Study: Pennsylvania flood risk rises as climate changes

  • Rachel McDevitt

Most communities in Pennsylvania will likely face higher flood risk by the turn of the century due to climate change, according to a Penn State study.

The state’s latest climate impact assessment expects Pennsylvania to face more extreme rainfall and flooding by 2050 due to climate change.

But the risk of flooding a building or area – and the need for insurance – is determined by looking at past events.

The Penn State article published in the Journal of Hydrometeorology combines historical information on flooding with climate models to estimate future risks.

Climate change and Pennsylvania

There is overwhelming scientific evidence that human activity is warming the Earth at an unprecedented rate. It is already responsible for extreme weather conditions, rising sea levels and more severe droughts around the world. Pennsylvania is on track for more intense heat waves and more severe storms in the years to come, according to the Department of Environmental Protection.

Scientists stress that fast action is crucial to avoid the worst effects. Pennsylvania’s most recent climate action plan calls for an 80% reduction in greenhouse gas emissions by 2050, from 2005 levels.

It will require tough choices on the part of the nation’s fourth-largest carbon emitter: Pennsylvania must find a way to cut emissions while planning for the future of the people and communities that depend on the fossil fuel industry.

The team found that most cities and boroughs in the state are expected to face higher flood risk by 2099. They found that the risk of severe flooding is relatively higher in smaller ones. cities and boroughs than in the largest cities in the state.

Alfonso Mejia, associate professor of civil and environmental engineering and one of the authors of the article, said they initially believed the risk would increase the most in places that are not currently inundated. But it appears the risk is increasing statewide, and flood-prone areas currently remain the most flood-prone in the future.

“The places that… today have the highest flood risk, those same places seem to be the most at risk 50 or 100 years from now,” Mejia said.

For the study, researchers looked at flooding in terms of risk, which refers to the size and likelihood of a flood, and exposure, which takes into account the number of people that would be affected and the cost. damage.

The top three cities with the highest predicted flood risk were Lock Haven, Williamsport and Sunbury, all located along the West Branch Susquehanna River. The study notes that data from the National Oceanic and Atmospheric Administration shows that these cities have all experienced a substantial number of flooding in the past.

The study found that Warren, Bradford, Wilkes Barre, Johnstown, York and Connellsville also face some of the highest risks, with more than 50% flood and exposure risks predicted.

Mejia said the work shows the importance of planning and investing in flood mitigation and adaptation measures now.

“Today’s investments in these high-risk areas will pay off in the future,” Mejia said.

David Dzombak, head of the civil and environmental engineering department at Carnegie Mellon University, was not involved in the study. He said it sounded like work published by the First Street Foundation, which developed a tool to show future climate risks for a given property.

Dzombak said the Penn State document provides useful information for questions communities should be asking.

“Over time, communities, perhaps with guidance and support from the state, may try to move important people and goods out of the most vulnerable places,” Dzombak said.

He added that it was time, as the climate changes, to start working on adaptation measures. He said preparing now would be much cheaper and less disruptive than waiting for disaster to happen and then cleaning up.

The study reveals some uncertainties. The global climate models used in the study cannot take into account all the factors that may influence future flooding.

The study did not take into account existing infrastructure such as dikes that could prevent extreme flood damage. Mejia said they would like to consider this in the future.

He added that the model should be updated as the effects of climate change manifest.