Environment

Climate change: It’s the T-rex chasing the jeep in Jurassic Park and the climate scientist is Jeff Goldblum yelling “must go faster.” It’s omnipresent and ineffable, it’s everywhere and touches everything. It’s a problem so complex that it’s easy to distract ourselves with the efficacy of plastic straw bans and recycling.

We can do more. We should do more. But where do we start? And what agency do we have as individuals compared with industrial behemoths like big oil, Amazon, Walmart and Starbucks?

Well there’s one simple trick (working the Buzzfeed angle here). It, by itself, won’t reverse or even slow climate change much on its own. But it’s a start. A good start. An easy start.

This simple solution has the ability to limit local impacts of warming, flooding and air pollution all while combating the global scourge of rising CO2 levels. 

And it’s viable in Kentucky — but before we get to that, it’s important to understand how climate change is already affecting the state, and what we can expect in the future. 

Kentucky’s Climate In Context

To start with the good news, Kentucky State Climatologist Stuart Foster agrees that, in the context of climate change, the Commonwealth seems like a good place to buy a house. Or at least better than some other places (I’m looking at you California and Florida).

Foster says Kentucky’s hottest period of late occurred during the first half of the 20th century, though we’re catching up.

The state has seen about a 1.41 degree rise in average temperatures over the last 30 years, according to data analyzed by the Associated Press. Another piece of the puzzle that stands out is an increase in average overnight low temperatures.

The state has also experienced a weirdly wet decade. The last time Kentucky saw this much rain was back in the 1800’s, Foster said. Last year was the wettest on record in the state. Foster also pointed to extreme rains in 2010, which were followed by a drought. Then in spring 2011, flooding along the Ohio River gave way to a drought the following year in the western part of the state.

That’s the kind of thing you expect to see from climate change. It’s also pretty good representation of the kind of extreme events that are more likely to take place in the future.

Kentucky will see warming temperatures causing more extreme weather events. There will be more heat waves and more droughts. Rain may become less likely in the summer months, but overall it is expected to get wetter, according to the 2017 Ohio River Basin climate report by the U.S. Army Corps of Engineers. And when storms come, they will be more intense, capable of creating historic river flooding and flash flooding.  

Ed Hawkins

Kentucky’s annual average temperatures from 1895 to 2018 created by Climate Scientist Ed Hawkins.

While it can seem counter-intuitive, heavy storms and precipitation are consistent with a warming climate. That’s because warmer air can hold more moisture, making for bigger storms.

Baby It’s Warm Outside

How bad will it get? Well, the climate is changing faster than at any point in modern civilization and the responsibility rests squarely on the shoulders of mankind. 

Consider that climate scientist James Hansen delivered his seminal report on the impacts of global warming to senators in 1988. Since then, mankind has released about half of all of the carbon in the atmosphere, according to the Oak Ridge National Laboratory study “Global, Regional, and National Fossil Fuel CO2 Emissions.”

Every degree of warming will bring its own challenges, both known and unknown, with possible tipping points, die offs and feedback loops.

Over the coming decades, the southern climate will creep steadily north, making Kentucky’s climate look a whole lot more like Tennessee. Trees like the sugar maple, with its brilliant red-orange fall leaves, will recede from the landscape along with other flora and fauna that prefer cooler climates.

In the city, summers will become longer and the hot days will become sweltering.

That sounds unpleasant, but it’s far worse than that. There are cascading impacts. Increased temperatures exacerbate air pollution. Heat and solar radiation will lead to more ground-level ozone and Louisville is already exceeding EPA standards for that pollutant. Heatwaves, droughts and hot days will also put more dust and fine particulate matter in the air, increasing the risk of asthma, heart and lung disease.

Direct heat itself increases mortality rates across the country. It also lowers productivity — something anyone who works outside understands — and there is evidence that warming increases rates of violence.  

In Kentucky, only about six days per year are classified as having a heat index above 100 degrees right now, but that could reach 45 days by 2050 without global carbon reductions — and 76 days by 2100.

Worse yet, Kentuckians may have to endure about 10 days of temperatures that could exceed 127 degrees by the end of the century.

A Tall Drink Of Water

For the next two decades Louisville can expect to see more frequent flooding like the first half of the 20th century. That frequency increases the risk the city could repeat the Great Flood of 1937 when waters from the Ohio River inundated more than two-thirds of the city.

Today, a similarly catastrophic river flood could affect more than 200,000 residents and as much as $34 billion in property, according to the Army Corps of Engineers.

Louisville’s 29-mile flood protection system is among the largest in the country and is also deteriorating (the oldest sections were built between 1947 and 1956 and much of the technology is still based on designed from that period).

Metropolitan Sewer District

This picture is from a Metropolitan Sewer District tool that models catastrophic flooding in Louisville. This photo depicts the same levels of water that inundated the city in 1937.

Urban flooding generally happens for one of two reasons: Either long-term rains saturate the ground and raise river levels, or heavy storms inundate the city, causing flash flooding.

Between 2040 and the end of the century, the extra precipitation across the region is forecast to cause Ohio River maximum stream flows to rise as much as 35 percent. 

Other Kentucky cities are at an even higher risk of river flooding, as many of the state’s smaller rivers and streams will also have flooding impacts, but without the benefit of Army Corps’ locks and dams to help control the flow.

Flash flooding, in particular, will get worse, especially in already flood-prone areas. The more concrete and asphalt a city has, the more water runs off. Last year, Louisville hung signs and markers in more than 30 areas warning residents not to enter flooded. But the signs came too late: Louisville cab driver Abdinasir Siyat drowned in a flooded underpass in September 2018.

All of this flooding will test the limits of the city’s aging sewer infrastructure, which collects stormwater. The result will be more sewer cave-ins, more collapses, and more sewage ending up in urban streams and the Ohio River.

Gimme Shelter (In Kentucky)

Around the state, there’s a big question mark around crop yields. Weather extremes are clearly distressing to state farmers, but the effects of warming are complex. On one hand, as a general rule, cereal crop yields decline 10 percent for every degree of warming, according to a study by David S. Battisti.

On the other, longer summers could potentially benefit farmers and help crop yields. However, the summers will also likely help pests such as mosquitoes and ticks, which will have more time to breed.

The severity of these climate impacts depends on temperature, and temperature depends on the amount of greenhouse gases humans put into the atmosphere. That’s where a lot of uncertainty lies and that’s why the world’s leading body on climate science, the U.N.’s Intergovernmental Panel on Climate Change, presents a range of scenarios.

Ryan Van Velzer | wfpl.org

Right now, the planet is on track to be 2.7 degrees Fahrenheit warmer than pre-industrial levels by about 2040. Just 3.6 degrees of warming presents an urgent and potentially irreversible threat to humankind and the planet.

It’s the difference between losing 70 to 90 percent of the world’s coral reefs and losing virtually all of the world’s reefs. It’s the difference between the likelihood of losing all of the Arctic Ocean’s sea ice once per century versus losing it once per decade.

Sea levels will rise. The cascading impacts will force people from coastlines across the world. In the U.S. alone, nearly 2.5 million residential properties valued at more than $1 trillion are at risk of chronic flooding, according to the Union of Concerned Scientists.

That will certainly indirectly affect Kentucky as people flee the coasts. As will the economic devastation climate change wreaks on the planet. Each degree Celsius of warming, could reduce growth by more than one percentage point (the U.S. economy saw 2.9 percent growth in 2018), according to “Estimating Economic Damage from Climate Change in the U.S.”

Now Back To That ‘One Neat Trick’

Despite all this, Kentucky is geographically situated to receive fewer climate impacts than many other places in the United States. Stuart Foster, the state climatologist, doesn’t expect Kentucky will see the wildfires that have ravaged California, nor the desertification that affects other southern parts of the U.S.

Kentucky has abundance: freshwater, verdant forest and rich soil. How can we leverage our abundance in a way that provides for the future?

That brings me back to that one neat trick: something we can do that will not only help to reverse global warming, but limit its local and regional impacts. It’s nearly ridiculous in its simplicity, but the benefits simply cannot be overstated: Plant more trees.

This week, WFPL News will explore Kentucky’s forests, urban and rural, and the benefits they provide. 

This story is part of Covering Climate Now, a global collaboration of more than 250 news outlets to strengthen coverage of the climate story.

Ryan Van Velzer is WFPL's Energy and Environment Reporter.