Here’s How Sweltering Long Island Stands To Get In 2050

If you thought this weekend was hot, climate change could make things much worse. A new report shows the dire reality many communities face in the future due to extreme temperatures driven by human-caused climate change.

Few areas will avoid the impact of extreme heat by midcentury, according to the report released last week by the Union of Concerned Scientists, a nonprofit advocacy group based in Cambridge, Massachusetts.

Historically, Long Island averages about 5 to 13 days per year where the heat index reaches at least 90 degrees, with Nassau County seeing more hot days than Suffolk. That means that while the thermometer might show a lower temperature, the temperature feels like at least 90 degrees. For heat indices of at least 100, Long Island typically sees only one day per year, and no days that are over 105 or “off the charts,” meaning the heat index was so extreme it surpassed the limits of the National Weather Service scale, which tops out at 127 degrees.

Here are the number of high heat index days Long Island can look forward to down the road, given three different scenarios: slow response to curbing climate change, no response and rapid response.

Midcentury

Slow action

• 90 degree days: 26-36
• 100 degree days: 1-3
• 105 degree days: 1-3
• Off the charts days: 0

No action

• 90 degree days: 36-45
• 100 degree days: 8-15
• 105 degree days: 3-6
• Off the charts days: 0

Late century

Slow action

• 90 degree days: 35-45
• 100 degree days: 6-12
• 105 degree days: 2-5
• Off the charts days: 0

No action

• 90 degree days: 69-76
• 100 degree days: 28-36
• 105 degree days: 14-21
• Off the charts days: 1-2

Rapid action:

• 90 degree days: 28-38
• 100 degree days: 3-9
• 105 degree days: 1-3
• Off the charts days: 0

Should the globe take no action to reduce emissions, the average number of days across the country that feel warmer than 100 degrees will more than double to about 36 by midcentury, the organization found. By the end of the century, that number would increase to 54.

Kristina Dahl, senior climate scientist at the organization and co-author of the report, said the analysis shows a “hotter future that’s hard to imagine.”

“Nearly everywhere, people will experience more days of dangerous heat even in the next few decades,” she said in a news release.

If emissions aren’t reduced, parts of Florida and Texas would see at least five months per year with a heat index of at least 100 degrees by the end of the century. Most of these days would exceed 105 degrees, and many would be so extreme, they’d be classified as off the charts — a condition currently only seen in the Sonoran desert on the border of southern California and Arizona.

“Such conditions could pose unprecedented health risks,” she said.

Many places are unaccustomed to these levels of extreme heat, such as the upper Midwest, Northeast and Northwest, and the ability of people and infrastructure in these places to cope with the new normal is “woefully inadequate,” said Rachel Licker, senior climate scientist at the organization and report co-author.

The Southeast and Southern Great Plains are expected to bear the brunt of the extreme heat, the authors found, and by late century, residents in these areas “may have to significantly alter ways of life,” she said.

“ We don’t know what people would be able and willing to endure, but such heat could certainly drive large-scale relocation of residents toward cooler regions,” said Licker.

Patch national staffer Dan Hampton contributed to this report.