Agricultural management effects on mean and extreme temperature trends
Understanding and quantifying land management impacts on local climate is important for distinguishing between the effects of land management and large-scale climate forcings. This study for the first time explicitly considers the radiative forcing resulting from realistic land management and offers...
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Published in | Earth system dynamics Vol. 13; no. 1; pp. 419 - 438 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Gottingen
Copernicus GmbH
23.02.2022
Copernicus Publications |
Subjects | |
Online Access | Get full text |
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Summary: | Understanding and quantifying land management impacts on local climate is
important for distinguishing between the effects of land management and
large-scale climate forcings. This study for the first time explicitly
considers the radiative forcing resulting from realistic land management and
offers new insights into the local land surface response to land management.
Regression-based trend analysis is applied to observations and present-day
ensemble simulations with the Community Earth System Model (CESM) version 1.2.2 to assess the impact of irrigation and conservation agriculture (CA)
on warming trends using an approach that is less sensitive to temperature
extremes. At the regional scale, an irrigation- and CA-induced acceleration
of the annual mean near-surface air temperature (T2m) warming trends
and the annual maximum daytime temperature (TXx) warming trends were
evident. Estimation of the impact of irrigation and CA on the spatial
average of the warming trends indicated that irrigation and CA have a pulse
cooling effect on T2m and TXx, after which the warming trends increase
at a greater rate than the control simulations. This differed at the local
(subgrid) scale under irrigation where surface temperature cooling and the
dampening of warming trends were both evident. As the local surface warming
trends, in contrast to regional trends, do not account for atmospheric
(water vapour) feedbacks, their dampening confirms the importance of
atmospheric feedbacks (water vapour forcing) in explaining the enhanced
regional trends. At the land surface, the positive radiative forcing signal
arising from enhanced atmospheric water vapour is too weak to offset the
local cooling from the irrigation-induced increase in the evaporative
fraction. Our results underline that agricultural management has complex and non-negligible impacts on the local climate and highlight the need to
evaluate the representation of land management in global climate models
using climate models of higher resolution. |
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ISSN: | 2190-4987 2190-4979 2190-4987 |
DOI: | 10.5194/esd-13-419-2022 |