[en] This paper is a synthesis of the first meeting of the Work group on the role of auctions in the European emission trading system. Some lessons learned from the use of this system have been identified: the most efficient auctioning procedures are not necessarily the easiest to implement, this efficiency largely depends on the implementation details (auction mechanism, implementation timing, actors' economical power and attitude, etc.), and there are few directly comparable experiments of such a use of auctioning. Some recommendations are given on the periodicity of auctions and the possibility of using non competitive auction mechanisms for small actors. Some other issues have been discussed: the impact of an auction allocation on the marginal cost, the impact of auctions on the quota system dynamics, the impact of auctions on the assessment of the CO₂ cost at all management levels, the possibility of recycling auction incomes

[en] The authors propose innovating options enabling political, technological and financial cooperation, for a better negotiation on climate. They identify nine issues: defining a constraining legal and institutional framework which will preserve Kyoto's assets, defining a long term objective (by 2050), implementing credible actions and realistic national commitments, strengthening of carbon markets, defining precisely the role of credit systems, establishing a specific agreement on avoided deforestation, paying particular attention to adaptation, developing means of coordination on technologies, and implementing sector agreements

[en] This project aimed at studying the influence of climate change, in relationship with changes of direct anthropic constraints, on the water resource in the Seine river basin. It is not limited to hydrological aspects of climate change, but also aims at analysing direct and indirect consequences of climate modifications on the bio-geochemical quality of the hydro-system (nutriments including nitrates, oxygen, eutrophication, and so on). The authors show that climate change results in an increased mineralisation of soil nitrogen which comes with an increase of nitrate flows from the soil towards water tables, and of nitrate concentration in these tables which will be higher in 2100 than the drinkability standard in a large fraction of aquifers. The authors also simulated the impact of 3 families of scenarios of constraints of the hydro-system (climate change, agriculture, point releases) on the bio-geochemical quality of the Seine river.

[en] To explore the evolution of a human impacted river, the Seine (France), over the 21st century, three driving factors were examined: climate, agriculture, and point source inputs of domestic and industrial origin. Three future scenarios were constructed, by modification of a baseline representative of recent conditions. A climate change scenario, based on simulations by a general circulation model driven by the SRES-A2 scenario of radiative forcing, accounts for an average warming of + 3.3 deg. C over the watershed and marked winter increase and summer decrease in precipitation. To illustrate a possible reduction in nitrate pollution from agricultural origin, a scenario of good agricultural practices was considered, introducing catch crops and a 20% decrease in nitrogen fertilisation. Future point source pollution was estimated following the assumptions embedded in scenario SRES-A2 regarding demographic, economic and technologic changes, leading to reductions of 30 to 75% compared to 2000, depending on the pollutants. Four models, addressing separate components of the river system (agronomical model, hydrogeological model, land surface model and water quality model), were used to analyse the relative impact of these scenarios on water quality, in light of their impact on hydrology and crop production. The first-order driving factor of water quality over the 21st century is the projected reduction of point source pollution, inducing a noticeable decrease in eutrophication and oxygen deficits downstream from Paris. The impact of climate change on these terms is driven by the warming of the water column. It enhances algal growth in spring and the loss factors responsible for phytoplankton mortality in late summer (grazers and viruses). In contrast, increased seasonal contrasts in river discharge have a negligible impact on river water quality, as do the changes in riverine nitrate concentration, which never gets limiting. The latter changes have a similar magnitude under the three scenarios. Under climate change, riverine and groundwater nitrate concentrations increase and crop production is advantaged with reduced growing cycles and increased yields. In contrast, nitrate concentrations decrease under the good agricultural practices scenario, with a limited decrease in crop production. When these two scenarios are combined, the changes in nitrate concentrations balance each other and crop yields increase. The results of this numerical exercise indicate that the potential changes to the Seine River system during the 21st century will not lead to severely degraded water quality

[en] Global environmental and climate conditions fluctuate on all kind of spatio-temporal scales. Some fluctuations or change/trends are not only anthropogenic, but have different regional and national signatures. While the frequency of extreme events on smaller scales is changing, the public sector and general opinion become more and more aware and concerned of local impacts from global environmental and climate changes. Indeed, negative effects and feedbacks, might occur on ecosystems, natural resources, buildings and grounds, superstructures, economies, food security, public health. This is how, during 1999, a concerted French initiative led to the research program 'Management and Impacts of Climate Change' (GICC). GICC is essentially managed by the Ministry of Ecology and Sustainable Development in close collaboration with the Inter-Ministerial Mission on Greenhouse Effect (MIES). GICC started in 1999. Its first phase (1999-2006) included four calls for proposal (1999, 2000, 2001, and 2002). In parallel and in 2003-2004, the MIES has been developing the so-called 'Climate Plan' based upon three principles : Insure that France follows agreements from the 'Kyoto Protocol'; Participate in ways and means leading to reduction of greenhouse gases by 75% in 2050; Allow for reduction of pollution from transportation means. Input from GICC Phase One final reports are contributing to 'Climate Plan'. The eight themes proposed by GICC-1 (1999-2002) are as follows: Theme 1: Evolution scenarios of the average and extreme features of the 21. Century climate; Theme 2: Interactions between climate, economy and society; related timescales; Theme 3: Role of carbon forest uptake and agricultural practices on climate policies; Theme 4: Links between national and international activities; Theme 5: Towards new inventories of GHG and aerosols (direct and indirect) emissions; Theme 6: Impacts on terrestrial biosphere; Theme 7: Impacts on hydro-systems; Theme 8: Impacts on public health. A symposium presenting the available results of the GICC first phase has taken place in MEDD, Paris, November 23-24, 2004. A final presentation workshop of the first phase took place in Paris, on May 11-12, 2006. This document is the proceedings of this scientific restitution seminar. It is organized in 9 sessions which follow the 8 themes listed above plus a round table for the status and perspectives of the GICC program. (J.S.)