Unusual heat is becoming increasingly common, prompting questions about the causes and potential future trends. According to the National Oceanic and Atmospheric Administration, a heat wave is defined as a period of unusually hot weather lasting two or more days, with temperatures exceeding historical averages for a given area.
What Creates a Heat Wave?
These events form when high pressure systems become dominant, trapping warm air. This causes air to sink and compress, creating what is often described as a “dome of heat” that elevates surface temperatures.
The Role of Climate Change
Scientists have long predicted that human-induced climate change would lead to warmer global temperatures. Dr. David Eisenman, a professor of medicine at UCLA, notes, “We always knew that climate change was going to bring more extreme heat days, and that was going to start earlier in the year,” adding, “And I think we’re seeing that now.”
This trend is particularly noticeable in recent years. Global temperatures have averaged more than 1.5°C above pre-industrial levels for the past three years, and the last decade has been the warmest on record.
While scientists determine long-term temperature changes over timescales of decades, the recent pattern suggests a continuing trend toward more frequent and intense heat events.
Frequently Asked Questions
What exactly defines a heat wave?
The National Oceanic and Atmospheric Administration defines a heat wave as a period of unusually hot weather that lasts two or more days, with temperatures outside the historical averages for a given area.
How do heat waves form?
They form when high pressure systems trap warm air in a particular area, forcing air to sink and compress, creating a dome of heat that increases temperatures at the surface.
Is climate change responsible for more frequent heat waves?
Scientists have long understood that human-induced climate change would cause the Earth to heat up, and evidence suggests that extreme heat days are becoming more common and starting earlier in the year.
As global temperatures continue to rise, will communities be able to adapt to increasingly frequent and intense heat waves?
