How does it relate to climate change?
Even a small increase in average temperature caused by climate change can increase the likelihood of extreme heat and heat waves. Heat waves can have serious health consequences, especially for the elderly, young children, the poor and people with pre-existing health problems, such as asthma or heart disease.
The heat wave of August 2003 killed over 14,000 (mostly elderly) in France and 2,000 in England and Wales. In the month of July 1995, only in the city of Chicago, Illinois, USA, which experienced a heat wave, over 700 people died.
Excessive heat can also kill or damage crops and livestock, and can lead to power outages, due to high demand for air conditioning that overloads the electrical grid.
What is currently happening?
Climate change has increased the likelihood of more frequent and more severe heat waves, particularly affecting urban areas, where the urban heat island effect increases susceptibility to heat-related health impacts.
What lies ahead?
Heat waves are expected to become more frequent, longer and more intense in the coming years. The number of extremely hot days is predicted to increase almost all over planet earth.
How certain is the science?
Scientists are very confident that heat waves and other extreme heat events are and will continue to become more frequent and intense due to climate change.