The climate is changing rapidly, but Smart surface technologies can help keep our cities cool — improving livability, health, and equity.
Worldwide temperature trend
"Earth’s long-term warming trend can be seen in this visualization of NASA’s global temperature record," says NASA, "which shows how the planet’s temperatures are changing over time..."
Source: NASA News, NOAA. Credit: NASA’s Scientific Visualization Studio/Kathryn Mersmann.
Hot SUMMER days and nights ARE BECOMING MORE COMMON ACROSS THE UNITED STATES
It is getting much hotter and staying hot longer. The "Hot Days and Nights are Increasing in The United States" chart shows the percentage of the contiguous US that experienced unusually hot summer temperatures over time. The divergence in the blue trend lines shows that temperatures are not falling during the night as much as they did historically. High temperatures through the night limit how much people, and city surfaces, can cool down before sunlight heats them the following day. This exacerbates heat-related health risks, raises energy costs, and makes cities increasingly less livable (see 'Urban Heat Islands' section below).
For full 100-year data, see EPA (I), NOAA, and other select sources on climate change-related heating: Scientific American (I), Scientific American (II), EPA (II), Climate Central (I), Climate Central (II), Delivering Urban Resilience.
Rising temperatures will have major health impacts
In addition to causing physical discomfort, heat stress, heat stroke, and potentially death, extreme heat also has a range of deleterious long-term health impacts. As is detailed in this Guardian article, regular or acute exposure to high temperatures can cause major and lasting organ damage. Research has also linked extreme heat with increased hospital visits, worsened mental health issues, and higher rates of violence.
URBAN HEAT ISLANDS
URBAN AREAS ARE HOTTER THAN THEIR SURROUNDINGS DUE TO THE MATERIALS USED IN BUILDING URBAN INFRASTRUCTURE
Urban areas have become much hotter because dark roads, pavements, and roofs have replaced trees and green spaces.
The EPA warns, "Heat islands can affect communities by increasing summertime peak energy demand, air conditioning costs, air pollution and greenhouse gas emissions, heat-related illness and mortality, and water quality."
Cities are hotter than their surroundings because: (1) there are few downtown trees and little vegetation to absorb heat (and pollution and rainfall), and (2) roofs, roads, and sidewalks absorb most of the sun’s heat (rather than reflecting it away) and then radiate that heat into buildings and city air.
Reducing emissions is critical to fight global warming. Smart Surface strategies both slow global climate change and provide large urban cooling, health, and economic benefits. Find out how.
HEAVY RAINS ARE BECOMING MORE COMMON
MORE EXTREME RAINS MEANS GREATER FLOOD RISK
Hurricanes and extreme rain events have become more frequent and widespread. The blue chart shows percent change in very heavy precipitation in the United States from 1958 to 2012.
Smart Surfaces help to reduce flood risk by allowing rainwater to be absorbed back into the ground instead of running off into storm drains which can overflow, or into rivers which can pollute marine environments and/or drinking water sources. By implementing standard Smart Surface policies, we can reduce these risks, and save money. Find out how.
Observed Change in Very Heavy Precipitation. Source: The Third National Climate Assessment. Also see: the EPA Green Infrastructure Guide for Municipal Operations.