Dec 212014
 

U.S. Cities Already Flooding

We already posted an article about U.S. cities that are predicted to go underwater because of climate change but not about cities that are already at the tipping point of experiencing at least nuisance-level flooding at an accelerated rate. Accelerated flooding is already mostly noted along the Gulf Coast and East Cost of the United States. These means that the rate of flooding is not just increasing but that it is also accelerating. Particularly noteworthy is what is known as sunny day flooding, times when streets flood and there is no big storm to account for it, just high tide.

The tipping point has been described as nuisance flooding at least 30 days out of the year. The main point from the chart displayed below is that Wilmington, NC, Washington, DC, and Annapolis, MD. are already past the tipping point. At least a half dozen more major cities are expected to reach it by 2020 and dozens more in the next few decades after that.

Defining Nuisance Flooding and Tipping Points

Cities already at the tipping point:  Image: Earth's Future/Sweet and Park 2014

Cities already at the tipping point:
Image: Earth’s Future/Sweet and Park 2014

Nuisance flooding is defined as sea levels of about one to two feet over typical high tides, and these floods tend to impact city streets of areas that are no more than a couple of feet over sea level. The problem is that this used to be rare or caused by large weather events, and it is not becoming common. In other words, the ecology of coastal areas in the United States and all around the globe has already reached a tipping point or a new equilibrium, but there is no way to provide assurance that the situation won’t get worse. Because of accelerated rates of minor flooding, it would probably be prudent to expect that it will get worse.

Major U.S. Cities Studied for Nuisance Flooding

These conclusions were drawn from measurements taken over 100 years. The reason that Miami, currently experiencing plenty of sunny day flooding, was not included is because the measurement point was moved after Hurricane Andrew, so 100 years of consistent data is not available.

These are the major cities highlighted in the study:

  • Boston, MA
  • Providence, RI
  • New London, CT
  • New York City, NY
  • Atlantic City, NJ
  • Washington, DC
  • Philadelphia, PA
  • Baltimore, MA
  • Charleston, SC
  • Key West, FL
  • Galveston, TX
  • Port Isabel, TX
  • La Jolla, CA
  • San Francisco, CA
  • Seattle, WA

Rates are different at different spots along U.S. coastlines. The scientists remind us that the ocean is not flat and level like a bathtub. Currently, in the U.S., The Gulf of Mexico and the Atlantic cities are experiencing worse rates of accelerated flooding than is getting experienced along the Pacific.

Conclusions About Accelerated Flooding in U.S. Coastal Cities

This is the conclusion of the study cited in the first source:

Impacts from recurrent coastal flooding include overwhelmed storm water drainage capacity at high tide, frequent road closures, and general deterioration and corrosion of infrastructure not designed to withstand frequent inundation or saltwater exposure. As sea levels continue to rise and with an anticipated acceleration in the rate of rise from ocean warming and land ice melt, concern exists as to when more substantive impacts from tidal flooding of greater frequency and duration will regularly occur. Information quantifying these occurrences and the associated frequency-based tipping points is critical for assisting decision makers who are responsible for the necessary mitigation and adaptation efforts in response to sea level rise.

Sources:

From the extreme to the mean: Acceleration and tipping points of coastal inundation from sea level rise :  http://onlinelibrary.wiley.com/enhanced/doi/10.1002/2014EF000272/

Dec 152014
 
Carbon Dioxide Graph

Yes, sorry, climate change is for real. Climate change isn’t even new, and it is obvious to anybody who studies the planet that Earth’s climate has never been static. It may only seem that way to beings with short life spans in comparison to geologic time.

What’s novel this time is that we are experiencing really fast climate change over the entire globe that is obviously influenced by man-made activities.

Here’s what we do know about real climate change:

  • Right wing rags don’t matter.
  • Politics don’t matter.
  • Science Matters!
Scientific evidence for warming of the climate system is unequivocal.
– Intergovernmental Panel on Climate Change

How Do We Know Climate Change is Real and Manmade?

The CO2 Spike

Carbon Dioxide Graph

Carbon Dioxide Graph – WikiMedia Commons

The first climate change evidence in this exhibit is the carbon dioxide graph. From NASA’s Climate Change pages (NASA does science really well), we find that the levels of CO2, a greenhouse gas, is more concentrated in our atmosphere than it has been for 650,00 years. The thing is that carbon dioxide levels crossed the red line in 1950 and have continued to spike.

Greenhouse gasses, like CO2 and methane, trap heat and get their name from this impact. Incidentally, there is more CO2 than methane in the atmosphere, but methane takes longer to dissipate, so that’s not a good thing either.

Humans are largely responsible for global climate change. – The U.S. EPA

Real Climate Change Evidence

OK, so now you know why climate change is occurring rapidly, so what’s happening? Earth’s climate has warmed about 1.4 degrees F over the last century. A degree or two here and there may not seem like much, but not all areas of the globe experience change at the same rate, so this average accounts for lower and higher degrees of climate change.

But here’s the real climate change problem that we need to wake up to. The planet is expected to warm another 2 to 11 degrees F in the next century. Also, the only impact is not just warmer days but is the impact on global weather problems. Also, because warming temperatures melt ice sheets and change ocean and atmospheric patterns, some places will get quite a bit colder … for awhile.

Here’s the list of what’s already happening to indicate that the earth is rapidly warming:

  • Sea levels rise: In the last 100 years, global sea levels have increased an average of 6.7 inches. In the last 10 years, the rate has nearly doubled over the average of the last century.
  • Air temperatures rise: Over that same last 100 years, global average temperatures have increased. Most of this has happened since 1970, and the top 20 years for rising temperatures have been since 1981.
  • Ocean temperatures rise: Part of the reason that the air temperature has not increased more is because the oceans have soaked up a lot of the increased heat.  On this water planet, ocean climate change is also climate change for real. Also, oceans have become 30 percent more acid since the dawn of the Industrial Revolution.
  • Declining sea ice and ice sheets: Both the Greenland and Antarctic ice sheets have decreased, mostly since 2002. Arctic sea ice has also declined both in area and thickness. Glaciers are melting all over the world. This includes Alaska, the Himalayas, the Alps, the Rocky Mountains, and the Andes. Also, snow cover has decreased in the last half a century, and snow is melting earlier in the spring than it used to.
  • Extreme weather: At the same time, in the United States, the number of record high temperatures has increased while the number of record lows has decreased since 1950. Also, the number of extreme weather events has been on the rise.

Climate Change is the Real Future

There is still some disagreement that humans are creating climate change, but between scientists, the consensus is clear as all that ice the planet is losing. Any student of Earth science knows that climate change happens. But there is no disagreement among scientists that the climate is rapidly changing, and the factors that are mostly responsible for that change came from human activities. As these activities increased, so did the level of greenhouse gasses and the rising mercury.

People did it, but we may not be able to totally reverse it. Even if people stopped emitting greenhouse gassed and cutting down forests tomorrow, it could take 10 centuries for the world to revert back to the way it was before industry. We need to reduce it as much as we can. However, climate change is real, and we may have to adapt.

Learn more:

Global Climate Change: Vital Signs of the Planet (NASA): http://climate.nasa.gov/evidence/

Climate Change Basics (U.S. Environmental Protection Agency): http://www.epa.gov/climatechange/basics/

 

 

Dec 102014
 
U.S. cities under water

According to a PBS article, Will Your City be Under Water, previous estimates of just how many U.S. cities would flood were too conservative because scientists only considered the relation of the land to sea level but not to high tide. For example, about 5 million people live in about a quarter of a million residences that are less than four feet over high tide. That’s within a century, but sea levels could rise by 19 inches by 2050, and that’s well within many of our reader’s lifetime.

The Surging Seas Interactive Map

This widget comes from ClimateCentral.org, and it allows you to adjust for different predicted levels of rising waters and high tides to see current predictions. You can choose to view maps, see quick summaries, and spend time viewing a very detailed analysis. In some cases, this drills down to the neighborhood level or threatened cities.

If you’re interested in seeing if your own city is threatened by rising tides, you can also visit ClimateCentral.org for an interactive map and much more detailed analysis. The estimates of rising sea levels and tides in the next century is from two to seven feet. The map allows you to adjust for different increases to see how it impacts different cities and regions under a variety of sea level and high tide rise scenarios .

Note: The map does not account for future preventative members like the erection of sea walls.

States with the greatest populations in harm’s way of a sea level rise:

  • Florida
  • Louisiana
  • California
  • New York
  • New Jersey

Florida is the state with the greatest population at risk of losing their homes.There have already been many dire predictions that large parts of the Miami Metro area are doomed. So far, attempts to build sea walls and increase the elevation of buildings have not worked. The problem is that the water is beginning to saturate the limestone that provides the land for the tip of Florida, and the city is actually sinking as the sea rises.

All of  these states also have very dense populations near the sea, so it does not mean they are the only states with a lot of land area to lose. Any state with a coastline by the Atlantic, Pacific, or Gulf of Mexico faces the same threats. Of course this includes Texas and other Gulf Coast state, the Pacific coast, and the Atlantic coast.

Most of these percentages are calculated by the number of residents, and they are not calculated by the square miles of land lost. Of course, the loss of many square miles of land could mean the loss of agriculture, ports, industry, and much more.

Will Sea Level Rise Predictions Come True?

Even the folks at Climate Central caution against taking predictions for any one area as something engraved in stone. However, they do say that when spread over all areas, these predictions are likely to average out as close to correct. For example, they may have overestimated the threat to one city, or not accounted for future preventative measures, but it is likely they were too conservative in other areas. For comparison, this is similar to estimating an athlete’s performance over all games and not just one.

Past Sea Level Increases

According to the Climate Change organization, global temperature changes have increased average sea levels by about 8 inches since the 1880’s, but the rise is now accelerating. Of course, various weather patterns means that the rise is slow some years and catastrophic in others. In other words, the loss of dry land doesn’t just come in a steady line on a graph but in a more jagged one.

Sources:

http://www.pbs.org/newshour/rundown/will-you-be-underwater-theres-a-map-for-that/

http://sealevel.climatecentral.org/