MASSIVE ANTARCTIC glaciers are falling apart, which could spell deep trouble for global sea-level rise. Meanwhile, the Trump administration has added another climate denier to lead an agency that is supposed to follow the science.

The warning on the Antarctic glaciers came last week in a paper by an international group of scientists, including a researcher at the NASA Goddard Space Flight Center. Satellite images show that the Pine Island and Thwaites glaciers, which flow along the Amundsen Sea, are losing integrity along their edges. Over the past decade, crevasses and fractures have appeared in the “shear zones” that restrain their movement toward the ocean. The glaciers are moving more rapidly into the sea.

The scientists warn that the damage appears to be part of a vicious cycle “where initial ice shelf weakening triggers the development of damage in their shear zones, which results in further speedup, shearing, and weakening, hence promoting additional damage development,” exaplains the paper, printed in the Proceedings of the National Academy of Sciences. “This damage feedback potentially preconditions these ice shelves for disintegration.”

The disintegration could herald the collapse over time of the whole West Antarctic ice sheet, which contains enough ice to raise seas over time by some 10 feet — without accounting for other melting ice sheets in, say, Greenland.

A dispassionate look at the pervasive and varied changes the world is seeing leads to only one conclusion: The world is rapidly warming, and humans’ breakneck addition of heat-trapping gases to the atmosphere is the primary driving force.

David Legates — a University of Delaware professor associated with the Heartland Institute, a climate denial think tank — has earned infamy for attacking this conclusion, labeling as “alarmists and charlatans” the thousands of experts who have provided the evidence and the analysis. He argues that human beings are just seeing “natural forces” at work. This is who the Trump administration wants leading its scientific agencies. NPR revealed earlier this month that Mr. Legates has been chosen to be deputy assistant secretary of commerce for observation and prediction at the National Oceanic and Atmospheric Administration, which is responsible for weather and climate observation and prediction.

Mr. Legates’s appointment, which does not require Senate confirmation, threatens to upend an agency that produces some of the best Earth science research in the world — and that has, so far, managed to keep doing credible work even as experts at the Environmental Protection Agency and the Interior Department have been suppressed.

As if the raging fires in the Western United States were not enough to focus minds, both the Antarctica and the Legates news should remind voters that the coming election has almost indescribable importance for the future of the planet. The overwhelming expert consensus is that the world is nearing the point of no return. The world cannot afford another four years of denialism and delay.