SEDAC WMS Service
Source: https://sedac.ciesin.columbia.edu/geoserver/wms
Layer ID:
sdei:sdei-global-annual-avg-pm2-5-modis-misr-seawifs-aod-1998-2012_2010-2012
Example of adding a layer to Leaflet:
L.tileLayer.wms("https://sedac.ciesin.columbia.edu/geoserver/wms", {
layers: 'sdei:sdei-global-annual-avg-pm2-5-modis-misr-seawifs-aod-1998-2012_2010-2012',
format: 'image/png',
transparent: true,
opacity: .6,
attribution: "SEDAC"
}).addTo(map);