Baby it’s hot outside!

Wednesday, July 28, 2021
August.  It’s one of the hottest months of the year and getting hotter.  In NJ, continued warming is projected with the state’s average annual temperature expected to rise another 4.1 to 5.7 degrees Fahrenheit by 2050 (2020 New Jersey Scientific Report on Climate Change). Heat, especially in our urban communities, is difficult on everyone but especially so for pregnant women and their unborn babies. When a woman is pregnant, her body is already working hard to keep her and the developing baby healthy, so adding the extra work of keeping cool can cause major body stress.  In communities of color, high temperatures are one of several factors that drive higher rates of premature deliveries, stillbirths and other dangerous pregnancy outcomes.1  

Recognizing this, many states have launched initiatives (such as Nurture NJ) to reduce infant and maternal mortality and ensure equity in care and outcomes for mothers and infants of all ethnic groups.  Did you know, however, that trees can play a positive role in these initiatives too? Urban trees are found to promote higher birth weights and support good health in newborn babies.2  Healthy urban tree canopies provide shade and water transpiration that can mitigate the warming effects resulting from the lack of tree canopy and green space (known as the urban heat island effect) often found in our urban communities.  Moreover, the air quality in our urban areas, especially during August, can also be unhealthy; exposure to air pollution during pregnancy can increase a woman’s risk of premature birth and low birthweight. 3    The good news is that while the relationship between trees and air pollution is complicated, overall trees have been shown to have a positive effect on reducing air pollution.
Much research has been conducted recently regarding environmental justice issues resulting from the uneven, unjust, or inequitable distribution of green spaces across some urban areas.4  On September 18, 2020, landmark environmental justice legislation was signed into law in NJ. (P.L. 2020, c.92) to address many environmental justice issues.  This legislation was followed by the NJ Department of Environmental Protection’s (NJDEP) issuance of new guidance for all state agencies regarding environmental justice. Promoting tree canopy to reduce the urban heat island effect and green infrastructure are just two of the considerations that while not specified in the recent EJ law, are included as focus areas in this guidance.
So if you find yourself feeling the August heat, pregnant or not, drink plenty of water, be mindful of the air quality, wear fabrics that breath, and move to a cooler place if you can (perhaps under a tree?). After all, trees cool the city by up to 10°F by shading our homes and streets and releasing water vapor into the air through their leaves. (Arbor Day Tree Facts)  Additionally, according to New Jersey’s Global Warming Response Act 80x50 Report, “shaded surfaces may be 20-45F cooler than the peak temperatures of unshaded materials.

1Chelsea Harvey, 2020, ‘Heat, pollution raise pregnancy risks, especially for blacks,’ GREENWIRE, July 19, 2020

2Dzhambov, Angel M., Donka D. Dimitrova, and Elena D. Dimitrakova. 2014."Association Between Residential Greenness and Birth Weight: Systematic Review and Meta-analysis." Urban Forestry & Urban Greening 13 (2014): 621-29. Elsevier. Web. 12 January 2016.

By Terri Slack, NJ Urban & Community Forestry Program, NJ Department of Environmental Protection