Constraining the Nineteenth-Century Temperature Baseline for Global Warming

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F86652079%3A_____%2F23%3A00575274" target="_blank" >RIV/86652079:_____/23:00575274 - isvavai.cz</a>

Výsledek na webu

<a href="https://journals.ametsoc.org/view/journals/clim/36/18/JCLI-D-22-0806.1.xml" target="_blank" >https://journals.ametsoc.org/view/journals/clim/36/18/JCLI-D-22-0806.1.xml</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1175/JCLI-D-22-0806.1" target="_blank" >10.1175/JCLI-D-22-0806.1</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Constraining the Nineteenth-Century Temperature Baseline for Global Warming

Popis výsledku v původním jazyce

Since the Paris Agreement, climate policy has focused on 1.5 & DEG and 2 & DEG C maximum global warming targets. However, the agreement lacks a formal definition of the nineteenth-century ,,pre-industrial,, temperature baseline for these targets. If global warming is estimated with respect to the 1850-1900 mean, as in the latest IPCC reports, uncertainty in early instrumental temperatures affects the quantification of total warming. Here, we analyze gridded datasets of instru-mental observations together with large-scale climate reconstructions from tree rings to evaluate nineteenth-century base-line temperatures. From 1851 to 1900 warm season temperatures of the Northern Hemisphere extratropical landmasses were 0.20 & DEG C cooler than the twentieth-century mean, with a range of 0.14 & DEG -0.26 & DEG C among three instrumental datasets. At the same time, proxy-based temperature reconstructions show on average 0.39 & DEG C colder conditions with a range of 0.19 & DEG -0.55 & DEG C among six records. We show that anomalously low reconstructed temperatures at high latitudes are underrep-resented in the instrumental fields, likely due to the lack of station records in these remote regions. The nineteenth-century offset between warmer instrumental and colder reconstructed temperatures is reduced by one-third if spatial coverage is reduced to those grid cells that overlap between the different temperature fields. The instrumental dataset from Berkeley Earth shows the smallest offset to the reconstructions indicating that additional stations included in this product, due to more liberal data selection, lead to cooler baseline temperatures. The limited early instrumental records and comparison with reconstructions suggest an overestimation of nineteenth-century temperatures, which in turn further reduces the prob-ability of achieving the Paris targets.

Název v anglickém jazyce

Constraining the Nineteenth-Century Temperature Baseline for Global Warming

Popis výsledku anglicky

Since the Paris Agreement, climate policy has focused on 1.5 & DEG and 2 & DEG C maximum global warming targets. However, the agreement lacks a formal definition of the nineteenth-century ,,pre-industrial,, temperature baseline for these targets. If global warming is estimated with respect to the 1850-1900 mean, as in the latest IPCC reports, uncertainty in early instrumental temperatures affects the quantification of total warming. Here, we analyze gridded datasets of instru-mental observations together with large-scale climate reconstructions from tree rings to evaluate nineteenth-century base-line temperatures. From 1851 to 1900 warm season temperatures of the Northern Hemisphere extratropical landmasses were 0.20 & DEG C cooler than the twentieth-century mean, with a range of 0.14 & DEG -0.26 & DEG C among three instrumental datasets. At the same time, proxy-based temperature reconstructions show on average 0.39 & DEG C colder conditions with a range of 0.19 & DEG -0.55 & DEG C among six records. We show that anomalously low reconstructed temperatures at high latitudes are underrep-resented in the instrumental fields, likely due to the lack of station records in these remote regions. The nineteenth-century offset between warmer instrumental and colder reconstructed temperatures is reduced by one-third if spatial coverage is reduced to those grid cells that overlap between the different temperature fields. The instrumental dataset from Berkeley Earth shows the smallest offset to the reconstructions indicating that additional stations included in this product, due to more liberal data selection, lead to cooler baseline temperatures. The limited early instrumental records and comparison with reconstructions suggest an overestimation of nineteenth-century temperatures, which in turn further reduces the prob-ability of achieving the Paris targets.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10509 - Meteorology and atmospheric sciences

Projekt

<a href="/cs/project/EF16_019%2F0000797" target="_blank" >EF16_019/0000797: SustES - Adaptační strategie pro udržitelnost ekosystémových služeb a potravinové bezpečnosti v nepříznivých přírodních podmínkách</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2023

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Climate

ISSN

0894-8755

e-ISSN

1520-0442

Svazek periodika

36

Číslo periodika v rámci svazku

18

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

12

Strana od-do

6261-6272

Kód UT WoS článku

001053856600001

EID výsledku v databázi Scopus

2-s2.0-85171892455