1 . In order to meet growing food production and energy needs in low-and middle-income countries, solar-powered groundwater irrigation (灌溉) is rapidly gaining ground. More than 500,000 solar pumps (泵) have been set up in south Asia over the last few years and a major expansion is planned across sub-Saharan Africa.

Dustin Garrick, professor in the School of Environment, Resources and Sustainability, along with an international team, examined the trend toward solar pumps as a clear opportunity for boosting agricultural yields and reducing poverty, but the opportunity comes with risks.

While replacing electric or gas pumps with solar-powered irrigation holds the promise of reducing carbon emissions (排放), it is not guaranteed. Farmers who have access to these pumps may expand production of crops or diversify into other activities, which are not emissions neutral. Solar pumps will increase groundwater pumping efficiency, which may be desirable in regions that support such increases, but this could worsen groundwater lessening in regions that are already stressed. The cheap clean energy of solar pumps may lead to increased groundwater development, without necessarily decreasing overall emissions.

Despite these challenges, the clean-energy boost can serve as a stimulus for positive change in water and energy management but will require enhanced regulation and planning in both low-and high-income settings. Garrick and his team advocate for improved data collection initiatives, with a shift from separated to integrated approaches. They suggest using technology to measure water pumping and collecting remotely sensed data to monitor land use changes. As well, regulatory improvements are crucial, with mounting limits for carbon emissions and groundwater lessening established at various levels.

With groundwater management already a difficult challenge, we must act fast to understand the implications of the clean energy boost and poverty reduction acts to avoid these gains being won away by wells running dry. The rapid adoption of solar irrigation intensifies the urgency, demanding adaptation from governments and institutions to sail through these complexities.

2 . Historical accounts often described the now-extinct California grizzly bears as huge beasts ready to attack humans and livestock at any time. But according to a new paper, scientists say the truth might have been less dramatic: The bears ate a mostly vegetarian diet and were smaller than previously described. California grizzly bears once roamed in the Golden State. But European settlers often hunted, poisoned and trapped the creatures. Over time, because of these human activities, the California grizzly population declined. The last reliable sighting of a California grizzly bear occurred 100 years ago in 1924, and the animals disappeared completely sometime after that.

Researchers wanted to get a better understanding of the factors that accelerated the bears’ extinction. They also hoped to gain more insight into the creatures’ behavior, size and diet. To do so, they turned to documents and California grizzly specimens in natural history collections. They measured the animals’ skulls and teeth and analyzed their bones and pelts. The researchers found that California grizzly bears were much smaller than the 2,000 pounds often reported at the time. Historical accounts might not necessarily have been wrong, but they might have only included the largest bears. In addition, analyses of the animals’ bones and skins suggest the bears were primarily eating plants, which stands in contrast to their fear some hyper carnivorous (超级食肉的) reputation. “The bears likely increased meat consumption due to landscape changes coupled with the arrival of livestock,” says study co-author Alexis Mychajliw. However, researchers found the animals still ate a majority vegetarian diet and killed far less livestock than historical accounts suggested.

By digging beyond the bears’ reputation, the researchers gained a more accurate understanding of the California grizzly’s biology and natural history. And since scientists and land managers often rely on historical accounts when reintroducing animals to their former habitats, the study serves as a reminder that those old newspapers and journals do not tell the whole story.