What do we know and what do we guess? Manfred Grasserbauer * Vienna University of Technology * Director Institute for Environment and Sustainability, Joint Research Centre, European Commission (Ispra) 2002-2007 1
Public Perception January 1989 April 2007 2
Evolution of GHG Emissions The concentrations of Green House Gases CO 2 (forcing factor 1), N 2 O (forcing factor 300) and CH 4 (forcing factor 25) increased due to fossil fuel consumption, agriculture and land use changes from 280 to 430 ppm CO 2 e (weighted sum of all GHGs) since preindustrial times. Source: IPCC Fourth Assessment Report 2007 3
Evolution of Global Temperatures Mean surface temperatures according to different reconstructions over 2000 years. Temperature is believed to have been relatively stable before 1850, with regionallyvarying fluctuations such as the Medieval Warm Period or the Little Ice Age. 1900-2004: increase by 0,74 +/- 0,18 ºC 4
Causes of Temperature Increase Overall increase by 0,74 +/- 0,18 ºC 1900 1950: variations in natural phenomena (solar radiation and volcanoes) produced most of the warming and had a small cooling effect afterward. 1950 now: most of the temperature increase caused by increasing concentrations of greenhouse gases resulting from burning of fossil fuel and biomass. Source: IPCC Fourth Assessment Report 2007 5
The Green House Gas Effect Large energy flows taking place, which have big fluctuations depending on geographical location, season, daytime Green House Gas effect in relation very small: 1,6 W/m 2 (0,3 % of total energy flow). Greenhouse effect schematic showing energy flows (W/m 2 ) between space, the atmosphere, and earth's surface. 6
Radiative Heating and Cooling Factors Carbon dioxide, methane, nitrogen dioxide, halocarbons, tropospheric ozone and black carbon on snow fields have a warming effect. Stratospheric ozone, aerosols and cloud albedo have a cooling effect. Large uncertainties of the cooling effects of aerosols and cloud albedo. Net anthropogenic forcing is positive (1,6 W/m 2 ), but uncertainty is +/- 50 %. IPCC Fourth Assessment Report 2007 7
Model Calculations of Temperature Increase Range of means: 2,5 ºC IPCC A2 scenario: Under baseline scenarios CO 2 emissions will increase till 2050 by 70 % in industrialized countries and by 250 % by countries in development. Source: IPCC 2007 8
Possible Future Evolution of Global Warming A2 scenario: Further temperature increase of 4 degrees by 2100. Uncertainties still considerable: Range from 2,4 6,4 ºC. Source: IPCC Fourth Assessment Report 2007 9
Climate Change: EU Policy Reducing climate change risk by MITIGATION ADAPTATION + reducing & avoiding GHG emissions reducing exposure & vulnerability at the lowest cost & greatest benefit. Mitigation goal: limit global warming to 2 C = maximum 550 ppm CO 2equ Kyoto Protocol and Post-2012 Integrated Climate and Energy Policy. 10
Global Mitigation Measures To stabilise the GHG concentrations at 550 ppm CO 2 e a global emission reduction of 50 % by 2050 is required (rel. 1990). Source: The 2 ºC Target, European Commission 2008 11
The Third Industrial Revolution Without a massive technology change these ambitious green house gas reduction targets will NOT be achieved. Global cooperation and substantial policy guidance with initial financial stimulation necessary. Hans Joachim Schellnhuber, Director Potsdam Institute for Climate Change Impact Assessment and Advisor to the Commision President José Manuel Barroso and German Chancellor Angela Merkel on Climate Change matters: We need the Great Transformation based on a reinvention of our industrial metabolism. 12
The Third Industrial Revolution Source: JRC-IES 13
Stopping Deforestation Deforestation in Amazonia: Man-made fires around the Xingu National Park in northeast Brazil. 12 th July 2007
Climate Change: Systems Analysis for Impact Assessment Source: Withgott and Brennan: Environment, Pearson 2008 15
Climate Change: What do we know and what do we guess? Nobel Laureate Paul Crutzen: In regard to predicting the future we are in terra incognita. Source: 16 3DNWorld web-site
Thank you very much for your attention! Disclaimer: While this presentation reflects current EU policies, it does not represent an official statement of the European Commission. 17
Effects of Global Warming Glacier 1900 Glacier retreated 2000 m since 1900. M. Grasserbauer Eco&SD Climate Change Effects: Morteratsch-Glacier (Pontresina, Engadin). 2009 18
Effects of Global Warming Source: ESA Change in Arctic Sea Ice: In M. Sept. Grasserbauer 2007 satellites Eco&SDhave shown the lowest19 sea ice cover in the Arctic. North-West 2009 passage was open for several weeks.
Likely Impacts - Extreme Weather Events Modelling of Regional Changes: Possible Temperature and Precipitation Changes according to IPCC A2 Scenario. Source: Prudence Project 20
Likely Impacts - Droughts European Soil Moisture Maps: Evolution during last 40 years wet normal dry 21 Source: JRC-IES/ECMWF
Likely Impacts - Floods Increased flooding: almost everywhere Decreased extreme floods: Southern Sweden, Finland, Russia, Lower Danube (decreased snowmelt?) Possible changes in river discharge for extreme floods due to climate change. 22 DMI-HIRHAM A2 scenario (12km) with LISFLOOD model. Source: JRC-IES/DMI