Descriptive Statistics of Multi Model Data

In the paper by Lobell and co-authors (Lobell et al. 2008) an analysis aimed at prioritizing adaptation needs among 12 regions with currently marginal food security is based on climate projections from a CMIP3 ensemble of 20 models. Their simulations of temperature and precipitation change by 2030 under three alternative emission scenarios are extracted and averaged over each region. The empirical distribution of the models' signals of temperature and precipitation change is then sampled and the pairs of temperature and precipitation change are used as input of a statistical model of climate change impacts on crop yield for several basic crops, chosen because they are staples of the hungry's diet in each region.

The median projected impact of climate change on an important crop's production by 2030 and the 5th and 95th percentiles of the distribution of estimated impacts are used as indicators to form a measure of the vulnerability of the region (together with an assessment of the importance of the crop itself in the diet of the region's population). Since in the paper uncertainties in climate changes for the crop regions were quantified by randomly selecting joint changes in temperature and precipitation from the untouched population of models/scenarios projections, and feeding them through the estimated coefficients of the crop regression model (uncertainty in the crop regression model were also addressed by a bootstrap technique), this approach is an example of the one-model-one-vote approach, equally weighting projections from the

20 GCMs. The easy interpretability of the results for a multi-disciplinary audience is one desirable aspect of the analysis, trading off for more sophisticated approaches at combining projections into formal probability distribution functions.

Renewable Energy 101

Renewable Energy 101

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.

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