ACCWW

Overview

Abrupt climate change cannot be understood within the confines of a single discipline and one result of the project on Abrupt Climate Change in a Warming World (ACWW) and its predecessor AbRupt climate CHangE Studies (ARCHES) has been the convergence of researchers from disciplines as diverse as oceanographers and glaciologists. This leads, at the very least, to stimulating discussions and, at best, to novel understanding as a result of cross-disciplinary collaborations. A formal way to bring researchers together is through gatherings, such as the Annual Meeting in July 2009, and workshops on Glaciers in November 2009 and Dust Records for a Changing World in May 2010.

What is Abrupt Climate Change?

The definition of ‘abrupt’ loosely includes nonlinear climate change as well as changes that may be linear but which are of sufficient amplitude and rapidity as to appear ‘abrupt’ to human societies or to other ecosystems that struggle to adapt at that rate.

What is Abrupt Climate Change in a Warming World?

The Abrupt Climate Change in a Warming World (ACWW) project is the latest incarnation of a long running NOAA funded program of integrated research at Lamont into the problem of abrupt climate change. The focus is on (1) climate change in the late Pleistocene and Holocene periods and (2) near term future abrupt change, including social impacts of anticipated change.

ACCWW was conceived at Lamont as a 5 year program but was funded by NOAA for just two years. Below we report on the first annual meeting which brought together Lamont, Columbia and outside experts to discuss a wide range of topics on past and future rapid climate change.  Talks are are linked within the text below.

 

First Annual Meeting

Lamont Doherty Earth Observatory of Columbia University
July 8-10, 2009

Meeting overview: trends in abrupt change research

The meeting revealed some interesting trends in climate change research.

  • In recent years abrupt change research has become increasingly focused on future climate change and has been pushed into the forefront of applied research.  This has largely resulted from observations of dramatic change, such as loss of summer Arctic sea ice, the speed up of Greenland outlet glaciers, ongoing droughts in southwestern North America and other droughts in the Middle East-Central Asia area and Australia, heat waves and destructive hurricanes.
  • These events have provoked intense debate regarding whether they result solely from natural variability or if they have a human-induced component.
  • Based on analysis of data and models, even if without definite proof of the human role, there is ample reason to be deeply concerned by the trajectory on which greenhouse gas emissions have set the world’s climate.
  • Climate research needs to play catch-up as the several mechanisms, such as sea ice loss, ice sheet mass loss, subtropical drying, changes in frequency and intensity of tropical storms, monsoon response to radiative forcing, are at best partly understood even as change occurs before our eyes.
  • Reliable and truly useful predictions of future climate change require a much better understanding of the basic climate dynamics processes, and improved ability to capture these in models.
  • This improved understanding requires much longer climate records than the instrumental period provides.  Long records are the only access to the full range of natural variability of the climate system.  Faith in climate model predictions will come only by demonstrating that these same models can replicate the dramatic changes that have occurred in the Pleistocene and Holocene periods.
  • The back and forth between workers in such disparate areas of climate research highlights  the usefulness of integrated climate system research which allows a productive cross pollination of fresh ideas and perspectives.

» Presentation summaries and downloads are available here.

DUSTSPEC Workshop 2010

Lamont Doherty Earth Observatory of Columbia University
May 24-26, 2010

Meeting Overview

Columbia University’s Lamont-Doherty Earth Observatory (LDEO) hosted a conference on dust in the climate system from May 24 to May 26, 2010. The conference was jointly supported by the National Oceanic and Atmospheric Administration-funded Abrupt Climate Change in a Warming World (ACCWW) project and the International Union for Quaternary Research (INQUA). Gisela Winckler  of LDEO, Natalie Mahowald of Cornell University and Barbara Maher of Lancaster University collectively organized the conference.

Mineral dust plays an important role in the climate system, both by affecting the radiative balance of the atmosphere and by affecting biogeochemical cycling. During Earth’s history, dust has been strongly linked with climatic conditions: ice cores and marine sediments tell us that the ice age world was much dustier than today’s. Therefore, dust is both a driver and a passive recorder of climate change under different climatic regimes of Earth’s past. However, its exact role in past climate change remains poorly understood. Clearly defining the links between dust and climate in the past is critical in evaluating future impacts of dust on Earth’s climate system in a warming world.

Because dust affects and interacts with the climate system in so many different ways, a wide range of disciplines—atmospheric modeling, paleoclimatology, geology, ice core science, biogeochemistry, chemical oceanography, and many others – is required in order to evaluate its role and impact.

The major goal of the DUSTSPEC workshop was to instigate design of the next generation of a dust data compilation that would incorporate dust time-series data from a variety of climate archives over the whole of the last glacial-interglacial cycle.

About 40 participants, representing various subdisciplines of dust research, convened for two and a half days for a series of presentations, a poster session and several break out groups and plenary sessions. The lively interaction at the workshop between observationalists and modelers from such diverse backgrounds highlighted the usefulness of integrated dust/climate system research, particularly crossing the boundaries between the paleo and modern dust communities, which allows a productive cross fertilization of ideas and perspectives.

» Presentation summaries and downloads are available here.