Extreme Weather and Resilience: An Ounce of Prevention

A recent Senate hearing highlighted some of the progress U.S. communities are making, and the major challenges they face, in better coping with costly extreme weather events — including those, such as heat waves and coastal flooding, whose risks are heightened by climate change.

Sen. Tom Carper, chairman of the Homeland Security and Governmental Affairs Committee, noted that the “frequency and intensity of these extreme weather events are costing our country a lot - not just in lives impacted – but in economic costs, as well.” Nearly 130 weather-related events in 2013 caused more than $20 billion in losses in the United States.

Extreme weather is costly, not only to federal, state, and local governments, but also to businesses and individuals.

Much of the Senate testimony echoed key findings in our report, “Weathering the Storm, Building Business Resilience to Climate Change.”  Three key points made at the hearing were:

The State of the Climate

As President Barack Obama prepares to deliver his State of the Union address, we believe it’s a good time to take a look at the state of our climate: the growing impacts of climate change, recent progress in reducing U.S. emissions, and further steps we can take to protect the climate and ourselves.

The consequences of rising emissions are serious. The U.S. average temperature has increased by about 1.5°F since 1895 with 80 percent of this increase occurring since 1980, according to the draft National Climate Assessment. Greenhouse gases could raise temperatures 2° to 4°F in most areas of the United States over the next few decades, bringing significant changes to local climates and ecosystems.

Chilling out on the Polar Vortex

This week’s brief but bitter cold snap over more than half the country prompted intense discussion about the polar vortex ranging from educational to bombastic.

Figure 1: A depiction of the “average” polar vortex on Jan. 6. The winds of the vortex correspond to the narrow “rainbow” areas. The map is an average of the upper atmosphere’s “topography” (specifically, the 500 millibar height) from all the January 6ths between 1980 and 2010.
Figure 2: The polar vortex on Jan. 6, 2014. The ridge (“R”) and trough (“T”) responsible for relatively warm weather in much of the West and bitterly cold weather in the Midwest and East have been labeled.

So let’s be clear: The cold snap this week was unusual but not entirely unprecedented. A few super-cold days don’t disprove global warming, just like a day of rain doesn’t end a drought. At the same time, we don’t yet know whether climate change will change the odds of future outbreaks of bitter cold. Research is still underway, and as of now, we shouldn’t necessarily expect these events to be more or less frequent in future winters. 
Here’s a Q&A to cut through the hype:

  • What is the polar vortex?  The polar vortex describes the air circulating aloft (thousands of feet above the ground) about the North Pole, and its extent is marked by a ribbon of strong winds that is often called the “jet stream.” (We most commonly focus on the North Pole, but a similar circulation is present around the South Pole, too).
    In the map (Figure 1), which is from the point of view of the North Pole, the vortex corresponds to purple and blue colored areas. The band where the colors change from blue/purple to red/yellow indicates the location of the jet stream, or the outer edge of the vortex. Winds are strongest where this color gradient is tightly packed (e.g., over the Pacific Ocean and North Atlantic Ocean). It tends to be quite cold at the surface below the purple areas, and warmer under the red/yellow areas.

It’s important to note that this figure is an average of many winter days. On any given day, we would see a number of deviations from this average pattern.

  • What happened this week? Comparing this week (Figure 2) to the average picture (Figure 1), we can see that the purple area of the vortex has contorted and moved farther south. Along with this pattern, there are substantial “wiggles” in the jet stream. These deviations in the circulation helped bring cold air into the continental United States that normally stays in northern Canada and the Arctic. Meteorologists look for these wiggles, called “ridges” and “troughs” (“R” and “T” on the map)  when putting together a forecast. While the trough brought notable cold to the Midwest and the East, the ridge has kept parts of the West warmer than average and relatively dry (much to the dismay of skiers).

On our own?

Spring not only brings us daffodils and cherry blossoms in Washington, D.C., but also occasionally powerful thunderstorms that can knock out power to thousands of homes and businesses.

I live in one of those northern and western suburbs of DC that tend to lose power fairly frequently.

It used to be that one of the few nice things about losing power was the sound of silence. But those days are gone. Now losing power has a new sound: the whirring of the startup of my neighbors’ backup generators.

We need power not only to keep our food from spoiling and protect us from uncomfortable and even dangerous heat, but also to stay connected. As a nation, we are becoming ever more dependent on electronic devices. We cannot survive without our cell phones and computers, let alone our refrigerators and air conditioners. At the same time, climate change threatens the reliability of the grid through more intense heat waves and potentially more powerful storms.

While it’s easy to say we should work to prevent disruption in electricity, how much should we invest to bolster the resilience of the grid? And who should pay?

How climate change amplified Sandy’s impacts

As Hurricane Sandy moves out of the region, people in affected areas are beginning to take stock of the damage. Flooding in parts of New Jersey and New York from the storm surge hit record levels. The 13.8-foot surge measured at Battery Park in Lower Manhattan surpassed the all-time record of 11.2 feet set in 1821, flooding the New York subway system and two major commuter tunnels.  Along the Eastern Seaboard, an estimated 7.5 million people lost power. Farther inland, blizzard conditions dropped as much as 2 feet of snow as Sandy crashed into arctic air over the Midwest. While early estimates indicate direct damages from the hurricane may be as much as $20 billion, the total economic losses, including losses in consumer and business spending, could be more than twice that amount.

A number of climate change-related factors may well have intensified the storm's impact: higher ocean temperatures, higher sea levels, and an atmospheric traffic jam that may be related to Arctic melting.  Hurricane Sandy is also a clear reminder of how vulnerable our homes and infrastructure already are to extreme weather — and this risk is growing.