Climate risks for the Midwestern USA
Abstract
The Midwest comprises about 20% of the US population, contributes 20% of the national gross domestic product, plays a key role in the nation's food production and is home to a number of major urban centers and critical infrastructure. In 2011, eleven of the record fourteen weather-related disasters with damages of over $1 billion in the United States affected the Midwest, and 2012 has seen widespread drought that have devastated yields of essential agricultural crops. In this presentation, we briefly summarize key vulnerabilities within the region and document adaptation steps that have been and are being taken to enhance resilience. Based on the current literature and robust projections for key climate-relevant metrics defined using historical data and computed primarily from output of the NARCCAP simulations, our major findings are as follows: 1) In the short term, longer growing seasons and rising carbon dioxide levels will tend to increase certain crop yields. However, in some cases, those benefits will be offset by increased occurrence of extreme events such as heat-waves, droughts and floods. 2) The species composition of natural ecosystems is expected to change as habitats for many tree species shift northward. The role of the regions forests as a net sink of carbon is at risk from the combined effect of multiple stressors. 3) Increased heat wave intensity and frequency, degraded air quality, and reduced water quality will increase public health risks. For example, there is evidence that in the absence of major mitigation efforts, the frequency of days in Chicago with temperatures in excess of 90 deg F will double by the middle part of this century. 4) The Midwest has a highly energy-intensive economy and emits a disproportionately large amount of heat-trapping gases. It also has a large, and increasingly realized, potential to reduce emissions that cause climate change. Energy infrastructure in the region is vulnerable to increased demand (e.g., the Midwest Independent System Operator of the electricity distribution network experienced record peak demand during summer 2012), especially if coupled with reduced cooling water availability or increased water temperatures. Such events led to partial curtailment of facilities during summer 2012. 5) Extreme rainfall events and flooding have increased and these trends are expected to continue. The wettest pentad and total accumulation on the top-10 wettest days of the year are projected to increase by approximately 10% by the middle of this century. While flooding is a complex function of climate, meteorology, soils, water management and land-use, these tendencies are likely to amplify risks associated with erosion, declining water quality and loss of agricultural productivity. 6) The Great Lakes are the world's largest freshwater resource. Climate change will exacerbate a range of risks to the Great Lakes including changes in fish species, increased invasive species, declining beach health, and harmful blooms of algae. Declines in ice cover will continue to lengthen the commercial navigation season, but may be associated with enhancement of shoreline erosion.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFMGC13E..05B
- Keywords:
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- 0468 BIOGEOSCIENCES / Natural hazards;
- 1616 GLOBAL CHANGE / Climate variability;
- 1630 GLOBAL CHANGE / Impacts of global change;
- 1637 GLOBAL CHANGE / Regional climate change