I would like to create a polygon with (roughly) one third (or any other fraction) of the worlds surface.
I assume I should use an equal area projeciton like Lambert cylindrical equal-area, robinson or maybe mollweide.
What I did (in R) was the following.
I went to epsg.io, grabbed the extents of the robinson-projection (54030) and did this:
world_bb = c(-17005833.33, -8625154.67, 17005833.33, 8625154.67) %>% setNames(c("xmin", "ymin", "xmax", "ymax")) %>% st_bbox() %>% st_as_sfc() %>% st_as_sf(crs="+proj=robin +lon_0=0 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs +type=crs") world_area_sqkm = st_area(world_bb) %>% units::set_units("km^2") world_area_sqkm #586711771 [km^2]
Google tells me that the world has a surface area of 510 million square kilometers.
Also, when I reproject that bounding box to 4326 to plot it on a web map I get this:
world_bb_4326 = st_transform(world_bb, 4326) mapview(world_bb_4326)
Does anyone have any idea on how to do that better using R?