Climate and Weather

Background

Join Dr. Jennifer Francis, a world-renowned climate researcher at Rutgers University and Bob Lindmeier, the chief meteorologist at ABC affiliate WKOW in Madison, Wisconsin to learn more about how this complexity can be effectively communicated to the general public. Rick Knight, CCL's IL State Coordinator, moderates. 

What We Know

Greenhouse gases block the radiant cooling of the earth, causing the trapped heat energy to build up in the atmosphere and the oceans. Since weather is driven by energy, with more energy building up in the system, normal weather cycles become more extreme, fueled by more heat and moisture. [1]

That leads to more extreme weather. While the precise timing and location cannot be predicted far in advance, hurricanes, droughts, heat waves, massive downpours, and even extreme snowfall in some areas are becoming more frequent and more severe. Over time, the U.S. has seen increases in prolonged periods of excessively high temperatures, heavy downpours, and in some regions, severe floods and droughts.[2] For example, approximately twice as many extreme U.S. snow storms occurred in the latter half of the 20th century than in the first. [3] 

Adding to weather disruption is the loss of Arctic sea ice and ice sheets, which may be changing the large-scale patterns of jet streams that govern weather all over the globe. Many scientists think that the arctic warming can affect the polar front jet stream — the ribbon of strong winds found high in the atmosphere that controls a good portion of winter weather at midlatitudes. [4,5] Global warming of the polar regions causes ice melt, adding fresh water to the salty ocean. The fresh water may have an impact on important ocean currents, such as the gulf stream, which warms the U.S. east coast and western Europe. [6]

The Costs of Extreme Weather

Climate-induced supercharging of weather is not just an academic topic, but one that impacts our economy. In 2017, extreme weather events cost the U.S. a jaw-dropping $306 billion. And since 1980, the U.S. has sustained 219 weather and climate disasters where the overall damage costs reached or exceeded $1 billion (including adjustments based on the Consumer Price Index, as of December 2017). The cumulative costs for these 219 events exceed $1.5 trillion. [7] Climate change is known to contribute to that cost. [8]  For example, heavy rainfall events and their ensuing flood risks are increasing because warmer temperatures are "loading" the atmosphere with more water vapor. Over time, this increases the potential for extreme rainfall events. [9] The size of that contribution is still far from being pinned down, it’s safe to say it’s not zero, judging from discussions inside the insurance industry. A recent report argued that from payouts after a hurricane, flood or other disaster to lawsuits that could wrap them up in costly litigation, insurers and reinsurers are severely exposed to the perils of climate change.[10]

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  • Note:  Dr Francis’ slides aren't included, only Lindmeier’s are linked for download
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