What does Revelation 16:8 mean?

The fourth angel pours his bowl onto the sun with the result that the sun's temperature becomes so high that the sun's rays scorch people. There is an area in California in the United States with such high temperatures that it is called Death Valley. It's not uncommon for sunlit rocks and paved surfaces around the world to become hot enough to cause serious burns. But when the fourth angel delivers his bowl judgment, striking the sun, temperatures everywhere on earth may far exceed those of Death Valley.

This verse uses the Greek root word didōmi, which implies something that is "allowed" or "granted." This might mean that the sun, itself, is not going to be changed so much as earth will be more susceptible to it. In other words, this bowl judgment might mean something previously restraining the sun's potency—such as the ozone layer—will be crippled, "allowing" the sun to scorch the earth.

Looking at all these environmental judgments together, one can see how they could combine to create extreme conditions. Death and decay from earlier judgments can interfere with earth's natural defenses against solar radiation and temperature change. In this judgment, life-threatening sunburn and perhaps skin cancer may become common. What's described here might be thought of as an extreme form of global warming. Glaciers may melt and become raging floods. Drought and heat may contribute to crop loss, causing further famine and starvation. Grasslands would become deserts, wildfires would rage out of control. Pushed too hard, air conditioners and other machines would break down, causing massive deaths from heat exhaustion and sun stroke.

As a worldwide problem, even believers will suffer from the furnace-like heat of the sun. Revelation 7:16 holds God's promise that the believers that come out of the great tribulation will never experience the sun's scorching heat again.