Antonio Guterres, ahead of next week's annual U.N. General Assembly meeting, warned governments that climate changes are proceeding faster than expected and that fossil fuel emissions have already rebounded from a pandemic dip.
Guterres, speaking at the launch of a U.N.-backed document summarizing current efforts in combating climate change, said that recent extreme weather events -- such as Hurricane Ida in America and floods in Western Europe -- have shown that no country is immune to climate-related disasters.
He said that "these changes are only the beginning of worse things to come" and appealed to governments to achieve the Paris climate agreement goals for 2015.
Guterres stated that unless there is an immediate, large-scale, and rapid reduction in greenhouse gas emissions, global warming will not be limited to 1.5 degrees Celsius (2.7 Fahrenheit). "The consequences of this will be disastrous."
Their report, entitled United in Science 21, was based on research from six U.N. bodies as well as scientific organizations. It argued that human-caused emissions, record temperatures, and disasters have a direct relationship. This includes "billions of hours that are lost to heat alone."
They noted that further impacts will be inevitable due to the long-lasting effects from many of the emissions already released into our atmosphere.
The authors stated that even with the most ambitious efforts to reduce greenhouse gas emissions, sea level rises will continue and threaten low-lying coastal populations around the world.
Jonathan Overpeck from the University of Michigan, who was not part of this report, stated that scientists have already said this but it is important: "The condition is getting worse, we know why, and we know how we can solve it in ways which leave us and future generations with a better and healthier world."
Guterres encouraged governments to present more ambitious plans to reduce emissions at the U.N. Climate Summit in Glasgow. This included a commitment not to add more greenhouse gases to the atmosphere by midcentury than can be removed.
Michael Mann, a climate scientist from Pennsylvania State University, stated that he agrees with the report's urgency message but questions some of its more stark warnings.
He said that the 1.5C threshold, which was agreed to in Paris, didn't apply to specific years. Some of these years can be extremely hot due to other factors.
Mann stated that Mann's misleading framing "unnecessarily feeds fears that the public has that somehow we have already crossed that threshold, and that it is too late to stop." We haven't. It isn't."
He also pointed out that the drop in carbon emissions during the pandemic could have been interpreted as a sign that substantial cuts are possible if whole economies are shifted away from fossil fuels.
Mann stated that the United States, Britain, and the European Union had already pledged to help prevent dangerous global warming.
Kim Cobb, an Earth and Atmospheric Sciences professor at Georgia Tech was also reassured that the 1.5C target can be achieved.
She stated that the new report was a stark reminder of how different the emission pathways to reach the target and reality are. "We are clearly way off the course," she said.