The Importance of Understanding the Last Glacial Maximum for Climate Change

[摘要] The last glacial maximum (LGM) at approximately 23–18k (k—thousand calendar years) provides an important contrast to our present and pre-industrial climate in a warming world. Global observational datasets of LGM land and sea surface conditions have been synthesized and present some interesting challenges both for providing another scenario for understanding climate change and for climate sensitivity. These challenges are ongoing, as data increase and modeling improves. By definition, the LGM is defined as the time during the last glacial interval in which maximum ice was sequestered in ice sheets as visible in the marine isotopic records. Maximum cooling is visible from pollen and macrofossil records 14C dated to this interval, and ice sheets and alpine glaciers are roughly at their maximum extent throughout the globe. The ice cores extracted from Greenland and Antarctica have given us high-resolution records of greenhouse gases, dust, and isotopes of hydrogen and oxygen which reveal the progression out of the LGM at 18k as climate warmed.

[发布日期] 2018-03-01

[学科分类] 海洋学与技术

[关键词] AIR COOLING;ANTARCTIC REGIONS;ATMOSPHERIC PHYSICS;CARBON CYCLE;CLIMATE CHANGE;CLIMATE MODELS;EARTH SURFACE;GLACIAL DRIFT;GREENHOUSE EFFECT;ICE;ISOTOPE RATIOS;MOISTURE CONTENT;OCEANS;SEA SURFACE TEMPERATURE;SURFACE COOLING;SURFACE PROPERTIES;THERMOHALINE CIRCULATION;TROPICAL REGIONS