Q: Could the melting of ice at the poles affect the tilt and rotation of the Earth?

Melting ice from polar regions is one of numerous processes that affect the speed of Earth’s rotation, said James Davis, Lamont Research Professor at the Lamont-Doherty Earth Observatory of Columbia University.

It also affects the tilt of the axis of rotation, by about 1 degree per million years, he said, and NASA has measured alterations in the gravity field as well.

“Melting polar ice enters the oceans as water,” Davis said, “and one effect of this process is to move mass around on Earth’s surface.” The shifting weight also causes material to move around inside the planet, thereby changing its shape. The combined effect of these motions, he said, “is to make Earth less round and more squished from pole to pole, compared to the equator.”

This net mass shift slows the Earth’s spin rate, just as a spinning ice skater pushes out her arms to slow down, Davis said. That has the effect of lengthening the day: Recent calculations indicate that loss of mass in Greenland and the Antarctic makes the day about 0.6 millisecond longer per century.

At the same time, however, Earth is still changing shape in response to the massive melting from 23,000 to 10,000 years ago – coincidentally decreasing the day by about the same 0.6 millisecond per century.

Q: Do animals suffer from sunburn? If so, is it just the hairless ones, or are domestic animals like dogs and cats also at risk?

“Animals can get sunburn, just as people do, from too much sun exposure,” said Dr. Paul Calle, chief veterinarian at the Wildlife Conservation Society in the New York City borough the Bronx.

“Wild animals are marvelously adapted to their environment, so those in areas with lots of sunlight usually have scales, feathers or fur to protect them,” he said. “They also retreat to burrows, shady areas or water; wallow in water or mud; or spray dust or water on themselves when the sun is at its peak.”

Wild animals that are sick, injured or in distress, like stranded whales or dolphins, can develop serious sunburn because they cannot protect themselves from excessive exposure to the sun, Calle said.

Domestic animals, including dogs and cats, that have short hair, thin coats of hair or pale skin are at greater risk of sunburn, he said. Just like people, they also can develop complications like skin cancer, especially melanoma.