A researcher prepares to take shavings from an ice core sample taken from a glacier in the Pamir mountain range in Tajikistan, at the Hokkaido University Institute of Low Temperature Science, in Sapporo, in northern Japan's Hokkaido prefecture on December 9, 2025. Dressed in an orange puffer jacket, Japanese glacier scientist Yoshinori Iizuka stepped into a storage freezer chilled to minus 50 Celcius to retrieve an ice core. (Photo by GREG BAKER / AFP via Getty Images) / TO GO WITH: Japan-Tajikistan-climate-science-environment-research, FOCUS by Hiroshi HIYAMA

A researcher cuts a slice from an ice core sample taken from a glacier in the Pamir mountain range in Tajikistan, at the Hokkaido University Institute of Low Temperature Science, in Sapporo, in northern Japan's Hokkaido prefecture on December 9, 2025. Dressed in an orange puffer jacket, Japanese glacier scientist Yoshinori Iizuka stepped into a storage freezer chilled to minus 50 Celcius to retrieve an ice core. (Photo by GREG BAKER / AFP via Getty Images) / TO GO WITH: Japan-Tajikistan-climate-science-environment-research, FOCUS by Hiroshi HIYAMA

Slices of ice from an ice core sample taken from a glacier in the Pamir mountain range in Tajikistan are seen in bottles at the Hokkaido University Institute of Low Temperature Science, in Sapporo, in northern Japan's Hokkaido prefecture on December 9, 2025. Dressed in an orange puffer jacket, Japanese glacier scientist Yoshinori Iizuka stepped into a storage freezer chilled to minus 50 Celcius to retrieve an ice core. (Photo by GREG BAKER / AFP via Getty Images) / TO GO WITH: Japan-Tajikistan-climate-science-environment-research, FOCUS by Hiroshi HIYAMA

A researcher drops slices of ice from an ice core sample taken from a glacier in the Pamir mountain range in Tajikistan into a bottle at the Hokkaido University Institute of Low Temperature Science, in Sapporo, in northern Japan's Hokkaido prefecture on December 9, 2025. Dressed in an orange puffer jacket, Japanese glacier scientist Yoshinori Iizuka stepped into a storage freezer chilled to minus 50 Celcius to retrieve an ice core. (Photo by GREG BAKER / AFP via Getty Images) / TO GO WITH: Japan-Tajikistan-climate-science-environment-research, FOCUS by Hiroshi HIYAMA

Researchers cut slices from an ice core sample taken from a glacier in the Pamir mountain range in Tajikistan, at the Hokkaido University Institute of Low Temperature Science, in Sapporo, in northern Japan's Hokkaido prefecture on December 9, 2025. Dressed in an orange puffer jacket, Japanese glacier scientist Yoshinori Iizuka stepped into a storage freezer chilled to minus 50 Celcius to retrieve an ice core. (Photo by GREG BAKER / AFP via Getty Images) / TO GO WITH: Japan-Tajikistan-climate-science-environment-research, FOCUS by Hiroshi HIYAMA

Researchers prepare to take shavings from an ice core sample taken from a glacier in the Pamir mountain range in Tajikistan, at the Hokkaido University Institute of Low Temperature Science, in Sapporo, in northern Japan's Hokkaido prefecture on December 9, 2025. Dressed in an orange puffer jacket, Japanese glacier scientist Yoshinori Iizuka stepped into a storage freezer chilled to minus 50 Celcius to retrieve an ice core. (Photo by GREG BAKER / AFP via Getty Images) / TO GO WITH: Japan-Tajikistan-climate-science-environment-research, FOCUS by Hiroshi HIYAMA

Netherland's King Willem-Alexander visits the Leiden University Medical Center (LUMC) in Leiden on December 16, 2025. (Photo by ANP / AFP via Getty Images) / Netherlands OUT

Netherland's King Willem-Alexander (R) inspects a microscope as he visits the Leiden University Medical Center (LUMC) in Leiden on December 16, 2025. (Photo by Lina Selg / ANP / AFP via Getty Images) / Netherlands OUT