WASHINGTON, D.C. — Increases in potentially lethal heat driven by climate change will affect every state, including Connecticut, in the decades ahead, according to a new report by the Union of Concerned Scientists.

The report released Tuesday found that historically Connecticut has averaged about 10 days per year with a heat index above 90 degrees Fahrenheit. That would increase to 40 days per year on average by 2050 if no action is taken to reduce heat-trapping emissions. The days with a heat index above 100 degrees Fahrenheit would increase to 13 per year on average and cities like Bridgeport, Danbury, and New Haven would experience the highest frequency of these days.

Tracy Babbidge, who works in the air control division of the Department of Energy and Environmental Protection (DEEP), said the study serves as a “good reminder for us to review that we are doing everything we can and should be doing to deal with the issues of climate change and reducing emissions.”

Babbidge noted that Connecticut is enrolled in the Global Warming Solutions Act, which many refer to as Connecticut’s central climate commitment. It requires the state to reduce its total greenhouse gas emissions to at least 10% below 1990 levels by 2020, and to at least 80% below 2001 levels by 2050.

Babbidge said that beyond the scary temperature numbers the report predicts, it is important to focus on the impact that “extreme heat and high ozone levels can have on our most vulnerable populations.”

She said that’s why opening cooling centers — which many towns in Connecticut are planning to do Wednesday as the predicted heatwave hits — are important pre-emptive steps.

The report released Tuesday states that by the end of the century, with no action to reduce global emissions, parts of Florida and Texas would experience the equivalent of at least five months per year on average when the “feels like” temperature exceeds 100 degrees Fahrenheit, with most of these days even surpassing 105 degrees.

The analysis calculated the frequency of days with heat index thresholds above 90 degrees Fahrenheit — the point at which outdoor workers generally become susceptible to heat-related illness — as well as above 100 and 105 degrees Fahrenheit, when the National Weather Service (NWS) generally recommends issuing heat advisories and excessive heat warnings, respectively.

The number of high heat-index days was calculated by averaging projections from 18 high-resolution climate models between April and October. The report looked at these conditions for three possible futures.

The “no action scenario” assumes carbon emissions continue to rise and the global average temperature increases nearly 8 degrees Fahrenheit above pre-industrial levels by century’s end.

The “slow action scenario” assumes carbon emissions start declining at midcentury and the global average temperature rises 4.3 degrees Fahrenheit by century’s end. In the “rapid action scenario,” global average warming is limited to 3.6 degrees Fahrenheit — in line with the Paris Agreement.

The Paris Climate Agreement was signed in December 2015, where 195 countries adopted the first universal, legally binding global climate deal.

The agreement sets out a global action plan to put the world on track to avoid dangerous climate change by limiting global warming to well below 3.6 degrees Fahrenheit and pursuing efforts to limit it to 2.7 degrees Fahrenheit.

The report states if the goals of the Paris Climate Agreement is met and future global average warming is limited to 3.6 degrees Fahrenheit, by late century the United States would see half the number of days per year, on average, with a heat index above 105 degrees Fahrenheit, and almost 115 million fewer people would experience the equivalent of a week or more of “off-the-charts” heat days.

Connecticut is a member of the U.S. Climate Alliance, a bipartisan coalition of governors committed to reducing greenhouse gas emissions consistent with the goals of the Paris Climate Agreement.

On June 1, 2017, U.S. President Donald Trump declared his intention to pull the United States out of the Paris Climate Agreement. The U.S. can’t exit the agreement until Nov. 2020, the day after the next presidential election.