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 (2017) is reported.


Value:		≈ - 0.5 W / m²
HuID:		85211
Relevant Year(s):		2017
Summary:		Evolution of Earth's albedo obtained from observations of the earthshine for the period 1998-2017. Observations are from the Big Bear Solar Observatory. The data show a climatologically significant ≈ 0.5 W/m² decline in the global albedo over the two decades of data, which means that the Earth absorbs that much more energy from the Sun compared to 1998. For comparison, total anthropogenic forcing led to a ≈ 0.6 W/m² increase in shortwave energy absorption over the same period.
Method:		The reflectance of the Earth is measured by observing the earthshine (i.e., sunlight reflected by the earth that illuminates the dark part of the moon) using modern photometric techniques to precisely determine changes in terrestrial albedo from earthshine. The reported values in the time series are centered about the 1998-2017 mean, and the uncertainties reflect the earthshine measurement error bars.
Source:		Goode, P. R.; Pallé, E.; Shoumko, A.; Montañes-Rodriguez, P.; Koonin, S.E. Earth's Albedo 1998–2017 as Measured From Earthshine. Geophysical Research Letters (2021)
Dataset:		Albedo anomaly for the 1998-2017 period from earthshine observations (earthshine_data.csv) global resolution
Trend:
Original Data License:		CC-BY-NC 4.0
Added By:		ilopezgo