This summer, which is still in its first month, already brings a notable series of early heat waves. Above-normal temperatures affect hundreds of millions of people in our country, Europe and Asia. Monthly and all-time records were broken in at least a half-dozen countries during June. Experts say it's another clear sign of human-caused climate change. Planetary warming from the burning of fossil fuels is intensifying and prolonging heat waves, according to scientists.

In the United States, thousands of records have been shattered from California to the Carolinas. Cities as far north as Minneapolis and Milwaukee topped 100 degrees in June for the first time in years. Parts of Texas hit 113 degrees on July 10 -- "extreme" and "dangerously hot," the National Weather Service said. Rome, the capital of Italy, set a June milestone with a reading of 105 degrees. In Japan, the temperature in a city about 50 miles from Tokyo shot above 104 degrees late last month, the highest June reading ever recorded in that country. That same week, over two dozen places in eastern China observed their hottest day on record for any month. Records also were set in Spain, Germany, Poland, Switzerland, Austria, Norway, Finland, Iran and the Czech Republic – all non-tropical countries of the Northern Hemisphere.

Extreme heat is deadly, ranking as the top weather-related killer in the U.S. in a typical year. There’s also an impact on agriculture and food supplies, energy use and prices, and on ecosystems from drought and wildfires. Moreover, it can also stress power grids, especially in countries struggling with a global energy crunch in the wake of Russia's invasion of Ukraine. Japan asks citizens and companies to reduce electric use as much as possible this summer to ease possible power problems.

U.S. meteorologist says: "There's some pretty extraordinary stuff happening, stuff that's not common at all." --Paul Pastelok, lead long-range forecaster at AccuWeather

European specialist says: "Heatwaves similar to those observed this year are expected to become more frequent and severe in the years to come." -- Carlo Buontempo, director of the Copernicus Climate Change Service in the United Kingdom

American news site says: "Heat waves are a typical summer hazard, but climate change is making them -- along with other extreme weather events -- more dangerous, capricious and fearsome." – Axios, June 30