Climate Change What we know And What we need to know
John Tyndall of Carlow "The waves of heat speed from our earth through our atmosphere towards space. These waves dash in their passage against the atoms of oxygen and nitrogen, and against molecules of aqueous vapour. Thinly scattered as these latter are, we might naturally think of them meanly as barriers to the waves of heat."
Climate Change The Science
The Greenhouse Effect (Arrhenius,1896)..most escapes to outer space and cools the earth... SUN Sunlight passes through the atmosphere.. but some IR is trapped by some gases in the air, thus reducing the cooling...and warms the earth. Infra-red radiation is given off by the earth...
Carbon the mobile element
Carbon dioxide in the atmosphere
Projected concentrations of CO 2 during the 21 st century are two to four times the pre-industrial level
Projected levels of CO 2 Concentration in Ice Core Samples and Projections for Next 100 Years Projected (2100) Projected (2100) 700 650 atmospheric CO 2 Vostok Record during IPCC the IS92a Scenario next 100 Law Dome Record years Mauna would Loa Record be higher than at anytime in the last 440,000 yrs Current (2001) Current (2001) 600 550 500 450 400 350 300 CO2 Concentration (ppmv) 250 200 400,000 300,000 200,000 100,000 0 150 Years Before Present (BP 1950)
Projected Temperatures During the 21 st Century Are Significantly Higher Than at Any Time During the Last 1000 Years
N HEMISPHERE TEMPERATURE 1000-2100 Temperature rise (degrees C) Met Office / Hadley Centre Proxy-observations Weather stations Predictions (high emissions) Predictions (low emissions)
GLOBAL TEMPERATURES 1861-2003
Temperature trend 1976-2000 Trend in ºC per century
Sea Levels have risen
Climate Change Natural Disasters
Mother Earth -- Our Home It is has water, oxygen and a hospitable climate
World Population 6,056,528,577 The Challenge: Sustainable Management of an Ever-Changing Planet
The Challenge: Sustainable Energy
The Challenge: Food Security
Food production needs to double to meet the needs of an additional 3 billion people in the next 30 years Climate change is projected to decrease agricultural productivity in the tropics and sub-tropics for almost any amount of warming
The Challenge: Water Security
Water Services Climate change is projected to decrease water availability in many arid- and semi-arid regions One third of the world s population is now subject to water scarcity Population facing water scarcity will more than double over the next 30 years
Estimated 10-15% of the world s species could become extinct over the next 30 years Biodiversity underlies all ecological goods and services Climate change will exacerbate the loss of biodiversity
Natural Disaster trends Billions of USD per decade Geological 495 500 450 Hydrometeorological 400 345 350 300 250 200 160 150 100 50 4 11 14 24 47 88 103 0 Source: EM-DAT: The OFDA/CRED International Disaster Database - www.emdat.net - Université Catholique de Louvain - Brussels - Belgium 56-65 66-75 76-85 86-95 96-05 decade
Natural Disaster trends 3 2.5 Millions of casualties per decade 2.66 Geological Hydrometeorological 2 1.73 1.5 1 0.65 0.67 0.5 0.05 0.17 0.39 0.22 0.25 0.22 0 56-65 66-75 76-85 86-95 96-05 decade Source: EM-DAT: The OFDA/CRED International Disaster Database - www.emdat.net - Université Catholique de Louvain - Brussels - Belgium
Number of Disasters (1980-2005) Drought 4% Extreme Temperature 11% Flood 35% Epidemic, famine, insects 5% Volcano 0.5% Earthquake 11% Slides 4% Windstorm 22% Wild Fires 8% Nearly 90% of disasters are related to hydro-meteorological factors. Source: EM- DAT: The OFDA/CRED International Disaster Database - www.em-dat.net - Université Catholique de Louvain - Brussels - Belgiumc
Economic Losses (1980-2005) Wild Fires 2.45% Slides 0.4% Windstorm 38% Flood 28% Extreme Temperature 1.8% Drought 5% Earthquake 24% Tsunami 1% Nearly 75% of economic losses are related to hydro-meteorological factors Source: EM-DAT: The OFDA/CRED International Disaster Database - www.emdat.net - Université Catholique de Louvain - Brussels - Belgium
Loss of Human Life (1980-2005) Drought 28% Flood 9% Extreme Temperature 3.4% Slides 0.9% Windstorm 13% Wild Fires 0.06% Epidemic, famine, insects 19% Earthquake 14% Tsunami 11% Volcano 2.5% Nearly 70% of loss of life are related to hydro-meteorological factors Source: EM-DAT: The OFDA/CRED International Disaster Database - www.emdat.net - Université Catholique de Louvain - Brussels - Belgium
Climate Change Modelling Climate Change
GJJ1999 PREDICTING CLIMATE CHANGE EMISSIONS CONCENTRATIONS CO 2, methane, etc. HEATING EFFECT Climate Forcing. CLIMATE CHANGE Temp, rain, sea-level, etc. IMPACTS Flooding, food supply, etc. feedbacks Scenarios from population, energy, economics models Carbon cycle and chemistry models Gas properties Coupled climate models Impacts models Met Office/Hadley Centre
Met Office Hadley Centre Development of climate models 2003 ATMOSPHERE LAND OCEAN ICE SULPHUR CARBON CHEMISTRY 1999 ATMOSPHERE LAND OCEAN ICE SULPHUR CARBON 1997 ATMOSPHERE LAND OCEAN ICE SULPHUR 1992 ATMOSPHERE LAND OCEAN ICE Component models ATMOSPHERE LAND OCEAN are constructed off-line and coupled in to the 1985 ATMOSPHERE LAND climate model when sufficiently developed 1960s ATMOSPHERE
19 levels in atmosphere 2.5 lat 3.75 long 30km THE HADLEY CENTRE THIRD COUPLED MODEL - 20 levels in ocean 1.25 1.25 HadCM3-5km
GLOBAL TEMPERATURE RISE Global temperature rise, degrees C High Emissions Medium-High Medium-Low Low Start to diverge from mid-century
GLOBAL TEMPERATURE RISE following stabilisation of greenhouse gas concentrations at current levels Jason Lowe, Hadley Centre
GJJ1999 CHANGES IN SOLAR ENERGY Lean, Beer & Bradley
Temperature change ºC 1.0 0.5 0.0 OBSERVED AND SIMULATED CHANGE natural factors only observed model simulation + -0.5 1850 1900 1950 2000
Temperature change ºC OBSERVED AND SIMULATED CHANGE natural & man-made factors 1.0 0.5 0.0 observed model simulation + + -0.5 1850 1900 1950 2000
Brigitte Koffi, University of Fribourg Changes in summer Tmax (june-july-august) (Differences between 2071-2100 and 1961-1990) (HIRHAM RCM) Mean temperature 90% quantile +2 +4 +6 +8 +10 +12 C
August 2003 temperature anomaly relative to late 19 th century. Current European summer warming well reproduced by models; we ascribe a large fraction of the increased likelihood of hot summers to human factors. Hadley Centre
CHANGE IN ARCTIC SEA ICE EXTENT September, due to IPCC High emissions Met Office / Hadley Centre 0.15 0.3 0.45 0.6 0.75 0.9 Fraction of ocean covered by sea ice
Climate Change Regional Modelling
Regional Climate Modelling
Regional Climate Modelling
Temperature Difference February over 60 years
Temperature Difference August over 60 years
Rainfall January 2021-2060
Rainfall Difference January over 60 years
Rainfall June 2021-2060
Rainfall Difference June over 60 years
CHANGE IN STORM SURGE HEIGHT 50yr return period; 2080s high emissions
What would I be forecasting in Winter: More Atlantic storms 2050? More rain will bring more flooding to eg the Shannon, towns such as Clonmel etc Very little frost Southeast Storms: Coastal flooding of parts of Dublin, Arklow, Wexford, Waterford, Cork..
What would I be forecasting in Summer: Warm and dry 2050? Drought in the east and southeast Water shortages around the main urban centres Beach weather will be good but.. How will we get to them??
The Farming Forecast Greater competition for water Sharpens urban rural conflict Fields wet from October to April?? Cannot get livestock, machinery onto the land Potato Problems! Not enough summer rain to allow proper crop maturity. Harvesting problematic in the wetter winters. Grazing will retreat westwards
A broader view of risk factors, a wider time frame How to provide early warning and foresight of Declining environmental state? Risk-raising development projects? Social communications and capacity weaknesses? Trends in markets, prices, migration, conflict, health vulnerability? Element Day-Week-Month- Year-Decade Weather, tides, floods, soils XXXX XXX Reservoirs, snow pack XXXXXXXX People exposed, conflict, migration XXXXXX Crop production, food prices XXXXXX Food reserves, food aid XXXXXX Environmental management XXXXXXXX Industry, urban, infrastructure design
SUMMARY Global warming of about 0.7 C in last century Global (and continental-scale) temperature rise over last 50 years very likely mainly due to CO2 from fossil fuel We ascribe a large fraction of increasing European summer warmth to human factors Don t blame humans for all weather events and extremes Change over the next 50y+ is already built into climate system Great uncertainty in predictions probabilistic predictions Much of the impact will be felt in the incidence of extreme weather Broadcast Meteorologists must help to get the message across to all of society.