\BeginKnitrBlock{rmdnote}<div class="rmdnote">Note that we are using an equal-area projection (EPSG:3035; Lambert Equal Area Europe), i.e., a projected CRS where each grid cell has the same area, here 1000 x 1000 square meters. 
Since we are using mainly densities such as the number of inhabitants or the portion of women per grid cell, it is of utmost importance that the area of each grid cell is the same to avoid 'comparing apples and oranges'.
Be careful with geographic CRS where grid cell areas constantly decrease in poleward directions (see also Section \@ref(crs-intro) and Chapter \@ref(reproj-geo-data)). </div>\EndKnitrBlock{rmdnote}