Axios

A massive survey of European waters has found that across the continent, climate change has caused flood times to shift — sometimes by several weeks.

Why it matters: Major shifts in flooding could have big impacts for local water management. "It opens up a lot of questions about how these changes in flood timing could interact with other kinds of processes that impact people," Anna Michalak, an earth scientist at the Carnegie Institution for Science in Stanford who was not involved in the study tells Axios. "Societies and ecosystems have adapted to the average within-year timing of floods. We're used to them coming at a certain time of year, and our land management practices have evolved to respond to that."

Tesla has asked state government permission to test-drive a caravan of electric, autonomously driven semi-trucks in Nevada, per Reuters' Marc Vartabedian.

CEO Elon Musk had already said he would unveil an electric semi-truck in September, and the new details help to fill in his possible thinking about the economics for a vehicle that would require a colossal battery: Researchers consulted by Axios in April estimated that the battery for a semi-truck would weigh three tons and cost about $70,000.

That could be prohibitive when you add in the pricetag for the semi-truck itself (the estimated cost for first-generation self-driving cars is about $300,000, so a truck would be much more), but a truck fleet company would be able to more easily absorb the expense if drivers were not necessary.

What it means: Since autonomous technology is not yet ready, and may not be until the 2030s, Tesla's idea may be to have a human-driven truck as the lead vehicle, and a caravan of semis behind, each programmed simply to follow the one in front of it, with no humans inside.