What Would Happen if All the Ice on Earth Melted?

Sea level rise is a significant consequence of global warming.  It poses serious problems for coastal communities around the world.

According to the IPCC, average global sea level has risen 7.5 inches since 1901.  While that may not seem like a lot, every inch counts when a storm surge rushes inland – as we recently saw with Sandy and Haiyan.  As our atmosphere continues to warm, land-based ice, like glaciers and ice sheets, are expected to continue to melt and push sea levels even higher.

Exploring this idea, National Geographic recently published a series of artist renderings that depict what the world map would look like if all the ice on the planet – approximately five million cubic miles – melted.  Producing a sea level rise of 216 feet above current levels, entire cities would be submerged and the familiar outline of the continents would be irreparably altered.

While this dire situation is not expected to happen anytime soon, these images offer an incredible visualization of what could ultimately happen to our coastlines if the atmosphere and oceans continue to warm unabated.

Extreme Weather Impacts the National Flood Insurance Program

Hurricanes and floods are nothing new in the United States.  In the last decade, however, this country has seen a significant increase in these types of extreme weather events.  In response to the financial strain they have put on the National Flood Insurance Program (NFIP), Congress passed the Biggert-Waters Insurance Reform Act of 2012 (BW-12).

The NFIP, operated by the Federal Emergency Management Agency (FEMA), offers insurance for individual businesses and homeowners in flood prone areas. Congress created this program in 1968 in response to the financial chaos caused by Hurricane Betsy in 1965. This storm, which devastated the Gulf Coast, was the first billion-dollar natural disaster in U.S. history.

To calculate flood risk and the corresponding insurance rates for properties, the NFIP uses special maps that indicate flood zones.  Many of these flood insurance rate maps, however, have not been updated in decades and do not reflect the current flood risk associated with our changing environment.  As a result, many policyholders have been paying below market rates.

The Biggert-Waters Insurance Reform Act re-authorizes the NFIP for five years, but requires a number of changes.  These include, the gradual phasing out of subsidized policies and moving the program toward risk-based rates as new flood insurance rate maps become available.  Subsidized policyholders will see a rate increase of 25% per year until their premiums reflect the actual risk of their location. Non-primary residences, non-residential properties, and repetitive loss properties will be among the first to see these changes.

BW-12 was signed into law a few months before Super-storm Sandy devastated coastal communities throughout the northeast.  Many people whose homes were damaged or destroyed by Sandy’s record storm surge are now beginning to feel the effects of this new policy.

Sandy Highlights the Dangers of Rising Sea Levels

Six months ago today, Super-storm Sandy devastated a large section of the northeastern United States.  The flooding caused by its record storm surge was a heart-wrenching example of the dangers posed by rising sea levels.

Storm surge is the rise in sea height that occurs during an intense storm like a hurricane or nor’easter. Its baseline is local sea level. So, as sea levels rise, storm surges are able to reach further inland.  This is a serious problem for coastal communities around the world.

According to climate scientists, the average global sea level has risen about eight inches since 1880.  This may not sound like a lot, but it is a significant amount when you consider it is spread out across all of the world’s oceans.  That said, sea levels are not rising evenly across the planet.  Recent studies have found that certain areas, such as the East Coast of the US, are experiencing faster rates of sea level rise than others.  New York Harbor, for example, has seen its water level increase by more than a foot in the past century.

Sea level rise has two main drivers. They are thermal expansion – a process in which water expands as it warms – and the melting of massive amounts of land based ice, such as glaciers and ice sheets.  Both are the result of rising global temperatures.

In the future, sea levels are expected to continue rising as our atmosphere warms. Estimates of how much vary from four inches to two feet above current levels by 2050. This wide range reflects uncertainty in the amount of future greenhouse gas emissions, subsequent warming, and rate of ice melt.  What is certain, however, is that the frequency and magnitude of storm surge flooding will increase as sea levels rise.