Tiempo Climate Newswatch

Both China and the United States are making available cooling centres, with air conditioning and water, for people stressed by the severe heatwaves affecting parts of the two countries. In China, areas of the north and centre of the country have been experiencing temperatures reaching 40°C, hospital wards have been crowded with victims of heat-related illnesses and overheated vehicles have caught fire. Beijing has experienced the highest single day of water use since 1910. Five hundred cooling shelters have been opened in Guangzhou in southern China.

In the eastern United States, cooling centres in schools and neighbourhood buildings have been opened in New York and Philadelphia. The New York City government has advised residents to visit the cooling centres or spend the day at the mall, museum or movies. Residents are also advised to restrict strenuous activity to between the hours of four and seven in the morning. Heather Buchman of AccuWeather warned that "in addition to putting stress on people and their health, the intense heat will also place a higher demand on power grids due to increased usage of air conditioning. Power outages could result in some communities, putting people at an even greater risk for developing heat-related illnesses."

Solar Impulse has flown for over 24 hours, powered overnight by energy harvested by its 12,000 solar panels during the previous day. Pilot André Borschberg described the flight, over Switzerland, as the most incredible of his 40 years' flying - "just sitting there and watching the battery charge level rise and rise, thanks to the sun." After dark, the plane flew at a height of 6,500m at a speed of 23 knots.

The aim of the project is to demonstrate that, in theory at least, the plane, which has an airliner-scale wingspan, could stay in the air indefinitely. "We are on the verge of the perpetual flight," said project chief Bertrand Piccard. International Air Transport Association commented that, while solar power is unlikely to be the solution for commercial aviation, "after today’s flight, nobody, ever again, can say that carbon-free flight is impossible. The industry’s job is to achieve the same for a plane carrying 400 people."

Lack of attention to the ethical dimension is stifling progress toward sustainability, according to two American researchers. The sustainability debate, write John Vucetich of Michigan Technological University and Michael Nelson of Michigan State University in the journal Bioscience, has "almost entirely neglected" the ethical dimension. They consider the issue of ethics a vital component in the teaching and research of sustainability.

According to Vucetich and Nelson, the most widely appreciated definitions of sustainability - roughly, meeting human needs in a socially-just manner without depriving ecosystems of their health - could mean anything from "exploit as much as desired without infringing on the future ability to exploit as much as desired" to "exploit as little as necessary to maintain a meaningful life." "Handling these disparate views is the inescapable ethical crisis of sustainability," said Vucetich. "The crisis results from not knowing what we mean by value-laden terms like 'ecosystem health' and 'human needs,'" Nelson commented. "In other words, is ecosystem health defined by its ability to meet human needs only, or does ecosystem health define the limits of human need?"