Geo-ethics: Past and Future Climate Variations and Changes. Τhe Temperatures of the Past Are Continuously Changing

2020 ◽

Vol 7 (1) ◽

Author(s):

Masayoshi Ishii ◽

Nobuhito Mori

Keyword(s):

Risk Assessment ◽

Global Warming ◽

High Resolution ◽

Climate Changes ◽

Future Climate ◽

Atmospheric Models ◽

Large Ensemble ◽

Past Climate ◽

The Past ◽

Climate Simulations

Abstract A large-ensemble climate simulation database, which is known as the database for policy decision-making for future climate changes (d4PDF), was designed for climate change risk assessments. Since the completion of the first set of climate simulations in 2015, the database has been growing continuously. It contains the results of ensemble simulations conducted over a total of thousands years respectively for past and future climates using high-resolution global (60 km horizontal mesh) and regional (20 km mesh) atmospheric models. Several sets of future climate simulations are available, in which global mean surface air temperatures are forced to be higher by 4 K, 2 K, and 1.5 K relative to preindustrial levels. Nonwarming past climate simulations are incorporated in d4PDF along with the past climate simulations. The total data volume is approximately 2 petabytes. The atmospheric models satisfactorily simulate the past climate in terms of climatology, natural variations, and extreme events such as heavy precipitation and tropical cyclones. In addition, data users can obtain statistically significant changes in mean states or weather and climate extremes of interest between the past and future climates via a simple arithmetic computation without any statistical assumptions. The database is helpful in understanding future changes in climate states and in attributing past climate events to global warming. Impact assessment studies for climate changes have concurrently been performed in various research areas such as natural hazard, hydrology, civil engineering, agriculture, health, and insurance. The database has now become essential for promoting climate and risk assessment studies and for devising climate adaptation policies. Moreover, it has helped in establishing an interdisciplinary research community on global warming across Japan.

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Oxygen-isotope record of sea level and climate variations in the Sulu Sea over the past 150,000 years

Nature ◽

10.1038/380234a0 ◽

1996 ◽

Vol 380 (6571) ◽

pp. 234-237 ◽

Cited By ~ 151

Author(s):

Braddock K. Linsley

Keyword(s):

Oxygen Isotope ◽

Sea Level ◽

Climate Variations ◽

Sulu Sea ◽

The Past ◽

Oxygen Isotope Record ◽

Isotope Record

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Pacific Walker circulation variability during the last millennium reconstructed from a network of water isotope proxy records

10.5194/egusphere-egu21-3748 ◽

2021 ◽

Author(s):

Georgina Falster ◽

Bronwen Konecky ◽

Sloan Coats ◽

Samantha Stevenson ◽

Midhun Madhavan

Keyword(s):

Walker Circulation ◽

Future Climate ◽

Extreme Weather Events ◽

Future Climate Change ◽

Specific Information ◽

Last Millennium ◽

Climate Signal ◽

The Past ◽

The Pacific ◽

Global Precipitation

Changes in the strength of the Pacific Walker circulation (PWC) can have a significant impact on global mean surface temperatures, as well as regional temperature, precipitation, and extreme weather events far beyond the tropical Pacific. Understanding PWC variability is therefore important for constraining future climate. But observational records of the PWC are short, and single-site proxy records for changes in the strength of the PWC during the last millennium offer contrasting interpretations. This leaves a critical gap in our understanding of PWC variability on the decadal to centennial timescales relevant to future climate change.Falster et al. (in prep.) demonstrated that the PWC is strongly imprinted in modern global precipitation &#948;18O (&#948;18OP). This relationship arises via multiple complementary mechanisms, including but not limited to ENSO dynamics. We exploit this relationship to reconstruct changes in the strength of the PWC over the past millennium, using six different statistical and machine learning reconstruction methods in conjunction with a globally-distributed network of palaeo-&#948;18OP records (Konecky et al. 2020). Although &#948;18OP from a relatively small number of locations explains a large proportion of PWC variance in the calibration interval, we use a larger network of sites because larger networks are less susceptible to non-stationary teleconnections or non-signal biases than individual sites or smaller networks.&#160;Preliminary results indicate that reconstructed PWC variability is coherent across methods, particularly for the past 400 years. Our reconstructions are also robust to both the calibration window used, and the particular palaeo-&#948;18OP records included in the reconstruction. This provides confidence that our network comprises sufficient proxy timeseries i.e. that we successfully extracted the common underlying climate signal (the PWC) from site-specific information inherent in individual palaeo-&#948;18OP records. Thus, we are confident that our reconstruction of changes in the strength of the PWC through the last millennium is robust, and it will therefore help to constrain the PWC&#8217;s long-term internal variability and sensitivity to external forcing. References:Falster, G. M., B. Konecky, M. Madhavan, S. Coats, S. Stevenson. 2021. &#8220;Imprint of the Pacific Walker circulation in global precipitation &#948;18O&#8221;. In preparation for Journal of Climate.&#160;Konecky, B. L., N. P. McKay, O. V. Churakova (Sidorova), L. Comas-Bru, E. P. Dassi&#233;, K. L. DeLong, G. M. Falster, et al. 2020. &#8220;The Iso2k Database: A Global Compilation of Paleo-&#948;18O and &#948;2H Records to Aid Understanding of Common Era Climate.&#8221; ESSD. https://doi.org/10.5194/essd-2020-5.

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Sir Nicholas John Shackleton. 23 June 1937 — 24 January 2006

Biographical Memoirs of Fellows of the Royal Society ◽

10.1098/rsbm.2011.0005 ◽

2011 ◽

Vol 57 ◽

pp. 435-462 ◽

Cited By ~ 4

Author(s):

Ian Nicholas McCave ◽

Henry Elderfield

Keyword(s):

Carbon Dioxide ◽

Global Warming ◽

Climatic Changes ◽

Future Climate ◽

The Past ◽

Earth’S Climate ◽

Natural Climate ◽

Precise Role ◽

Present Understanding

Nick Shackleton was an international scientist of great renown who fundamentally changed our understanding of how Earth processes work. His research on ancient oceans and climates was both innovative and pioneering, and he clarified the precise role of carbon dioxide in warming and cooling the Earth's climate. His work contributed greatly to our present understanding of the mechanism and causes of global warming. When he began his research, the investigation of past climatic changes was an area of ‘academic’ interest only. Four decades later, his lifetime achievements define the emergence of our understanding of the operation of Earth's natural climate system. This understanding of the past is now central to efforts to predict the future climate we have begun to create. As well as his many scientific accomplishments, Nick Shackleton excelled in another area, that of music, which was almost as important to him as science, and he was a very accomplished clarinet player. In his work he was spirited and curiosity-driven. He let his students and an entire community share in his brilliance and vision.

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