Climate Change: What’s natural, what’s human-caused, and how do we know?
August 29th, 2019
Q&A Podcast (49:52):
Mechanisms of Abrupt Extreme Precipitation Change Over the Northeastern United States – journal article referenced in the presentation concerning record rainfall in the lower Northeast
Greenland 2012 recap: https://www.climate.gov/news-features/understanding-climate/summer-2012-brought-record-breaking-melt-greenland
Arctic Report Card 2018: https://www.climate.gov/news-features/understanding-climate/2018-arctic-report-card-visual-highlights
Collecting carbon dioxide data in the Southern Ocean: https://www.climate.gov/news-features/features/first-saildrone-circumnavigates-antarctica-seeking-carbon-dioxide
Sea Level Rise Viewer: https://toolkit.climate.gov/tool/sea-level-rise-and-coastal-flooding-impacts-viewer
Glaciology video from AMNH: https://www.amnh.org/explore/videos/earth-and-climate/archived-in-ice-rescuing-the-climate-record
Primary Productivity, showing southern Ocean, from AMNH: https://www.youtube.com/watch?v=geR2KsF53y4
It is well known that Earth’s climate changes due to natural cycles of various length: from the ice ages to El Nino. We also know conclusively that human emissions of greenhouse gases such as carbon dioxide are causing the Earth’s average temperature to warm rapidly, causing glaciers to melt, sea level to rise, and storm patterns to change. Thus, the climate that we experience at any time results from some combination of natural and human causes. How do climate scientists disentangle these effects to identify the true impact of human activities on climate? We will explore this complex question through case studies focused on extreme storms in the northeast USA and glacial melting in Greenland. This research involves the use of ice cores, weather station data, and the latest global and regional-scale climate models.
Presenter: Dr. Erich Osterberg
Dr. Osterberg’s overarching research objective is to understand how and why climate has changed, and identify trends and sources of air pollution. His specialty is creating long (50-50,000 years) records of climate change and air pollution by analyzing chemical markers preserved in glacier ice cores. He also studies data from weather stations and climate models to determine recent climate trends to differentiate natural cycles from human-caused changes. He is particularly interested in aspects of climate change that impact communities, including sea-level rise from melting glaciers, and the changing number and intensity of storms. He is an associate professor of earth sciences at Dartmouth College.