'We Are Sleepwalking Towards the Edge,' Says Greta as UK Sees Hottest Day on Record

As the United Kingdom endures its hottest day on record amid Europe's unprecedented and ongoing heatwave, Swedish climate activist Greta Thunberg warned Tuesday that the worst is yet to come--unless people around the world work together to dislodge the profit-maximizing economic system that is endangering life on Earth.

"This is not 'the new normal,'" Thunberg wrote on social media. "The climate crisis will continue to escalate and get worse as long as we stick our heads in the sand and prioritize profit and greed over people and planet. We are still sleepwalking towards the edge."

Thunberg's comments came as temperatures in Britain exceeded 40oC (104oF) for the first time in recorded history and continued to rise.

Such life-threatening conditions are consistent with climate scientists' long-standing and oft-repeated warnings that heatwaves, wildfires, and other extreme weather disasters will increase in frequency and intensity as long as greenhouse gas emissions, driven primarily by the burning of fossil fuels, continue to soar.

As The Guardianreported:

Hannah Cloke, a professor of hydrology at the University of Reading, said the record was a "grim milestone" and part of a "slide into unknown territory for humanity as we heat our planet." She urged "every politician who is calling for a watering down of climate policy to explain their thinking."

Nigel Arnell, a professor of climate system science at Reading, said emergency heat health alerts like the one in place for much of England could happen every two to three years by the 2050s, and more frequently if the world remains on track for temperatures to rise by over 2oC by the end of the century.

It's not just the U.K. that is being scorched. Large swaths of the Northern Hemisphere--from Europe to Asia to North Africa and North America--are suffering under the weight of brutal heatwaves and devastating wildfires. More than 1,100 heat-related deaths have been reported this month in Portugal and Spain alone.

Thunberg's stark warning about the world's current trajectory toward an even hotter future echoed Monday's unequivocal message from United Nations Secretary-General Antonio Guterres.

"We have a choice," said Guterres. "Collective action or collective suicide. It's in our hands."

"We need a concrete global response that addresses the needs of the world's most vulnerable people, communities, and nations," he added. "This has to be the decade of decisive climate action."