climate change 101 - introduction to climate change science (undp presentation)
DESCRIPTION
UNDP presentation by Matt SpannagleTRANSCRIPT
2
Introduction
Climate change Science
•Climate change policies (UNFCCC, KP etc)
• Climate change mitigation & adaptation response
• Climate finance & carbon finance (Green Fund, CDM, EUETS, etc)
• Climate change & UNDP
3
Agenda
Science of Climate Change• Greenhouse Effect• Greenhouse Gases and their energy absorption• Global Warming Potentials• Greenhouse Gas Concentrations in the Atmosphere• Modeling and predicting future effects• Climate Change Impacts
4
The Greenhouse Effect
Natural process
Well-understood principle that greenhouse gases trap heat in the atmosphere (Arhenius,1896)
Average temperature would be 33°C cooler without greenhouse effect
Greenhouse gases allow short wavelength ultraviolet (UV) and visible light from the sun to pass through the atmosphere, but absorb some of the heat re-emitted from the earth as longer wave length infrared radiation (IR)
5
6
Global Energy Budget
Kiehl and Trenberth, 1997: Earth’s Annual Global Mean Energy Budget, Bull. Am. Met. Soc. 78, 197-208
7
Albedo
0 = perfect absorption 1 = perfect reflection
Material Albedo
Sand 0.18 – 0.28
Grassland 0.16 - 0.20
Green Crops 0.15 - 0.25
Forests 0.14 – 0.20
Dense Forests 0.05 – 0.10
Fresh Snow 0.75 – 0.95
Old Snow 0.40 – 0.60
Cities 0.14 – 0.18
Oceans with sea ice Up to 0.60
Equatorial oceans at noon 0.05
8
Greenhouse GasesCarbon Dioxide
CO2
Methane CH4
Nitrous Oxide N2OSynthetic Gases•Hydrofluorocarbons (HFCs) HnFmCo
•Perfluorocarbons (PFCs) CnFm
•Sulphur Hexafluoride SF6
•Ethers & Halogenated Ethers (NMVOCs) HnCmOCoHp
Water Vapour H2O** Note that water vapour is largest contributor to greenhouse gases (~ 95%) but the majority of the sources are not anthropogenic in nature
9
Effect of GHGs on radiationatmosphere is fairly transparent to incoming solar radiation
Different gases absorb at different wavelengths
Natural mix of gases in the atmosphere absorbs some of the long-wave radiation emitted by the earth
All gases have peaks of absorption at certain wavelengths, dependant on molecular properties. Some absorb almost 100% of the energy radiated from the earth at a particular wavelength
Some earth radiation escapes the atmosphere because it is at a wavelength where the atmospheric concentration of gases is not sufficient to absorb outgoing radiation
Gases that absorb at these wavelengths are effective at increasing the temperature of the earth
10
The Sun’s and Earth’s Radiation
11
Absorption Spectrum
12
Solar Radiation (incoming)
H2O CO2 CH4 N2O
Solar irradiation curves, showing location of atmospheric absorption bands
13
Absorptivity of Earth’s Radiation Curves (outgoing)
14
Global Warming Potentials
Gas Chemical Formula
Lifetime (years) Global Warming Potentials 1996
20 yrs 100 yrs 500 yrs
Carbon Dioxide CO2 50-200 1 1 1
Methane CH4 12.0±3 56 21 6.5
Nitrous Oxide N2O 120 280 310 170
Trifluoromethane (HFC-23)
CHF3 264 9,100 11,700 9,800
Carbon Tetrafluoride
CF4 50,000 4,400 6,500 10,000
Sulphur Hexafluoride
SF6 3,200 16,300 23,900 34,900
15
Background InformationCarbon Cycle
Atmosphere
HydrosphereLithosphere
CO2
Biosphere
Producers
Consumers
DecomposersCarbonatesin Solution Carbonate Rocks
Fossil Fuels
Photosynthesis
Combustion and/or
Respiration
16
Background Information - Carbon CycleAtmospheric Carbon Dioxide (640)
Limestone, dolomite(18,000,000)
Coal, oil, natural gas(25,000,000)
Dissolved total CO2(30,000)
Algae (5)
Animals
Bacteria, organic(1500)
OCEANS
Respiration (50)
Assimilation(50)
LAND
Animals
Bacteria,fungi
Dead Organic Matter (700)
Plants (450)
Exchange (84)Volcanoes (2) Assimilation (35) Respiration (35)
Sedimentation (<1)
Co
mb
ust
ion
(1
)
De
po
sitio
n/D
isso
lutio
n (
<1
)
(25)
Ricklefs, Robert E., The Economy of Nature, 3rd Ed.. 1993, W.H. Freeman and Co., New YorkPools (billion metric tons) Fluxes (billion metric tons/year)
17
Links with other atmospheric pollutant issues
Clean air / Acid rain• Most processes that produce GHGs also produce other air pollutants
• Reductions in related processes typically lead to the reduction in both but some reductions of one actually increase the other
Stratospheric ozone depletion• Ozone depleting substances (ODS) are generally powerful GHGs• Replacement of phased out ODSs with larger quantities of GHGs
cancels beneficial effect of initial reduction on climate change (e.g. growth in HFCs due to phase out of CFCs)
• Montreal Protocol – 1987, landmark international agreement to protect the ozone layer
18
Combined Annual Land-Surface Air and Sea Surface Temperature Anomalies (1861 to 2000, cf 1961 -1990).
Two standard error bars shown on the annual number.
Intergovernmental Panel on Climate Change. IPCC Third Assessment Report - Climate Change 2001: The Scientific Basis – Technical Summary. Geneva, 2001.
19
Northern Hemisphere Temperature Reconstruction (1000 to 2000)
Intergovernmental Panel on Climate Change. IPCC Third Assessment Report - Climate Change 2001: The Scientific Basis – Technical Summary. Geneva, 2001.
20
Greenhouse Gas Concentrations in the Atmosphere
IPCC Third Assessment Report - Climate Change 2001: The Scientific Basis – Technical Summary. Geneva, 2001.
21
Variations of temperature, CH4 & atmospheric CO2
Intergovernmental Panel on Climate Change. IPCC Third Assessment Report - Climate Change 2001: The Scientific Basis – Technical Summary. Geneva, 2001.
CO2 (2001)
CH4 (2001) (> 2X scale)
Data derived from air trapped within ice cores from Antarctica
22
More recent - CO2 & Temperature
Two standard error bars shown on the annual number.
Intergovernmental Panel on Climate Change. IPCC Fourth Assessment Report - Climate Change 2007
2009: 387ppm
23
Current evidence
24
Current evidence - Extensive thinning on the margins of Greenland and Antarctica
25
The future?
Up to this point - facts that are well understood, and not in dispute.
What does it mean for the future?
26
• 1000 to 1861, N. Hemisphere, proxy data • 1861 to 2000, Global, instrumental• 2000 to 2100, SRES projections
Modeled Variations of mean Earth’s Surface Temperature - 1000 to 2100
IPCC, TAR - Climate Change 2001: The Scientific Basis – Technical Summary. Geneva, 2001.
27
Global variability in Projected Changes in Annual Temperatures for the 2050s
28
…but reality is not average…
mean<5% > 5%
22oC12oC 32oC15oC 25oC 35oC
11oC 25oC 39oC
Historic
Average +
variability
‘average’ increase
May 1st
Historic ‘average’ increase of 3oC Average (3) + variability of 4oC
29
NASA data for Jan-Apr 2010, 0.75oC above 1951-80 base period
What we’re seeing…..
30
Moscow, August 2010. Hottest summer for at least 130 years, probably for last 1000 years, sparking forest fires and underground peat fires
What we’re seeing…..
31
Global variability in Projected Precipitation
32
Pakistan, August 2010
What we’re seeing…..
33
Flooding in Ostritz near Czech-Polish border, 2010
What we’re seeing…..
34
Rapid loss of Arctic sea ice
Intergovernmental Panel on Climate Change. IPCC Fourth Assessment Report - 2007
35
Context
The merchant vessel Fraternity passed Nowaja Zemlya, regarded by Russia as the official exit point of the Northern Sea Route, in September 2009.
What we’re seeing…..
36
…but
Models are not reality The earth’s climate is extraordinarily complex
Some things that may have a large impact on the modeled projections are not well understood
* not all changes will be negative
37
Climate Change Amplifying Effects (Positive Feedback)
Warming will reduce snow cover or melt part of the Arctic ice sheet. This reduces albedo increasing the temperature further.
Methane locked in earth's permafrost will be released when heated.
Higher temperature increases the amount of water vapour in the air.
Increased heat encourages the rate of respiration in plants and animals releasing CO2.
Heat increases the volume of water in the oceans and seas (thermal expansion) consequently increasing the magnitude of sea level rise.
Heat accelerates decomposition of organic matter in soils & peat, which releases additional CO2 into the atmosphere.
38
Climate Change Decreasing Effects (Negative Feedback)
More evaporation results in more cloud cover, increasing earth’s albedo and thereby reducing the temperature
More evaporation increases polar precipitation of snow, which increases earth's albedo
Increased concentrations of CO2 in the atmosphere promotes photosynthesis globally (‘fertilisation effect’), which sequesters more carbon into the biosphere
39
Some Potential Climate Change Impacts
Typically media focus on catastrophic and dramatic events (eg: sea level rise, tropical cyclones etc)
Greater impact from loss of predictability of climate in a location or region:
•Will frost trigger the flowering of fruit-crops? •Will the winter be cold enough to kill off insect pests?•Will activities attracting tourists be possible (e.g. skiing)•Will the maximum daily temperature exceed a survival threshold for the local specialty crop?
•Which crop should be planted, given the amount of rainfall may be much less than previous years?
