The U.S. government just released a report confirming everything we know about climate change.
On Friday, the U.S. Global Change Research Program — supported by 13 federal agencies — officially released the fourth National Climate Assessment. Its conclusion: Humans are, without doubt, the cause of global warming.
Eyebrow-raising statements from the report include:
- “This period is now the warmest in the history of modern civilization.”
- “It is extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming … there is no convincing alternative explanation supported by the extent of the observational evidence.”
But perhaps the most remarkable item in the report — which is saying a lot, considering the sheer number of alarming graphs and charts crammed in there — is the acknowledgement of just how much we still don’t know.
In a section headlined “There is a Significant Possibility for Unanticipated Changes,” the study authors outline the scientific uncertainty around things like feedback loops and tipping points. Essentially, there is so much human-influenced ecosystem change of which we aren’t yet aware — and so much that is unprecedented — that we can expect “abrupt and/or irreversible” surprises. The problem being, of course, that we don’t know what those surprises are.
Dig into the full report here.