Fact Check: Global temperatures have not cooled but increased since the medieval time
India experienced its second hottest quarter from June to August this year since 1970,
Claim :
Earth’s climate has cooled, not gone up from the medieval timeFact :
According to the experts, the Earth had heated up since the medieval time, not cooled
India experienced its second hottest quarter from June to August this year since 1970, with more than one-third of the country’s population facing at least 7 days of scorching heat. Globally, August 2024 was recorded as the Earth’s hottest August, marking the 15th consecutive month of record-high global temperatures. There are several evidences that temperatures are increasing globally.
Meanwhile, a Facebook post sharing a quote from an Australian geologist and professor emeritus at the University of Melbourne, Ian Plimer claims that the global temperatures are not increasing, but have decreased about 4 degrees, if we measure from medieval times. The post claims to be the quote from Professor Ian Plimer: The question of whether or not the planet is warming up is entirely dependent on when you start measuring. “If you started measuring in the 1850s, there’s been a general warming of about 0.7 degrees Celsius… if you started to measure from the medieval times, we’ve had a cooling of about four degrees Celsius… so if you are telling me that the planet’s warming, my question is, since when?”
Here are the post links shared online.
Fact check:
The claim is False. Earth has not cooled 4 degrees since the medieval times.
According to a Reuters report, the European Union’s Copernicus Climate Change Service (C3S) confirmed that 2023 has been the hottest year in the global temperature records going back to 1850. On an average, in 2023, the planet was 1.48 degrees Celsius hotter than in the 1850-1900 pre-industrial period, when humans began burning fossil fuels on an industrial scale, pumping carbon dioxide into the atmosphere.
Here is the Copernicus data from the year 2023.
NASA’s report shares a graph showing the change in the global surface temperature compared to the long-term average from 1951 to 1980. The earth’s average surface temperature in 2023 was the warmest on record since recordkeeping began in 1880. Overall, Earth was about 2.45 degrees Fahrenheit or 1.36 degrees Celsius warmer in 2023 than in the late 19th century (1850 -1900) preindustrial average.
A study published in Nature states that looking at climate change from the past 24,000 years, global temperatures have slightly risen since the Holocene.
Prof Plimer has made other claims that have been debunked by few fact check organisations previously. Alan Mix, a professor of earth, ocean, atmospheric sciences at Oregon State University, told the AAP fact check that on global average, the temperatures have been increasing from the early to mid- Holocene periods, the statement that the temperatures have decreased is not true.
The scientific studies show that the global temperatures have risen gradually over the years. The claim that the temperatures have decreased about 4 degrees since medieval times is False.
