This heatwave is a climate omen. But it’s not too late to change course | Michael E Mann and Susan Joy Hassol

The warming of the planet - including the most up-to-date data for 2023 - is entirely consistent with what climate modelers warned decades ago

Thirty years ago, the world's nations agreed to prevent dangerous human interference with the climate system. But what is dangerous climate change"? Just turn on the television, read the headlines of the morning paper or view your social media feeds. For we are watching it play out in real time this summer, more profoundly than ever before, in the form of unprecedented floods, heatwaves and wildfires. Now we know what dangerous climate change looks like. As has been said of obscenity, we know it when we see it. We're seeing it - and it is obscene.

Scorching temperatures persist across Europe, North America and Asia, as wildfires rage from Canada to Greece. The heat is as relentless as it is intense. For example, Phoenix, Arizona, has broken its record of 18 consecutive days above 110F (43.3C). Even the nights, generally relied upon as a chance to recover from the blistering days, now offer little relief: for more than a week, nighttime temperatures in Phoenix have exceeded 90F (32.2C). Meanwhile, severe and deadly flooding has stricken South Korea, Japan, and the north-east United States, from Pennsylvania to Vermont.

Michael E Mann is a professor of earth and environmental science and the director of the Center for Science, Sustainability and the Media at The University of Pennsylvania. He is author of the forthcoming book Our Fragile Moment: How Lessons from Earth's Past Can Help Us Survive the Climate Crisis

Susan Joy Hassol is the director of Climate Communication. She publishes Quick Facts on the links between extreme weather and climate change