Thomas Crowley is an expert in the study of past climates – both warm and cold periods – and their relevance to present climate change and future predictions of climate change.
 tel: (919) 681-8228: e: tcrowley@duke.edu

Research focus: History and modeling of past climates; effect of climate change on the biosphere; past carbon-cycle variations; utilization of paleoclimate data to validate climate models and as a reference scale for future climate change projections. Sea level rise.
   
Although climate change models have an inherent degree of uncertainty, they offer sufficient proof that climate change is occurring at an accelerated pace and they underscore the need to act now to mitigate future consequences, Crowley says. Policymakers make decisions all the time without having complete proof, he notes.
   
Crowley also studies Pleistocene oceanography; paleo-ocean modeling; decadal-centennial scale climate variability; climate projections for nuclear waste disposal sites; and climate change and sea level rise in Texas and along the Gulf Coast.

Gabriele Hegerl studies anthropogenic climate change and natural climate
variability, with a focus on developing statistical techniques for climate research.
tel: (919) 684-6167  e: hegerl@duke.edu

Research focus: Hegerl is an expert on the natural variability of climate and changes in climate due to natural and anthropogenic changes in radiative forcing, such as greenhouse warming, and climate effects of volcanic eruptions and solar radiation.
   
Her study of global-scale surface temperature observations shows that the 20th century’s temperature evolution is highly unusual relative to estimates of climate variability, and that greenhouse gas forcing is likely responsible for a large fraction of the 20th century warming. She and her research colleagues are now looking into ways to narrow the uncertainties in their assessment by studying the effect of uncertainties in model simulations of climate change, trying to understand differences in temperature trends at the earth's surface and in the lower troposphere, and assessing if temperature variability of the last millennium is consistent with scientists’ interpretation of climate of the 20th century.

Rob Jackson studies the impact of global warming and climate change on ecosystems; and linkages between human activity and ecological damage.
 tel: (919) 660-7408: e: jackson@duke.edu

Research focus: Ecosystem functioning and feedbacks between
global change and the biosphere. Global carbon cycle. Carbon sequestration. Water cycle. Climate modeling.
  
In his book, “The Earth Remains Forever,” Jackson documents global environmental problems and the increasing rate of species extinction related to human activity and climate change in recent decades, but says there is still time to preserve the natural world.

Susan Lozier is a physical oceanographer who studies North Atlantic ocean currents and their role in global climate change.
tel: (919) 681-8199: e: s.lozier@duke.edu

Research focus: Large-scale ocean circulation. Ocean response to climate change. Exchange between the coastal ocean and the open ocean.
   
Her research – including a paper in the January 2004 issue of Geophysical Research Letters that documents the warming and salinification of Mediterranean waters – has identified subtle changes taking place in North Atlantic waters over the past 50 years. Waters at high latitudes, such as in the subpolar regions, are becoming colder, less salty and slightly less dense, while waters at low latitudes, such as those nearer the equator, are growing warmer, saltier and slightly denser.
   
“If this continues, it could, in theory, disrupt the circulation of North Atlantic currents and cause them to slow or eventually shut down,” Lozier says.

William Schlesinger studies the effects of elevatedCO₂ levels on the environment. His research does not reinforce the optimism of some policymakers who believe trees and soils can naturally absorb the increasing amounts of carbon dioxide produced by industrial and vehicular emissions.
tel: (919) 613-8004: e: schlesin@duke.edu

Research focus: Global environmental change, focusing on chemical changes in the environment, especially soils, that relate to changes in global climate and desertification.
   
Schlesinger’s research rebuts the hypothesis that trees and soils will be able to absorb ever-increasing amounts of carbon dioxide emissions in the air. Instead, he says, a better strategy would be to employ underground carbon sequestration. “It should be relatively easy to capture the CO₂ emitted from point-sources, such as coal-fired power plants, and inject it into the Earth's crust, where it can react with rock materials,” he says. “This would be easier to verify and more permanent than storage in trees and soils, which are subject to human disruptions like forest fires and cultivation. Several analyses suggest that we could use deep injection to capture a large fraction of the CO₂ emitted from electric power plants, which now account for about one-third of our nation's total emissions.”