City warmth mapping undertaking in NYC finds poor neighborhoods hotter

Poorer neighborhoods are hotter than wealthier ones.

That is the overall result of the New York component of a national project to map urban heat islands. Scientists have long known that urban areas generate heat, but have not yet been able to map it street by street.

On a hot summer day in New York City last July, volunteers swarmed into cars with sensors to track heat and humidity. They traveled from the crowded tenements and truck-lined streets of the South Bronx to the open avenues of Manhattan’s Upper East Side.

The heat trackers told an impressive story. On an afternoon in July, there was at least 7 degrees difference between the South Bronx, one of the poorest neighborhoods in New York City, and the Upper East Side of Manhattan, one of the richest. The difference between the South Bronx and Central Park was even bigger: almost 10 degrees.

This type of heat mapping is becoming increasingly important as climate change causes global temperatures to rise and more people to move to urban areas. According to the United Nations, the proportion of city dwellers will increase from 55% today to 68% by 2050. In addition, as temperatures rise, the overall differences between the hottest and coolest areas increase, exacerbating the class and race divide.

“We get extremely granular data. Street level data. What currently exists is satellite data of where the total of New York City’s streets are, “said Dr. Liv Yoon, researcher at Columbia University’s Earth Institute.

The data can help communities target their financial resources to lower temperatures by building more rooms, adding lighter roofs, leaving more space between buildings and opening more cooling centers during heat waves.

“We want to empower the local citizens and scientists who have participated so that they own the data, because we often hear them go to the authorities and say, ‘We have this problem, but they are often answered with’ You ‘when faced with anecdotes and emotions cannot come to us. We need hard data, “said Yoon.

Heat is the most dangerous natural hazard in cities

Melissa Barber, a native of the Bronx and founder of an activist organization United the South Bronx, has fought for everything from community gardens to redesigning the Bronx waterfront to cool the area. Now she’s working with Yoon, using heat mapping to plead with local officials and property developers to switch.

“As community members who actually fight for justice, social justice and environmental justice, we can now say:“ There is current data that says: ‘We breathe a different air.’ There is current data that says, ‘We see and feel heat differently than anywhere else,’ ”said Barber.

“Areas outlined in historic red certainly have less infrastructure that is conducive to cooling. They have fewer green spaces,” said Yoon, who spoke with CNBC, one of the very few community gardens in the South Bronx – a garden that Barber helped design.

Barber says data will give it more power to transform real estate development in poorer parts of New York City.

“We really need to think about how we shape communities. When we talk about historical injustice and this redlining – there were no parks in this plan. There was no water included in this planning buffers that actually allow us to experience the climate differently did not exist and do not exist for many of our urban communities, “said Barber.

The temperature sensors were provided by Oregon-based CAPA Strategies, a climate data and analysis company that works with the federal government, local communities, and nonprofits.

“It really matters because heat is one of the most insidious killers in cities. It kills more people than any other natural hazard,” said Vivek Shandas, a consultant at CAPA.

Shandas notes that climate change is increasing the stakes and exacerbating the effects of the heat on the local economy, which is now stalling more often due to deadly heat.

“We see a greater heat intensity. We see these heat waves last longer and we see heat waves coming through more often, but we still use a single number to tell us what the temperature is a city or region for, “added Shandas.

New York is one of 12 cities participating in this year’s mapping campaign in partnership with the National Oceanic and Atmospheric Administration.

In hotter climates, male dragonflies lose their trademark type

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Male dragonflies lose their wing pigmentation in hotter climates, researchers report.

Less pigmentation will keep them cool, but could make it difficult to find a partner, according to their new study.

“Our study shows that male dragonfly wing pigmentation evolves so consistently in response to climate that it is among the most predictable evolutionary responses ever observed for a mating-related trait,” says Michael Moore, postdoc at the Living Earth Collaborative at Washington University in St. Louis.

“… male dragonflies may have to adapt to global climate change by developing less wing color.”

“This work shows that mating-related traits can be just as important for the adaptation of organisms to their climate as survival-related traits,” he says.

Many dragonflies have dark black pigment spots on theirs wing which they use to woo potential partners and intimidate rivals.

“Aside from their function in reproduction, a lot of dark pigmentation on the wings can heat dragonflies up to 2 degrees Celsius, a pretty big shift!” Moore says that would be roughly a 3.5 degrees Fahrenheit change. “While this pigmentation can help dragonflies find mates, additional heating could also cause them to overheat in places that are already hot.”

The researchers were interested in whether this additional warming could force dragonflies to develop different wing pigmentations in different climates.

For this study, the scientists created a database of 319 dragonflies species based on field guides and citizen science observations. They examined the wing ornaments shown in photographs submitted to iNaturalist and gathered information about climate variables in the locations where the dragonflies were observed. The researchers also directly measured the amount of wing pigmentation on individual dragonflies from nearly 3,000 iNaturalist observations in a focused group of 10 selected species. For dragonflies in each of these 10 species, the scientists assessed how populations differ in the warm and cool parts of their geographic distribution.

Whether comparing species with hotter and cooler geographic areas or populations of the same species living in warmer areas to cooler areas, the researchers saw the same thing: male dragonflies almost always responded to warmer temperatures with lower wing pigmentation.

Sorting the observations differently, the researchers found that male dragonflies sighted in warmer years tended to have less wing pigmentation than male dragonflies of the same species in cooler years (the database included observations recorded during the 2005-19 period ).

“Given the expected further warming of our planet, our results suggest that the male dragonflies may have to adapt to the global world at some point Climate change by developing less wing color, ”says Moore.

The study includes projections based on global warming scenarios that suggest that pigmentation on male wings will continue to shrink over the next 50 years as the Earth warms.

But the changes do not happen in the same way for both sexes.

“… the consequences are something we don’t know very much about yet.”

“In contrast to the males, female dragonflies do not show any major changes in the change in their wing color with the current climate. We don’t yet know why males and females are so different, but that shows that we shouldn’t assume that the sexes adapt to climate change in the same way, ”says Moore.

Dragonflies have different amounts of pigment on their wings that help males and females of the same species to identify each other. One of the interesting implications of this research is that females may no longer recognize males of their own species if the pigmentation of the male wings develops in response to rapid climate changes and the female pigmentation develops in response to something else.

This could result in them mating with males of the wrong species.

“Rapid changes in pairing-related traits could hinder a species’ ability to identify the right mate,” says Moore. “Although our research suggests that these pigmentation changes are likely to occur as the world warms up, we don’t yet know much about the consequences.”

The study will appear in the Proceedings of the National Academy of Sciences.

Other researchers from Washington University in St. Louis and Saint Louis University contributed to the work.

Source: Washington University in St. Louis