powering our future with weather, climate and water a large part of my presentation will address...
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Powering our future with weather, climate and water
A large part of my presentation will address Extreme events A few words on the meeting organized yesterday (FIM) Global warming : an overview (IPCC AR4).
Weather forecasts and hydrological information are a part of daily life in industrial countries but are largely absent from developing countries
Development, climate and hydro-met services Health and disaster risk reduction Industry and Energy Agriculture and Water How to develop sustainable hydro-met services ?
1) Human activities are modifying the composition of the atmosphere in greenhouse
gases (important and rapid)
IPCC 2007 : we are certain of2) Warming is uniquevocal
Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.
Numerous uncertainties remain
Carbon dioxide + 39 %Methane +150 %Nitrous oxide + 20%
3) Warming will continue
2010
Temperature difference between 2010 /1970 (Hansen et al., 2011)Average global warming de 0.66 ° ; more than twice in the Arctic
A1B is a typical « business asusual scenario »At the end of the century (2090 – 2099),
the projected global warming is of 2.8°C (average value)Much of land areas warms by ~ 3°5 C ; Arctic warms about 7°C ;
less if less emissions ; more if more emissions
Our activities have little influence on the climate of the coming decade
B1983 GtC
A1B 1499 GtC
A21862 GtC
2.8°C1.7 - 4.4
But the climate at the end of this century depends on our activities
1.8°C1.1 - 2.9
3.4°C2.0 - 5.4
Numerous impacts :• more frequent heatwaves• increased risk of droughts in some regions• increase risk of floods in other regions• more intense precipitaion events• risk of more intense cyclones• sea-level rise, permafrost melting• ocean acidification, ecosystems, health• agriculture, tourism, infrastructures…
Précipitations
Winter Summer
Temperatures
Numerous uncertainties :• emission scenarios• importance of global warming• regional characteristics, précipitation• clouds, aerosols• evolution of ice sheets • climatic surprises• ……..
Between 20 and 60 cm unti 2100, may be moreRisk of a few meters in a few centuries
Deltas
World population should rapidly increase in coastal areas with increasing risks linked with sea-level rise
Natural causes(solar activity, volcanoes)
Observations
Anthropogenic activitiesGreenhouse gases and aérosols natural
causes
Most of the observed increase in global average temperature since the mid-20th century is very likely due to
the observed increase in anthropogenic greenhouse gas
concentration
Have human activities already affected our climate?
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