Comment 1 for bug 1157224

To make a contour map with QGS and Mbtiles:

http://mapbox.com/blog/contour-lines-density-mapping/

first interpolate the points to a raster, then create a contour map.
Next import the contour shapefile into tilemill and style.

Unfortunately, this data is not well represented along with a vector hazard map. This is because the interpolation pixel resolution must be low when interpolating the global data, and thus the contours do not closely follow the source data.

I would like to further investigate this, but instead on interpolation and rasterization, I believe a better result can be achieved using the QGIS contour plugin.