The scientific consensus that humans are causing global warming is likely to have passed 99%, according to the lead author of the most authoritative study on the subject, and could rise further after separate research that clears up some of the remaining doubts.
Three studies published in Nature and Nature Geoscience use extensive historical data to show there has never been a period in the last 2,000 years when temperature changes have been as fast and extensive as in recent decades.
It had previously been thought that similarly dramatic peaks and troughs might have occurred in the past, including in periods dubbed the Little Ice Age and the Medieval Climate Anomaly. But the three studies use reconstructions based on 700 proxy records of temperature change, such as trees, ice and sediment, from all continents that indicate none of these shifts took place in more than half the globe at any one time.
Previous shifts can be attributed to volcanic cooling. But the signal of industrial warming is now so strong and so widespread as to completely overwhelm it.
The authors naively hope that this will end climate denial. It should among actual scientists. But deniers are no longer operating in good faith, and have surrendered that title. Instead, they're just public relations mercenaries, advertisers, not scientists.