Large daily temperature fluctuations can harm human health

This summer has shown how quickly high temperatures can pose serious health risks record-breaking heat waves that claims thousands of lives worldwide.

However, it is not alone high and low temperatures that case. How many degrees the temperature fluctuates within a day – the daily temperature variation– itself poses health risks.

Research has shown that days with greater than normal temperature fluctuations can increase flare-ups of asthma and hospitalizations for respiratory tract And heart and vascular diseaseleading to a generally higher mortality rate than normal. One study, based on data from 308 cities between 1972 and 2013, estimates that 2.5% of deaths at that time could be attributed to large diurnal temperature variations.

Although humans can live in a wide range of environmental temperatures, a dramatic temperature shift can tax multiple systems in the body, including the immune, musculoskeletal system And cardiovascular systems. It may be especially stressful for very young people And older individualswhich are generally more vulnerable to harsh climates.

We daily temperature fluctuations are mapped at the neighborhood level across the US to get a better sense of where these temperature swings are greatest and who is most affected. The results highlight how poverty and a legacy of discriminatory practices have led racial minorities and low-income residents in neighborhoods to experience more dramatic temperature differences throughout the day.

What affects temperature fluctuations?

In some regions, such as the southwestern US, large nighttime temperature swings are more common, but they can also vary over short distances depending on the landscape and what is known as the urban heat island effect.

For example, the ocean can mitigate rapid temperature changes because water can absorb a lot of heat before it becomes hot. The bigger one Los Angeles area is an example of this. Santa Monica, a coastal community in Los Angeles County, has much smaller temperature fluctuations than more inland neighborhoods in the county, such as downtown Los Angeles.

Green space, such as wooded parks, can also reduce temperature fluctuations. Urban trees and vegetation can keep neighborhoods cooler, reducing temperature fluctuations.

Who faces the greatest temperature fluctuations?

Using NASA satellite data from 2000 to 2017, we compared daily temperature variation with that from the US Census Bureau. American community research demographic data at various censuses how race and ethnicity, income, and age influenced exposure to daily temperature fluctuations in all 50 states.

We found that of the three demographic factors, exposure to daily temperature variations is the most unequal based on race and ethnicity, followed by income. Age mattered least.

In the state with the greatest inequality, Rhode Island, Hispanic and Black populations experienced average daily temperature variations of 31.2 degrees Fahrenheit (17.3 degrees Celsius) in May, while the average daily temperature variation for white populations was 25.8 F (14.3 C). ). That’s a difference of 5.4 F (3 C) between the groups.

The contrast between low- and high-income groups in Rhode Island was 28.6 F (15.9 C) compared to 24.5 F (13.6 C), a difference of 4.1 F (2.3 C). The difference was negligible between age groups, at 1.8 F (1 C).

Among the 50 states, we saw significant differences by race and ethnicity in 46 states, by income in 39 states, and by age in 15 states. In general, The daily temperature fluctuations were the greatest in the western states, especially in late spring and summer.

The fact that minority populations disproportionately live in neighborhoods with greater temperature variations confirms yet another dimension of inequality in vulnerability to climate change.

Temperature fluctuations are increasing as a result of climate change

There is also evidence that temperature fluctuations will become more dramatic over time. Of the 1950s to 1980sData shows that temperature fluctuations are decreasing worldwide. However, since the 1990s, research shows that temperature fluctuations may have increased that affects all life on earth.

Studies suggest that these temperature fluctuations will continue to broaden as greenhouse gas emissions, largely due to the burning of fossil fuels, continue to increase global temperatures. And with those increases will come more premature deaths. According to the Intergovernmental Panel on Climate Change’s highest emissions scenario (RCP 8.5), which outlines conditions in a world that burns increasing amounts of fossil fuels, future temperature fluctuations are expected to increase by as much as 2.9°F (1.6°C) by the end of the century.

There are ways to reduce the risk, starting with reducing greenhouse gas emissions from vehicles, power plants, livestock and other sources.

Communities can also take steps to reduce the exposure of low-income and minority neighborhoods to temperature fluctuations by increasing tree cover and using light coatings on roofs to reflect heat away from buildings. They can also offer assistance programs to help people who otherwise cannot afford to install or power cooling or heating equipment.

This article is republished from The conversation under a Creative Commons license. Read the original article.