Twenty-eight years after Unit 4 at the Chernobyl power plant in what was then Soviet Ukraine erupted into a volcano of radioactivity, its name has become synonymous with the nightmarish side of nuclear power. It is also the site today of an extraordinary international project, the construction of a vast steel shield to cover the leaky concrete ‘‘sarcophagus’’ in which the highly radioactive remains of the reactor are to be entombed for at least 100 years.

The construction of what is called the New Safe Confinement by an international team of engineers and workers is already almost a decade behind schedule, and current plans call for it to be completed by 2017. Given the decrepit state of the sarcophagus, it is a race against time. Add to that the uncertainty and near-bankruptcy of Ukraine, and Chernobyl continues to stand as a fearsome testament to the dangers of nuclear power — more powerful than Three Mile Island before it or Fukushima after it.

Yet it is also noteworthy that these civilian nuclear disasters did not and have not overcome the allure of nuclear power as a source of clean and abundant energy. Only Germany succumbed to panic after the Fukushima disaster and began to phase out all nuclear power in favor of huge investments in renewable sources like wind and sun. One consequence has been at least a temporary increase in greenhouse emissions as Germany has been forced to fire up old coal- and gas-powered plants.

The dangers of nuclear power are real, but the accidents that have occurred, even Chernobyl, do not compare to the damage to the earth being inflicted by the burning of fossil fuels — coal, gas and oil. The latest dire warning from the Intergovernmental Panel on Climate Change should leave no doubt that reducing carbon emissions must be an urgent priority and that nuclear energy must be part of the mix.