Some databases also include example code for extracting data.
Worldclim: https://www.worldclim.org/
Example publication here: https://www.pnas.org/doi/10.1073/pnas.2216789120
Includes: temperature and rainfall (averages, variation, minimums, maximums)
library(raster)
library(geodist)
climdata <- getData('worldclim',download=TRUE,var='bio',res=5)
sample.coord <-read.table("metadata_au.txt", header=T, stringsAsFactors=F)
points_D3 <- SpatialPoints(sample.coord[,2:3], proj4string=climdata@crs) #coordinated provided are Long, then Lat
values_D3 <- extract(climdata,points_D3)
CHELSA: https://chelsa-climate.org/
Example publication here: ??
Includes: ca. 1km resolution, downscaled future projections (generally better than raw ones), and also has stuff like growing degree days, growing season length (BIOCLIM+). CHELSA's grid cells are shifted from others by half a grid cell.
CRU: https://crudata.uea.ac.uk/cru/data/hrg/
Example publication here: ??
Includes: This is climate data at 0.5 degrees. Used a lot in climate modelling as baselines, etc. I think is available from 1901. Probably more appropriate for larger spatial scale modelling. I cannot remember the temporal resolution, but data likely available from monthly to 30 year climatologies.
WFDEI: https://data.ucar.edu/dataset/the-wfdei-meteorological-forcing-data
Example publication here: ??
Includes: Similar to CRU, but is climate model outputs "forced" with some data, it is available at 3-hourly to 30 year climatology from 1979-2016, also at 0.5 degrees resolution. Maybe some newer versions now.
Tree cover percentage: https://globalmaps.github.io/ptc.html
Example publication here: ??
Includes: there is probably new MODIS data, but not at 1km (at higher resolution)
Light at night global radiance (NOAA Global Radiance Calibrated Nighttime Lights): https://ngdc.noaa.gov/eog/dmsp/download_radcal.html
Example publication here: https://www.pnas.org/doi/10.1073/pnas.2216789120
Includes: Night time illumination levels across the globe
SEDAC population density: https://sedac.ciesin.columbia.edu/data/set/popdynamics-1-km-downscaled-pop-base-year-projection-ssp-2000-2100-rev01/data-download
Example publication here: ??
Includes: ca. 1km resolution, human population, total, "rural", and "urban", with future projections based on a few different socio-economic scenarios (SSP)
SEDAC urban land extent: https://sedac.ciesin.columbia.edu/data/set/ssp-1-km-downscaled-urban-land-extent-projection-base-year-ssp-2000-2100
Example publication here: ??
Includes: ca. 1km resolution, urban land extent
Hyde (History database of the Global Environment): https://www.pbl.nl/en/hyde-history-database-of-the-global-environment
Example publication here: ??
Includes: HYDE covers the whole Holocene. HYDE is and internally consistent combination of updated historical population (gridded) estimates and land use for the past 12,000 years. Categories include cropland, with a new distinction into irrigated and rain fed crops (other than rice) and irrigated and rain fed rice. Also grazing lands are provided, divided into more intensively used pasture, converted rangeland and non-converted natural (less intensively used) rangeland. Population is represented by maps of total, urban, rural population and population density as well as built-up area.
Human Phenotype Ontology: https://hpo.jax.org/app/
Example publication here: https://www.pnas.org/doi/10.1073/pnas.2216789120