Sunday, July 18, 2021

Rain, Drought and Climate Change

Wildfires are burning in California and the Pacific Northwest.  Last week Europe was inundated with rain, and it is believed that hundreds may have been killed in the flooding in Germany alone. Though each extreme event needs to be studied by scientists before it can be determined how much is attributed to weather variability or climate change, Scientists tell us the impacts of a changing climate are arriving. Heat waves, droughts, increased storm intensity and intense cold snaps are all predicted to increase.

The industrial activities that our modern civilization depends upon have raised atmospheric carbon dioxide levels from 280 parts per million to the current 417 parts per million in the last 150 years and will continue to rise. Scientists believe the human-produced greenhouse gases: carbon dioxide, methane and nitrous oxide have caused much of the 1-degree Celsius increase in Earth's temperatures since 1880. Unfortunately, scientists also believe that we have passed the tipping point which was 400 parts per million of CO2 equivalents in the atmosphere.

The IPCC (Intergovernmental Panel on Climate Change created by the World Meteorological Organization) considers some additional warming of the planet to be irreversible. According to the IPPC, “Many aspects of climate change and associated impacts will continue for centuries, even if anthropogenic emissions of greenhouse gases are stopped. The risks of abrupt or irreversible changes increase as the magnitude of the warming increases.” The expected impacts are continued warming of the planet, rainfall pattern changes and significant rising of sea level.

According to NASA: “Current climate models indicate thatrising temperatures will intensify the Earth’s water cycle, increasingevaporation. Increased evaporation will result in more frequent and intensestorms; but will also contribute to drying over some land areas. As a result,storm-affected areas are likely to experience increases in precipitation and increasedrisk of flooding, while areas located far away from storm tracks are likely toexperience less precipitation and increased risk of drought.

There is not going to be less precipitation, warmer air can hold more moisture and rainstorms on a global scale may increase. There will be less snow and rain patterns and location will change. We must prepare for that. The flooding in Europe was caused by a storm that stalled out for hours as seven inches of rain fell. This was a fraction of the 40 inches of rain some areas of Texas received when Hurricane Harvey stalled out for four days but may be an indication of future events.  It is postulated that the warming in the Artic is weakening the jet stream that would result in storms moving more slowly. A study from the Earth Institute ofColumbia University indicates that weather events could become more extreme andwould linger longer. Longer heat waves, cold snaps and slower moving storms.

We are past the point where we can try to stop or reverse climate change and hope the climate will return to what it had been. It is a couple of decades too late for that. We now need to prepare. Much of the historic development in cities makes flooding from intense storms worse. Local topography, the amount of impervious cover, stormwater infrastructure all can impact the amount of flooding which can disrupt transportation, water and sewer and other utilities. This was demonstrated in Europe this past week; however, while the Germans were being inundated, the Dutch were not.

About 15 years ago the Dutch Government began the development of the “Room for the River Program.” The main strategy was to reduce flooding (always a problem for the Dutch) and manage higher water levels in rivers by lowering the levels of flood plains, creating water buffers, relocating levees, increasing the depth of side channels, and the construction of flood bypasses. This program involved over 30 coordinated projects that were completed at the end of 2018. While there was a breach in one dike last week that caused some flooding briefly until it was repaired, the program prevented major flooding.

 We need to emulatethe Dutch and protect our cities and communities from climate change. We cannot stop it, that ship sailed. If we are to survive as a first world nation and protect our most vulnerable, we must face the facts. We cannot throw away our financial flexibility on feel good programs and aggressive carbon reduction schemes that are too late to make a difference.  We need to plan and build for the future we are going to have. Realistic preparation for the future is what we need to do. 

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