scholarly journals Estimates of climatic influence on the carbon cycle

2019 ◽  
Author(s):  
Ian Enting ◽  
Nathan Clisby
Keyword(s):  
Carbon Cycle ◽  
20Th Century ◽  
Regional Climate ◽  
Ice Core ◽  
Ice Age ◽  
Climate Feedback ◽  
Climate Fluctuations ◽  
Hemispheric Temperature ◽  
Pattern Of Variation ◽  
Single Number

Abstract. The influence of climatic change on the carbon cycle is important as part of a CO2-climate feedback loop. However the magnitude of the coupling depends on the timescales involved. We expand on previous analyses of the ice-core CO2 data from the pre-industrial period 1000–1750, extending the analysis into the 20th century. Our results emphasise the limitations of characterising the climate-to-CO2 influence by a single number γ. Even once a time-scale dependence is incorporated, the coldest part of the Little Ice Age seems to reflect different behaviour to that in earlier or later centuries. Different temperature reconstructions appear to capture distinct aspects of pre-industrial climate fluctuations that lacked global coherence. An exploratory study extends the analysis into the industrial period. In this study, most paleo-temperature data fail to fit the plateau (or plateaus) in 20th century ice-core CO2, with one particular reconstruction as an exception. One interpretation of this fit is that although the reconstruction does not closely reflect hemispheric temperature changes, it samples a pattern of variation where the terrestrial carbon exchange is anomalously sensitive to regional climate variations. These various results suggest that this type of empirical study may have limited applicability to the 21st century.

scholarly journals Twentieth-century warming preserved in a Geladaindong mountain ice core, central Tibetan Plateau

2016 ◽  
Vol 57 (71) ◽  
pp. 70-80 ◽  
Author(s):  
Yulan Zhang ◽  
Shichang Kang ◽  
Bjorn Grigholm ◽  
Yongjun Zhang ◽  
Susan Kaspari ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
20Th Century ◽  
North Atlantic ◽  
Regional Climate ◽  
Source Region ◽  
Ice Core ◽  
Ice Age ◽  
The North ◽  
Central Tibetan Plateau ◽  
The North Atlantic

AbstractHigh-resolution δ18O records from a Geladaindong mountain ice core spanning the period 1477-1982 were used to investigate past temperature variations in the Yangtze River source region of the central Tibetan Plateau (TP). Annual ice-core δ18O records were positively correlated with temperature data from nearby meteorological stations, suggesting that the δ18O record represented the air temperature in the region. A generally increasing temperature trend over the past 500 years was identified, with amplified warming during the 20th century. A colder stage, spanning before the 1850s, was found to represent the Little Ice Age with colder periods occurring during the 1470s–1500s, 1580s–1660s, 1700s–20s and 1770s–1840s. Compared with other temperature records from the TP and the Northern Hemisphere, the Geladaindong ice-core record suggested that the regional climate of the central TP experienced a stronger warming trend during the 20th century than other regions. In addition, a positive relationship between the Geladaindong δ18O values and the North Atlantic Oscillation index, combined with a wavelet analysis of δ18O records, indicated that there was a potential atmospheric teleconnection between the North Atlantic and the central TP.

scholarly journals Climate reconstruction since the Little Ice Age by modelling Koryto glacier, Kamchatka Peninsula, Russia

2008 ◽  
Vol 54 (184) ◽  
pp. 125-130 ◽  
Author(s):  
Satoru Yamaguchi ◽  
Renji Naruse ◽  
Takayuki Shiraiwa
Keyword(s):  
20Th Century ◽  
Meteorological Data ◽  
Ice Core ◽  
Kamchatka Peninsula ◽  
Winter Precipitation ◽  
Ice Age ◽  
Equilibrium Line Altitude ◽  
Ice Cap ◽  
Glacier Terminus ◽  
Tree Ring Data

AbstractBased on the field data at Koryto glacier, Kamchatka Peninsula, Russia, we constructed a one-dimensional numerical glacier model which fits the behaviour of the glacier. The analysis of meteorological data from the nearby station suggests that the recent rapid retreat of the glacier since the mid-20th century is likely to be due to a decrease in winter precipitation. Using the geographical data of the glacier terminus variations from 1711 to 1930, we reconstructed the fluctuation in the equilibrium-line altitude by means of the glacier model. With summer temperatures inferred from tree-ring data, the model suggests that the winter precipitation from the mid-19th to the early 20th century was about 10% less than that at present. This trend is close to consistent with ice-core results from the nearby ice cap in the central Kamchatka Peninsula.

A Quantitative Holocene Climatic Record from Diatoms in Northern Fennoscandia

2000 ◽  
Vol 54 (2) ◽  
pp. 284-294 ◽  
Author(s):  
Atte Korhola ◽  
Jan Weckström ◽  
Lasse Holmström ◽  
Panu Erästö
Keyword(s):  
Regional Climate ◽  
Ice Core ◽  
Ice Age ◽  
Calibration Model ◽  
Subarctic Lakes ◽  
Northern Fennoscandia ◽  
Summer Temperatures ◽  
Climatic Record ◽  
Climate Events

A diatom-based calibration model for predicting summer temperatures was developed using climatically sensitive subarctic lakes in northern Fennoscandia. The model was applied to a sediment core from a treeline lake to infer trends in Holocene climate. The record exhibits long-term variations, as well as a series of shorter-term fluctuations on a time scale of centuries. Summers were warmest in the area about 6200 cal yr B.P. and featured distinct cooling episodes around 8300, 7200, 4200, 3000, and 400 cal yr B.P., most of these coinciding with some known climate events (e.g., the 8200 cal yr B.P. event and the Little Ice Age). The similarity of the observed shifts with the pacings of climate events from marine and ice-core records represents evidence for coupled ocean–atmosphere forcing of the regional climate.

scholarly journals Desert dust and anthropogenic aerosol interactions in the Community Climate System Model coupled-carbon-climate model

2011 ◽  
Vol 8 (2) ◽  
pp. 387-414 ◽  
Author(s):  
N. Mahowald ◽  
K. Lindsay ◽  
D. Rothenberg ◽  
S. C. Doney ◽  
J. K. Moore ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Climate Model ◽  
Regional Climate ◽  
Climate Feedback ◽  
Dust Deposition ◽  
Anthropogenic Aerosols ◽  
Anthropogenic Aerosol ◽  
Climate System Model ◽  
Desert Dust ◽  
The Impact

Abstract. Coupled-carbon-climate simulations are an essential tool for predicting the impact of human activity onto the climate and biogeochemistry. Here we incorporate prognostic desert dust and anthropogenic aerosols into the CCSM3.1 coupled carbon-climate model and explore the resulting interactions with climate and biogeochemical dynamics through a series of transient anthropogenic simulations (20th and 21st centuries) and sensitivity studies. The inclusion of prognostic aerosols into this model has a small net global cooling effect on climate but does not significantly impact the globally averaged carbon cycle; we argue that this is likely to be because the CCSM3.1 model has a small climate feedback onto the carbon cycle. We propose a mechanism for including desert dust and anthropogenic aerosols into a simple carbon-climate feedback analysis to explain the results of our and previous studies. Inclusion of aerosols has statistically significant impacts on regional climate and biogeochemistry, in particular through the effects on the ocean nitrogen cycle and primary productivity of altered iron inputs from desert dust deposition.

scholarly journals A 1400-Year Oxygen Isotope History from the Ross Sea Area, Antarctica

1990 ◽  
Vol 14 ◽  
pp. 94-98 ◽  
Author(s):  
P.M. Grootes ◽  
M. Stuiver ◽  
T.L. Saling ◽  
P.A. Mayewski ◽  
M.J. Spencer ◽  
...  
Keyword(s):  
Ross Sea ◽  
Regional Climate ◽  
Ice Core ◽  
Ice Cores ◽  
Local Conditions ◽  
Climate Fluctuations ◽  
Ross Ice Shelf ◽  
Isotope Record ◽  
Highly Correlated ◽  
Sea Area

Four ice cores from the Ross Sea drainage, Antarctica, show patterns of δ18O variations on a time scale of decades to centuries over the last 1400 years without change in the long-term average δ18O. Century scale δ18O fluctuations in the two cores drilled in the Ross Ice Shelf at Station J-9 (82°23′S, 168°38′W, elevation 60 m) are highly correlated (P < 2 × 10−4). The long isotope record (>30 000 a) of the 1978 J-9 core thus represents local conditions over at least 102 m and on time scales of 100 years and longer.Regional correlations between the J-9 δ18O records and those from Ridge BC (82°54′S, 136°40′W, elevation 509 m) and the Dominion Range (85°15′S, 166°10′E, elevation 2700 m) are barely significant (P ≈ 0.05 for J-9 '76 and Dominion Range, 580 to 1400 years ago) or absent. The failure to find clear regional isotope trends related to climate fluctuations may reflect the finding that between 1957 and 1982 the area was in the transition zone between areas with opposite temperature trends, and showed little or no temperature change. The fact that the records nevertheless show significant δ18O fluctuations highlights the need to base regional climate reconstructions on a regional suite of ice-core records.

scholarly journals A 1400-Year Oxygen Isotope History from the Ross Sea Area, Antarctica

1990 ◽  
Vol 14 ◽  
pp. 94-98 ◽  
Author(s):  
P.M. Grootes ◽  
M. Stuiver ◽  
T.L. Saling ◽  
P.A. Mayewski ◽  
M.J. Spencer ◽  
...  
Keyword(s):  
Ross Sea ◽  
Regional Climate ◽  
Ice Core ◽  
Ice Cores ◽  
Local Conditions ◽  
Climate Fluctuations ◽  
Ross Ice Shelf ◽  
Isotope Record ◽  
Highly Correlated ◽  
Sea Area

Four ice cores from the Ross Sea drainage, Antarctica, show patterns of δ18O variations on a time scale of decades to centuries over the last 1400 years without change in the long-term average δ18O. Century scale δ18O fluctuations in the two cores drilled in the Ross Ice Shelf at Station J-9 (82°23′S, 168°38′W, elevation 60 m) are highly correlated (P &lt; 2 × 10−4). The long isotope record (&gt;30 000 a) of the 1978 J-9 core thus represents local conditions over at least 102 m and on time scales of 100 years and longer. Regional correlations between the J-9 δ18O records and those from Ridge BC (82°54′S, 136°40′W, elevation 509 m) and the Dominion Range (85°15′S, 166°10′E, elevation 2700 m) are barely significant (P ≈ 0.05 for J-9 '76 and Dominion Range, 580 to 1400 years ago) or absent. The failure to find clear regional isotope trends related to climate fluctuations may reflect the finding that between 1957 and 1982 the area was in the transition zone between areas with opposite temperature trends, and showed little or no temperature change. The fact that the records nevertheless show significant δ18O fluctuations highlights the need to base regional climate reconstructions on a regional suite of ice-core records.

scholarly journals Desert dust and anthropogenic aerosol interactions in the Community Climate System Model coupled-carbon-climate model

2010 ◽  
Vol 7 (5) ◽  
pp. 6617-6673 ◽  
Author(s):  
N. Mahowald ◽  
K. Lindsay ◽  
D. Rothenberg ◽  
S. C. Doney ◽  
J. K. Moore ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Climate Model ◽  
Regional Climate ◽  
Climate Feedback ◽  
Dust Deposition ◽  
Anthropogenic Aerosols ◽  
Anthropogenic Aerosol ◽  
Climate System Model ◽  
Desert Dust ◽  
The Impact

Abstract. Coupled-carbon-climate simulations are an essential tool for predicting the impact of human activity onto the climate and biogeochemistry. Here we incorporate prognostic desert dust and anthropogenic aerosols into the CCSM3.1 coupled carbon-climate model and explore the resulting interactions with climate and biogeochemical dynamics through a series of transient anthropogenic simulations (20th and 21st centuries) and sensitivity studies. The inclusion of prognostic aerosols into this model has a small net global cooling effect on climate but does not significantly impact the globally averaged carbon cycle; we argue that this is likely to be because the CCSM3.1 model has a small climate feedback onto the carbon cycle. We propose a mechanism for including desert dust and anthropogenic aerosols into a simple carbon-climate feedback analysis to explain the results of our and previous studies. Inclusion of aerosols has statistically significant impacts on regional climate and biogeochemistry, in particular through the effects on the ocean nitrogen cycle and primary productivity of altered iron inputs from desert dust deposition.

Global warming influences dynamics of plague’s epidemic manifestations in XX-XXI centuries

2017 ◽  
pp. 38-40
Author(s):  
E.S. Zenkevich ◽  
N.V. Popov
Keyword(s):  
Global Warming ◽  
20Th Century ◽  
Modern Trend ◽  
Climate Fluctuations ◽  
The World ◽  
Low Incidence ◽  
High Level

During the second half of 20th century, a high level of plague incidence in the world was in 1960–1979 and 1990–2009. The significant decrease of infection cases was in 1950–1959, 1980–1989, 2010–2015. It is noticed, that the observed cyclical nature of the alternation of high and low incidence plague’s periods, in many respects related to modern trend of climate fluctuations.

scholarly journals Late-Holocene diatom community response to climate driven chemical changes in a small, subarctic lake, Northwest Territories, Canada

The Holocene ◽  
2021 ◽  
pp. 095968362110032
Author(s):  
Paul B Hamilton ◽  
Scott J Hutchinson ◽  
R Timothy Patterson ◽  
Jennifer M Galloway ◽  
Nawaf A Nasser ◽  
...  
Keyword(s):  
Iron Age ◽  
Biological Diversity ◽  
Regional Climate ◽  
Natural Aging ◽  
Community Response ◽  
Warm Period ◽  
Ice Age ◽  
Diatom Assemblages ◽  
Subarctic Lake ◽  
Over Time

The paleolimnological record of diatoms and climate, spanning the last 2800 years, was investigated in a small subarctic lake (Pocket Lake) that from AD 1948 to 2004 was contaminated by gold smelting waste. An age-depth model was constructed using a combination of 210Pb, 14C, and tephra to determine a 2800 year history of lake ontogeny (natural aging), biological diversity, and regional climate variability. Diatoms form six strong paleoecological assemblages over time in response to changes in local hydrological and sedimentological conditions (including metals). Selected environmental variables explained 28.8% of the variance in the diatom assemblages, with Fe, Ca, and sediment end member distribution being important indicators. The diatom assemblages correlated to the Iron Age Cold Epoch (2800–2300 cal BP), Roman Warm Period (2250–1610 cal BP), Dark Age Cold Period (1500–1050 cal BP), Medieval Climate Anomaly (ca. 1100–800 cal BP), and the Little Ice Age (800–200 cal BP). The disappearance of Staurosira venter highlights the change from the Iron Age Cold Epoch to the Roman Warm Period. After deposition of the White River Ash (833–850 CE; 1117–1100 cal BP), transition to circumneutral conditions was followed in tandem by a transition to planktic influenced communities. Ten discrete peaks of Cu, Pb, and Zn were observed and attributed to soluble mobility from catchment soils through enhanced seepage and spring snowmelt. The prominent metal spikes were aligned with increases in Brachysira neoexilis. Downward mobilization of arsenic and antimony from contaminated surficial sediments highlight the problem of post depositional industrial contamination of paleosediments. Results demonstrate that paleoclimatic changes in the region, modulated by solar radiation, impacted temperature and precipitation in the lake catchment, influencing temporal shifts in diatom ecology. Changes in diatom taxa richness provided valuable information on the relative influence of water quality (planktic taxa) and sediment input (benthic taxa). The diatom assemblage succession also provides evidence that natural aging over time has played a role in the ecological evolution of the lake.

Ice-Core Pollen Record of Climatic Changes in the Central Andes during the last 400 yr

2005 ◽  
Vol 64 (2) ◽  
pp. 272-278 ◽  
Author(s):  
Kam-biu Liu ◽  
Carl A. Reese ◽  
Lonnie G. Thompson
Keyword(s):  
Little Ice Age ◽  
Ice Core ◽  
Climatic Changes ◽  
Ice Age ◽  
Striking Similarity ◽  
Pollen Record ◽  
Dry Period ◽  
Proxy Records ◽  
Ice Cap ◽  
Ice Accumulation

AbstractThis paper presents a high-resolution ice-core pollen record from the Sajama Ice Cap, Bolivia, that spans the last 400 yr. The pollen record corroborates the oxygen isotopic and ice accumulation records from the Quelccaya Ice Cap and supports the scenario that the Little Ice Age (LIA) consisted of two distinct phases�"a wet period from AD 1500 to 1700, and a dry period from AD 1700 to 1880. During the dry period xerophytic shrubs expanded to replace puna grasses on the Altiplano, as suggested by a dramatic drop in the Poaceae/Asteraceae (P/A) pollen ratio. The environment around Sajama was probably similar to the desert-like shrublands of the Southern Bolivian Highlands and western Andean slopes today. The striking similarity between the Sajama and Quelccaya proxy records suggests that climatic changes during the Little Ice Age occurred synchronously across the Altiplano.

Sign in / Sign up

Export Citation Format

Share Document