On the eve of a midterm election that has focused on little of substance, a United Nations panel issued another grim warning about what matters most of all: climate change.

The report from the Intergovernmental Panel on Climate Change released Sunday said the burning of fossil fuels is causing atmospheric changes that will bring droughts, floods, rising seas and intense heat. That in turn will lead to the extinction of wildlife, loss of crops and social upheavals caused by shortages of food and rising numbers of refugees.

“Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems,” the report found.

Yet for all the apoplectic alarms coming from usually cautious scientists, nations are not changing their energy policies broadly enough or fast enough to prevent a climate crisis. The reports said energy companies are spending $600 billion a year to find more coal and oil deposits. And even as the United States and Europe try to limit emissions, developing nations are increasing them.

The United States should use its advanced technological and economic leverage to focus world attention on climate change. That effort can push forward when international delegates gather in Lima, Peru in a month to set worldwide limits on emissions.