In just 50 years, 2 billion to 3.5 billion people, mostly the poor who can’t afford air conditioning, will be living in a climate that historically has been too hot to handle, a new study says. With every 1 degree increase in global average annual temperature from man-made climate change, about a billion or so people will end up in areas too warm, day-in, day-out, to be habitable without cooling technology, according to ecologist Marten Scheffer of Wageningen University in the Netherlands, co-author of the study. How many people end up at risk …

An alliance of world leaders is holding a virtual summit Monday hoping to drum up billions of dollars to fund research into a vaccine for the new coronavirus as well as develop better treatments and more efficient testing.Governments have reported around 3.5 million infections and more than 247,000 deaths from the virus, according to a count by Johns Hopkins University. But deliberately concealed outbreaks, low testing rates and the strain on health care systems mean the true scale of the pandemic is much greater.People in many countries across the globe, …

Goodbye lockdown, hello smartphone. As governments race to develop mobile tracing apps to help contain infections, attention is turning to how officials will ensure users’ privacy. The debate is especially urgent in Europe, which has been one of the hardest-hit regions in the world, with nearly 140,000 people killed by COVID-19. The use of monitoring technology, however, may evoke bitter memories of massive surveillance by totalitarian authorities in much of the continent.   The European Union has in recent years led the way globally to protect people’s digital privacy, introducing …