MERIDA, Venezuela (AP) — Blackouts shut off the refrigerators where the scientists keep their lab samples. Gas shortages mean they sometimes have to work from home. They even reuse sheets of paper to record field data because fresh supplies are so scarce.

As their country falls apart, a hardy team of scientists in Venezuela is determined to transcend the political and economic turmoil to record what happens as the country's last glacier vanishes.

Temperatures are warming faster at the Earth's higher elevations than in lowlands, and scientists predict that the glacier — an ice sheet in the Ande...