UN Secretary-General António Guterres warned that the "ticking climate time bomb is nearing its explosion moment" and urged wealthy nations on Monday to reduce emissions soon, following a new assessment from scientists indicating that there is no time left to waste in addressing climate change. Guterres explained that "the rate of temperature rise over the past half-century is the highest in 2,000 years... carbon dioxide concentrations are at their highest levels in at least two million years. The ticking climate time bomb is nearing its explosion." In a recorded speech, he described the "Sixth Assessment Report" from the Intergovernmental Panel on Climate Change as a "survival guide for humanity" and urged developed countries to commit to achieving net-zero emissions by early 2040.