The author of a landmark study on Louisville’s urban heat island is responding to criticism from the city’s chamber of commerce.

In eight pages of comments on the analysis of the city’s urban heat island, Greater Louisville Inc. slammed the study’s methodology and said it didn’t provide enough evidence to justify any new regulations. The comments were first reported Monday by The Courier-Journal.

The urban heat island study was written by Brian Stone of Georgia Tech and released in April. He was commissioned by the city to study the heat island, which has been characterized as one of the fastest-growing in the nation.

The term “heat island” refers to a difference in temperatures between a city’s urban core and surrounding countryside.

Stone’s study lays out specific neighborhood-level solutions for cooling parts of Louisville. It quantifies the number of trees, cool roofs and cool parking lots the data analysis deems necessary to slow the city’s warming and — in the process — reduce the number of possible deaths and health problems due to extreme heat.

But the comments from a Greater Louisville Inc. subcommittee take issue with multiple aspects of Stone’s analysis, ultimately arguing the study isn’t sound enough to serve as the basis for new city-wide policies. GLI said it would support certain incentives to increase the number of businesses with lighter-colored roofs or parking lots, for instance, but didn’t find the justification for any new regulations.

GLI spokeswoman Alison Brotzge-Elder declined an opportunity to elaborate for this story, saying the organization’s comments speak for themselves.

But for his part, Stone said GLI’s comments miss the mark.

“We very much welcome these kinds of comments — that’s the purpose of having the open comment period,” he said. “My concern is that they misconstrue some really fundamental components of the study.”

In an interview with WFPL News, Stone said the urban heat island analysis is a study and not a plan. He said it would be inappropriate to include such components as a cost-benefit analysis. The study’s lack of any consideration of economic factors was a major point in the GLI comments.

“They characterize in their comments the study as a plan, as if we’ve handed over a blueprint for the city to just run with now. And that’s actually not the case,” Stone said. “This is the foundational data that we would like the city to consider in terms of developing and proposing policies and ultimately formulating a plan. But the study itself is not a plan. It’s simply an analysis of how different types of strategies could cool down the city.”

GLI also criticized the study’s reliance on data from the summer of 2012 — the hottest Louisville summer on record. Stone defended the choice, saying in a region expected to experience an increasing number of above-average summer temperatures, the summer of 2012 is a reasonable basis.

“If you want to get a sense of how effective strategies will be down the road, you need to choose a hot summer,” he said.

In its comments, GLI said it recognizes the urban heat island is a quality-of-life issue. Seemingly without irony, it lauds the city’s public-private partnerships to make Louisville “a hotbed for economic development and a talented workforce.” It adds that the study “forms a basis for beginning a public discussion” but “lacks sufficient analysis to form the basis for policy-making.”

As far as Stone is concerned, his Louisville study is complete.

“I think to suggest that the study is wrongheaded or not in the best interest of the region is taking a very short-term view,” he said. “We know we’re going to need to respond to the challenges of heat, and we also know that it will take many years to do that. So this is something that Louisville needs to get started with right away, and so that’s what the data is there to help support.”

Now, it’s up to Metro government to take the study and the 21 comments it received during the comment period and develop a plan to implement some — or none, or all — of Stone’s recommendations.