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Explore the impact of the greenhouse effect on Earth's climate system, human-induced emissions of greenhouse gases, and the changing climate trends affecting the Mediterranean region. Learn about regulations on energy efficiency for ships and the evolving challenges for the maritime industry.
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Outline • The greenhouse effect and the Earth’s climate system • The …human element in climate: Emissions of greenhouse gases • How is climate changing? • Impacts • Climate change and the Mediterranean • Regulations on the energy efficiency of ships
The greenhouse effect and the Earth’s climate system
The greenhouse effect About 30% of the incoming solar radiation is directly reflected by the atmosphere (clouds, dust particles, aerosols) and the earth surface Trace gases in the earth’s atmosphere (greenhouse gases) re-absorb most of the outgoing infrared radiation and sent it back to earth. The rest 70% is absorbed by the atmosphere, oceans and land All components of the earth system are heated by the absorbed energy and emit part of it as long-wave (infrared) radiation. Natural GHGs Carbon Dioxide CO2 Methane CH4 Nitrous Oxide N2O Water Vapour H2O
The Earth without the greenhouse effect The Earth thanks to the greenhouse effect Average temperature -18 oC Average temperature 14 oC The Earth with enhanced greenhouse effect Average temperature >14.5 oC (so far…) The greenhouse effect: too much of a good thing…
Global distribution of solar energy input Mean annual global insolation
Redistributing heat throughout the globe: the global ocean conveyor belt…
Climate changes constantly over various timescales due to natural variability… Temperature change from present, oC Source: NOAA
The …human element in climate: Emissions of greenhouse gases
Human-induced increases in GHGs Source: World Meteorological Organization (WMO)
CO2 (ppm) Human-induced increases in GHGs Source: World Meteorological Organization (WMO)
CH4 (ppb) Human-induced increases in GHGs Source: World Meteorological Organization (WMO)
N2O (ppb) Human-induced increases in GHGs Source: World Meteorological Organization (WMO)
Human-induced increases in GHGs Source: World Meteorological Organization (WMO) Source: World Meteorological Organization (WMO)
The human element… Model simulations show clearly that temperature increase since 1950 is induced by human activities
26% 74% (thousands tones) (thousands tones) Sources of CO2 emissions Power production, industrial activities, transports Changes in land use, deforestation, urbanization
870 million tones CO2 emissions per sector (2007) Source: Second IMO GHG Study 2009
Melting of glaciers, retreat of sea ice and sea level rise… Alaska, Muir Glacier 13 August 1941 31 August 2004
Source: IPCC Blue bars: change between 1961 – 2003 Red bars: change between 1993 - 2003 Marine environment and climate change • Warming (up to 3000 m depth) • Changes in salinity • Disturbance of ocean currents (conveyor belt)
Marine environment and climate change • Warming (up to 3000 m depth) • Changes in salinity • Disturbance of ocean currents (conveyor belt) • Acidification
Marine environment and climate change CO2 + H2O H2CO3 H2CO3 H+ + HCO3- H+ + CO32- HCO3- CaCO3 Ca2+ + CO32-
Marine environment and climate change • Habitat losses • Coral bleaching • Changes in the life cycle and distribution of many species, increased risk of species invasions, biodiversity losses
Marine environment and climate change • Changes in wind conditions, average wave height, sea ice coverage, sea level etc. have serious implications for shipping and related infrastructure.
As a general trend, over the last decades Mediterranean climate has become progressively hotter and drier Average summer temperature has increased up to 3 οC Average winter precipitation has decreased by 20%
As a general trend, over the last decades Mediterranean climate has become progressively hotter and drier Droughts, summer heat waves and fires have increased both in frequency and intensity and are expected to worsen in the near future, resulting in widespread desertification of the area
As a general trend, over the last decades Mediterranean climate has become progressively hotter and drier Lack of freshwater, especially during the summer period, is a major threat for an area representing less than 3% of the global freshwater reservoir and hosting 50% of the global population already suffering from limited access to water resources.
As a general trend, over the last decades Mediterranean climate has become progressively hotter and drier Meditteranean sea is getting warmer: surface temperatures have increased 0.8 – 1.4 oC and deep water (>250 m) has become 0.12 oC warmer. Changes in circulation are already observed
As a general trend, over the last decades Mediterranean climate has become progressively hotter and drier Warming of sea water favors and accelerates the migration and expansion of introduced species of tropical origin (>600 in the Eastern Mediterranean) northwards and westwards
A glimpse to the future… Climate system is complex… Human society is even more complex… Naturally, projections of future climate change show huge deviations
Shipping is by far the most energy efficient mode of transport… Source: Second IMO GHG Study 2009
But there is still great potential (and need) for improvement… World seaborne trade (billion tonne miles)
Regulations on energy efficiency of ships (new chapter 4 of MARPOL Annex VI) are expected to enter into force on 1 January 2013 Energy Efficiency Design Index (EEDI) new ships over 400 GRT Ship Energy Efficiency Management Plan (SEEMP) all ships over 400 GRT
Energy efficiency design index (EEDI) (grams CO2 / capacity * nautical mile)