Weather Intelligence

Changing Climate: What Does It Mean? Part Three: Changing Weather Volatility

In our previous post we talked about the changes in weather patterns our Schneider Electric meteorologists are observing in relation to climate change. To wrap up our series, we’ll look at what the impacts are of increased climate volatility.

While there are no absolute answers, recent trends do suggest an increase in extreme events. These events aren’t uniformly distributed across the globe, or evenly spaced in time – but rather are focused on regional areas with increasing frequency.

Increased flooding

The 2007 Intergovernmental Panel on Climate Change (IPCC) report shows increased frequency of intense rain events over the last 50 years. In areas with more frequent excessive rainfall and increased run-off from land use changes, more significant flash flooding events could occur.

Increased drought

The National Center for Atmospheric Research has found that the percentage of Earth’s surface suffering drought has more than doubled since the 1970s. In Africa alone, the IPCC projects that between 75 and 250 million people will be exposed to increased water stress due to climate change. Specific areas, like the western United States, sub-Saharan Africa and central Asia, have experienced cyclic drought in recent years.

More hurricanes and coastal storms

As the oceans warm, scientists predict that the number of hurricanes and tropical storms will increase. Low lying cities are at particular risk for associated storm surges, due to higher sea levels from warmer ocean waters and the increase of glacial meltwater entering the ocean system.

Increase in extreme warm/cold periods

The tendency for weather patterns to stall more frequently may lead to greater instances of extreme warm or cold periods, lasting weeks or even months. The disruption of the polar jet stream that normally causes progressive patterns of winds has produced extreme winter cold in Europe, Asia and Alaska. While you’d think that a generally warming climate would lead to more hot events, the increase variability of the system can also create more extreme cold.

Wildfires

Hotter and drier conditions create a tinderbox ideal for wildfires. In areas of persistent drought, like the southwestern United States or southeastern Australia, wildfires could have a devastating impact. Wildfires have increased in recent decades around the world.

Changing jet stream patterns

While it’s not as visible as a hurricane or a tornado, the changes in the jet stream could be setting us up for greater problems in the future. Some recent trends show a weakening of the jet stream in the more northern latitudes, but with increasing winds occurring from Europe to the Central Atlantic, they could cause more turbulent patterns in the North Atlantic Ocean. Air travel may be impacted in order to avoid more turbulent areas.

Black Swan events

The wild card: “Black Swan” events, the extreme outliers.  A “Black Swan” event happens when least expected, with a notable example being Hurricane Sandy making an unforeseen left turn into the Mid-Atlantic region, causing massive amounts of damage. New Mexico experienced their own “Black Swan” with a severe cold snap causing widespread power outages in February 2011.

Even as weather observations, modeling and forecasting have improved, extreme and unexpected events remain on the edges or outside of normal bounds and are difficult to predict. There needs to be greater awareness, imagination and acknowledgement for these types of extreme outlier events to occur. Even though they may be counter to reasonable expectations, they should not be discounted.

Plan for the worst

While climatologists are still trying to sort out the human and natural influences that cause climate change, it is clear that more disruptive weather events have been occurring and will likely continue to happen at an increased frequency over the next few decades. From a business and planning perspective, it’s essential to be aware that the worst has happened and will happen again – and increase the awareness and planning for both anticipated and unanticipated extreme weather events.

For a free download of our new white paper, “Changing Climate:  What Does It Mean?”, click here.

 


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