The Human Impacts Database

A collection of useful numbers for quantifying the impacts of the human presence on Earth.

This quantity comes from a time series measurement and the most recent value (2019) is reported.


Value:		0.20 ± 0.10 g / kg
HuID:		73015
Relevant Year(s):		2019
Summary:		The global surface specific humidity change (or anomaly) reflects the specific humidity relative to a 1981-2010 reference period. Specific humidity refers to the ratio of the mass of water vapor to the total mass of a parcel of air. Data were obtained from the HadISDH.blend 1.0.0.2019f dataset.
Method:		The HadISDH blend surface humidity dataset is computed by weighting and combining the HadISDH land and HadISDH marine datasets. Specific humidity is computed from temperature measurements and dew point data taken at stations over land and ICOADS observations from marine stations on ships, buoys, and ocean platforms. The anomalies are calculated with monthly resolution and averaged over 5° gridboxes. The 2 sigma uncertainty estimates represent the combination of sampling uncertainty, regional coverage uncertainty, and measurement uncertainty (which reflects uncertainties in climatology, measurement, and homogeneity adjustment).
Source:		Met Office Hadley Centre HadISDH blend (land and marine) - gridded global surface humidity dataset. (2020)
Dataset:		Contains time-series anomalies of land + marine specific humidity relative to 1981-2010. (HadISDH_specific_humidity_1973-2019.csv) global resolution
Trend:
Original Data License:		OGL 3.0
Added By:		nsarai