to Human Activities
(a) Observed and
modeled changes
disagree between
1950 and 2000 with
natural forcing alone
(c)
(b) observed and
modeled changes
disagree between
1920 and 1970
with anthropogenic
forcing alone
Observed and modeled changes in are in good agreement with
natural and anthropogenic forcing
Climate Change
• Climate change is both a development and global
environmental issue, which undermines:
• environmental sustainability
• poverty alleviation and the livelihoods of the poor
• human health
• national and regional security
• Climate change is an inter- and intra-generational
equity issue:
• developing countries and poor people in developing
countries are the most vulnerable
• the actions of today will affect future generations
because of the long life-times of the greenhouse
gases and the inertia within the climate system
Atmospheric composition
Since the industrial
era began,
human activities
have increased
the atmospheric
concentrations
of greenhouse
gases, which
tend to warm the
Earth, and sulfate
aerosols, which
tend to cool
the Earth, primarily
due to energy and
land management
practices
Climate Change
• The Earths climate has changed, in part due to
human activities, and is projected to continue
to change, globally and regionally:
• Warmer temperatures
• Changing precipitation
• Higher sea levels
• Retreating glaciers
• Reduced arctic sea ice
• More frequent extreme
weather events
•
heat waves, floods and droughts
Surface Temperature
A mid-range
projection of
change from 1990
to 2100 – a global
average of 3.1oC
The full projected
range for changes
in global average
temperature is
1.4oC to 5.8oC
Observed
changes from
1976 to 1999
Projected changes from 1990 to 2100
Precipitation
Projected changes
in precipitation
from 1990 to 2100
Observed changes
in precipitation
from 1900 to 2000
Extreme Weather Events
Model Prediction
Confidence in
Observed Change
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Higher maximum temperatures and more hot days
66-90%
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Higher minimum temperatures, fewer cold days
and frost days over nearly all land areas
90-99%
Reduced diurnal temperature range over most
land areas
90-99%
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Increased heat index over most land areas
90-99%
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More intense precipitation events over many areas
90-99%
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Increased summer continental drying and associated risk
of drought – mid-latitude continental interiors
66-90%
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Recent Findings
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Compared to the IPCC TAR, there is greater clarity and reduced
uncertainty about the impacts of climate change
A number of increased concerns have arisen:
• Increased oceanic acidity likely to reduce the oceans capacity to
absorb carbon dioxide and effect the entire marine food chain
• A regional increase of 2.7oC above present (associated with a
temperature rise of about 1.5oC above today or 2oC above preindustrial level) could trigger a melting of the Greenland ice-cap
• An increase in ocean surface temperature of 1oC is likely to lead to
extensive coral bleaching
• Reversal of the land carbon sink – possible by the end of the Century
• Possible destabilization of the Antarctic ice sheets becomes more likely
above 3oC – the Larson B ice shelve is showing signs of instability
• The North Atlantic Thermohaline Circulation may slow down or even
shut down
Climate change is already affecting
natural and social systems
The poor will face the greatest
challenges from climate change.
100%
The rate has double in this decade
80%
Percentage affected
2 Billion people in developing
countries were affected by a climate
related disaster in the 1990s.
LDC
60%
Dev'ing
CIT
40%
Dev'ed
20%
4,000
Number affected (Millions)
0%
1970s
1980s
1990s
2000s
3,000
Dev'ed
CIT
2,000
Dev'ing
LDC
1,000
-
1970s
1980s
1990s
2000s
40 to 80% of the population in
developing countries versus a few %
in more developed countries
Ethiopia
A water rich
developing
country, but
with GDP still
tied to yearly
rainfall
variations
Climate variability is already a
major impediment to
development.
25
20
15
10
5
0
%
0
2000
1999
1998
1997
1996
1995
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1991
1990
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1983
-20
1982
-5
-10
-15
-40
rainfall variability
-60
-20
GDP growth
-25
Ag GDP growth
-80
-30
year
Preliminary results from : A Country Water Resources Assistance Strategy for Ethiopia
From Claudia Sadoff
WHO
estimates
that
>150,000
people
are dying
each year
due to
climate
change
Wheat
now being
grown in
areas 2 C
cooler and
4.5 C
warmer
than in the
1920s.
Shows
rapid
adaptation
in wheat
Pew
Climate change is a development
issue – right now and will
become even more so in the
future
Climate Change
Human-induced climate change is projected
to:
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Decrease water availability and water quality in many aridand semi-arid regions – increased risk of floods and droughts
in many regions
Decrease the reliability of hydropower and biomass
production in some regions
Increase the incidence of vector- (e.g., malaria and dengue)
and water-borne (e.g., cholera) diseases, as well as heat
stress mortality, threats nutrition in developing countries,
increase in extreme weather event deaths
Decrease agricultural productivity for almost any warming in
the tropics and sub-tropics and adverse impacts on fisheries
Adversely effect ecological systems, especially coral reefs,
and exacerbate the loss of biodiversity
% change in runoff by 2050
Many of the major “food-bowls” of the world are projected to
become significantly drier
Crop yields are projected to decrease in the tropics
and sub-tropics, but increase at high latitudes
Percentage
change in average
crop yields for a
mid-range climate
change scenario
Even as soon as
2020 crop yields
in SSA and parts
of Asia are
projected to
decrease by up to
20%
Estimated 10-15% of the world’s
species will be committed to
extinction over next 30 years
independent of climate change
Biodiversity underlies
all ecological goods and
services – provisioning,
regulating, supporting
and cultural
Climate change will
exacerbate the loss of
biodiversity
Climate Change and Conflict
• Tens of millions of people displaced
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Low lying deltaic areas
Small Island States
• Food shortages where there is hunger and famine
today
• Water shortages in areas already with water shortages
• Natural resources depleted (e.g., coral reefs, forests),
loss of ecological goods and services
• Increased incidence of disease
• Increased incidence of severe weather events
Climate Change, coupled with other local
and global environmental issues can lead to
local and regional conflict
Part II
Political Situation
and
Adaptation and Mitigation
The Kyoto Protocol
• All industrialized governments, except the US and Australia
have ratified the Kyoto Protocol, which contains:
•
A commitment to reduce GHG emissions, on average, by
about 5% between 2008-2012 relative to 1990
•
The flexibility mechanisms – carbon trading
•
Land-use, land-use change and forestry activities
•
Funding mechanisms to assist developing countries
• The US stated that the Kyoto Protocol was flawed policy because
it was neither fair nor effective and not in the best interests of the
US
• scientific uncertainties – Article 3 (precautionary principle)
• high compliance costs – inconsistent with IPCC
• ineffective without the participation of the large developing
countries
Beyond Kyoto
•
Without the US taking real action to limit their GHG emissions it is
doubtful that there will be a second commitment period – some
OECD countries will withdraw and large developing countries, i.e.,
China and India will not be willing consider any commitments
•
Without a commitment of governments to limit GHG emissions
beyond 2012 (the end of the first commitment period) the carbon
market will remain soft and the private sector is unlikely to enter
in a meaningful manner
•
The real question for governments is whether to:
• set an emissions target for a second commitment period
(2013-2017) or whether to set a long-term stabilization
target for climate change (e.g., 2oC above the pre-industrial
level) or some other long-term framework
• this would require a global emissions target – the challenge
would be to agree on intermediate emissions targets and an
equitable allocation of emissions rights
Warming resulting from different stabilized
concentrations of greenhouse gases
pre-industrialized level - 280 ppm, current level - 370 ppm
Even if the atmospheric concentration of
carbon dioxide was stabilized at today’s
level, the Earth’s temperature would still
increase by over 0.5oC
10
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The atmospheric concentration of carbon
dioxide equivalent (i.e., taking into
account other GHGs) is close to 450ppm.
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6
Temperature change
relative to 1990 (C )
Temperature
change at
equilibrium
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The figure demonstrates that even if the
atmospheric concentration of carbon
dioxide was stabilized at 450-550 ppm, a
significant increase in temperature is
projected, thus adaptation is an
important part of a climate strategy
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3
2
1
0
450 550 650 750 850 950 1000
Eventual CO2 stabilisation
level (ppm)
Conclusions from Exeter Meeting
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Probability analysis suggests that to limit warming to 2oC above
pre-industrial levels with a relatively high certainty requires the
equivalent concentration of carbon dioxide to stay below 400ppm
Stabilization of the equivalent concentration of carbon dioxide at
450ppm would imply a medium likelihood of staying below 2oC
above pre-industrial levels
If the equivalent concentration of carbon dioxide were to rise to
550ppm it is unlikely that warming would stay below 2oC above
pre-industrial levels
The World Energy Outlook (2004) predicts that carbon dioxide
emissions will increase by 63% over 2002 levels by 2030. This
means that in the absence and urgent and strenuous actions to
reduce GHG emissions in the next 20 years, the world will almost
certainly be committed to a warming of between 0.5oC and 2oC
relative to today by 2050, i.e., about 1.1oC and 2.6oC above preindustrial
A climate risk approach
Climate risk management means that we
should assess and act upon, the threats
and opportunities that result from
both existing and future climate variability,
including those deriving from climate change.
What can be done?
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Change farming systems
Strengthen infrastructure
Conserve natural buffers
(eg forests including
mangroves)
Store more water
Improve disaster
preparedness
Provide insurance?
Migrate
But all have downsides
How are we going?
A few developed countries are
considering comprehensive
adaptation plans
Several studies suggest that about
40% of ODA projects &
development loans are subject to
some climate risk.
But few (2%) consider climate risk
in their design
But everyone now wants to
“mainstream” adaptation
Pitfalls to mainstreaming adaptation
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Not appreciating the immediacy
“Projectisation” of adaptation
• Sees adaptation as a series of projects but
separates adaptation form core development
planning
• Often embroils adaptation in institutional
rivalries
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“Poker chip” in the climate negotiations
Seeking the ideal at the expense
of the pragmatic
• E.g. Seeking only adaptation – mitigation
synergies
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Endless loop of “better
information”
• Downscaling & impact modelling
An adapted world
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A warmer world
More climate extremes and
disasters
Greater preparedness to
deal with them
More climate & water
awareness (& more dams)
Changed agricultural zones
Greater threats to and
management of natural
habitats
Physical or natural barriers?
Forced migration
Potential Actions to Mitigate GHG Emissions
Energy Efficiency and Conservation: Efficient vehicles, Reduced
use of vehicles, Efficient buildings, and Efficient coal plant
Fuel shift: Gas power for coal power
CO2 Capture and Storage: Capture CO2 at power plant; Capture CO2
at H2 plant; Capture CO2 at coal-to- synfuels plant; --- geological storage
Nuclear fission: Nuclear power for coal power
Renewable Electricity and Fuels: Wind power for coal power; PV
power for coal power; Wind H2 in fuel-cell car for gasoline in hybrid car;
Biomass fuel for fossil fuel
Forests and Agricultural Soils: Reduced deforestation, plus
reforestation, afforestation and new plantations; and Conservation tillage
Policy Instruments
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Policies, which may need regional or international
agreement, include:
• Energy pricing strategies and taxes
• Removing subsidies that increase GHG emissions
• Internalizing the social costs of environmental
degradation
• Tradable emissions permits--domestic and global
• Voluntary programs
• Regulatory programs including energy-efficiency
standards
• Incentives for use of new technologies during market
build-up
• Education and training such as product advisories and
labels
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Accelerated development of technologies requires intensified
R&D by governments and the private sector
Clean Energy and Development:
Towards an Investment Framework
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Covers three interlocking and complementary issues:
the need for, and investment requirements of,
meeting modern energy needs for developing
countries over the long term in a manner that
provides attention to efficiency and local
environmental considerations;
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the additional steps needed in the energy,
transport and industrial sectors to address
climate change mitigation through the reduction
of greenhouse gases; and
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the impact of climate change and the need for
developing countries to adequately adapt to
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Conclusions
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Increased access to energy is critical for poverty alleviation and
economic growth
Climate change undermines development and environmental
sustainability
Access to affordable energy while also addressing climate change
will require a collaborative effort involving governments, private
sector, financial institutions, NGOs, and the research community
• Increased public and private sector funding for energy S&T
• Innovative public-private partnerships and technology transfer are
needed
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The Bank can play a critical role in assisting client countries
reduce GHG emissions and adapt to climate variability and change
Developing a robust carbon market can reduce emission reduction
costs in OECD and improve access to new technologies in
developing countries - carbon financing is a source of new
financing (non-ODA)
There are cost-effective and equitable solutions, but political will
and moral leadership is needed