The Earth was the warmest between 1971 and 2000 in 1,400 years, a new study has revealed. According to the first continental-scale reconstruction of the temperatures over the past 2,000 years by an international team of scientists, the Earth’s climate warmed more during these years than any other three-decade interval in 1,400 years.
The study states that greenhouse gases emitted from industries were responsible for the increase in temperatures, which continues even today. “This period of manmade global warming reversed a natural cooling trend that lasted several hundred years,” stated the study published in Nature Geoscience on Tuesday.
Conducted by more than 80 scientists from 24 countries including the Indian Institute of Tropical Meteorology at Pune, the study analysed climate data from tree rings, pollen, cave formations, ice cores, lake and ocean sediments, and historical records from around the world.
India’s contribution to the study was data on tree rings in the Himalayan region – tree rings get broad during warm weather and narrow when cold. “The tree rings reflect the impact of changes in the climate on vegetation,” said scientist Hemant Borgaonkar from Indian Institute of Tropical Meteorology, Pune.
The average global temperature in the 20th century was 0.4C higher than that of the previous 500 years except for Antarctica.
“If we went into another medieval warm period again, that extra warmth would be added on top of warming from greenhouse gases,” said Edward Cook, co-author of the study and a tree-ring scientist at Lamont-Doherty Earth Observatory who led the Asia reconstruction.
“From the analysis, it shows that man-made global warming has continued after the year 2000,” said Borgaonkar.