As part of the Intergovernmental Panel on Climate Change (IPCC), researchers with the United Nations released a new report on Monday outlining the stark global impacts of the crisis.

The study features contributions from 234 authors representing 66 countries, and marks the first such large-scale assessment of climate science and policy in the last eight years, according to BBC News. 

“This report is a reality check,” IPCC Working Group Co-Chair Valérie Masson-Delmotte stated. “We now have a much clearer picture of the past, present and future climate, which is essential for understanding where we are headed, what can be done, and how we can prepare.”

The “unequivocal” data show how rapidly Earth is approaching the widely agreed-upon warming threshold of 1.5 degrees Celsius. The IPCC notes that there are already enough greenhouse gases in the air to reach that point, but the smog and pollution created by those same fossil fuels are paradoxically keeping their own heating effects in check. Governments must immediately enact broad emissions-targeted changes, the report states, or limiting the global temperature increase to 1.5–2 degrees Celsius will be “beyond reach.”

Additionally, the landmark study demonstrates a direct causal link between the atmospheric warming caused by human activity and particular extreme weather events – like the severe drought plaguing the U.S. West, and the wildfires that have blazed there and abroad – which will grow more frequent and severe as temperatures continue to rise.

The crisis may pose no greater threat, however, than to the water that makes up 71 percent of Earth’s surface. Warming has already caused a significant decline in ocean oxygen levels, altered rainfall cycles, and raised sea levels, which most scientists now predict to climb about a half foot more than previously estimated, according to the Atlantic.