WHAT IS A HEATWAVE?
In the Media over the past few weeks all there has been is talks of heatwaves and mini heatwaves but what is a heat. In this article you will find out every thing you need to know about heatwaves.
A heat wave is an extended period of unusually high temperatures and often high humidity that causes temporary modifications in lifestyle and may have adverse health effects on affected human populations. There is no universal temperature threshold for a heat wave, as social and cultural practices largely define perceptions of and responses to heat. In parts of the world where summer conditions often exceed the physiologic threshold—the point at which adequate removal of heat from the body is impeded—behavioral changes such as taking siestas and
Decreasing activity levels throughout the day and housing modifications that increase air movement allow people to withstand higher temperatures for longer periods than people living in cooler climates. Thus, what might be considered a heat wave in a normally cool region would not be considered extreme weather in a warmer region.
The World Meteorological Organization (WMO) defines a heat wave as a period during which the daily maximum temperature exceeds for more than five consecutive days the maximum normal temperature by 9°F (5°C), the “normal” period being defined as 1961–1990. Because of global warming, the frequency, duration, and severity of heat waves are predicted to increase in most parts of the world. The impacts on human health, regional economies, and ecosystems may be significant.
A heat wave can influence the economy and infrastructure of an affected region. The large draw on electric power sources due to increased air conditioning causes electricity demand to rise sharply. Power outages then result, creating blackouts that leave many homes and businesses without power. Ruptured water lines and buckled roads are also caused by excessive heat. Finally, heat waves that occur during periods of drought can contribute to wildfires that destroy homes, businesses, and forests.
According to the Intergovernmental Panel on Climate Change (IPCC), heat waves have increased in duration since 1950. Global climate models created by scientists at the National Center for Atmospheric Research and by a number of other groups agree that heat waves in much of the world, including most of Europe and North America, will become more intense, frequent, and of longer duration in the second half of the twenty-first century.