Colorado floods show challenge of global weirding

Heavy Rain Fuels Major Colorado Floods
© Marc Piscotty/Getty Images

Last week, Colorado received "biblical" amounts of rainfall and the effects have been devastating, with six people confirmed dead and up to 1,253 people still reported missing as of this morning.

The Denver Post reports:

Emergency management officials said 17,494 homes were damaged, 1,502 homes were destroyed and 11,700 people were ordered evacuated.

As of Sunday, rescuers had evacuated more than 2,100 people and more than 500 pets, most by helicopter.

Making matters even worse, weather forecasts show chances of thunderstorms again for today and tomorrow in already flooded areas.

Ryan Koronowski at Think Progress has a good chart on the unprecedented amount of rain:

This is daily precipitation data from a weather station in Boulder over the last 120 years. Each red cross is the amount that fell in one 24-hour period, and each point is plotted against the “return period,” or how often on average that amount can be expected every 1, 2, 5, 10, 100, 1,000, or 10,000 years. The vast majority of readings fall below 10 years, or about 80 millimeters in one day.

After that it’s easy to pick out individual days. So the big outlier on the graph in the upper right is one day where about 120 millimeters (4.8 inches) of rain fell on this station, expected to happen once every 100 years.

On Wednesday and Thursday in just one 15-hour period, 183 millimeters fell on Boulder, which is 7.21 inches — literally off the chart. The previous wettest September day was in 1909, with just over 3 inches.

What’s happening in Colorado is that unprecedented.

While it is true that any one particular storm or weather event cannot be attributed to climate change alone, unusual rain such as this is precisely the type of "global weirding" that climate scientists have predicted would occur as the climate warmed.

Relatedly, while Colorado is receiving epic, record-setting amounts of rain, it's neighbor to the east, Kansas, is still suffering from a drought and is running out of water, in some parts of the state.

These are the sorts of weird pattern changes that climate change can lead to. Even areas where massive flooding occurs can still find themselves too dry throughout a season, because during the unusually heavy rainfall, the ground becomes over-saturated and rainwater runs downstream. Under normal circumstances, rain may have been spread out in a more normal distribution, so vegetation and aquifers would be better able to absorb and store that water over the course of a season.

This disaster in Colorado is far from over, but early reports are suggesting damage could exceed $1 billion. How many more costly events like this will it take before we finally get serious about spending the billions or trillions needed to prevent future risk by addressing climate change, rebuilding our infrastructure and reducing our fossil fuel emissions rather than spending billions in disaster recovery?

The Denver Post has a list of ways you can help.

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