The Human Impacts Database

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

Annual Northern Hemisphere sea ice extent loss

WaterCryosphere

This quantity is a single measurement of the quantity at a given point in time (1979-2021).

Value:

This is equivalent to...

-5.41 × 104 km2 / yr

-3.98 × 1010 m2 / yr at yearly maximum cover (March)

-3.98 × 104 km2 / yr at yearly maximum cover (March)

-8.13 × 1010 m2 / yr at yearly minimum cover (September)

-8.13 × 104 km2 / yr at yearly minimum cover (September)
HuID: 47740
Relevant Year(s): 1979-2021
Summary: This entry represents the annualized trend of sea ice extent lost from the Northern Hemisphere from 1979-2021. The entry gives three values calculated for different periods: 1) the annualized trend for the yearly sea ice extent change, 2) the annualized trend for the sea ice extent change in the month of maximum average extent over the period 1979-2021 (March), and 3) the annualized trend for the sea ice extent change in the month of minimum average extent over the period 1979-2021 (September).
Method: The Sea Ice Index provides satellite data for sea ice cover described as sea ice extent (calculated by taking the integral sum of the areas within grid cells with > 15% ice concentration) and area (calculated by multiplying the percentage of sea ice in each grid cell with > 15% ice concentration by the area of the grid cell and taking the integral sum of these products) in the northern and southern hemispheres from 1979-2021. This entry represents sea ice extent. The annualized yearly trend provided represents the linear trend calculated from the average annual extent. The annualized monthly trends for March and September represent the linear trends calculated from the average monthly extent in the respective months.
Source: Fetterer, F., K. Knowles, W. N. Meier, M. Savoie, and A. K. Windnagel. 2017, updated daily. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: https://doi.org/10.7265/N5K072F8. [2022-Feb-16]. Sea_Ice_Index_Monthly_Data_by_Year_G02135_v3.0.xlsx. (2017)
Dataset: This file gives the calculated linear trend of annualized sea ice extent loss for each month from 1979-2019. (northern_hemisphere_extent_change.csv)
regional resolution
Original Data License: NSIDC Open Data Policy
Added By: nsarai