Global warming has undone 6,500 years of worldwide cooling in the last 150 years

Caused primarily by the burning of fossil fuels global warming circulates carbon dioxide (CO2), methane and other greenhouse gases into the atmosphere and is leading to the gradual heating of Earth's surface, oceans and atmosphere.

A new study has surfaced suggesting that global warming has toppled six millennia of global cooling in the last 150 years.

The research has been published in Nature Research's Scientific Data, titled "Holocene global mean surface temperature, a multi-method reconstruction approach."

The findings of the study show that global cooling started approximately 6,500 years ago when the long-term average global temperature peaked at around 0.7 degree Celsius warmer than the mid-nineteenth century. Since then, accelerating greenhouse gases have contributed to global average temperatures that are now moving past one degree Celsius above the mid-19th century.

The study was led by four researchers of Northern Arizona University's School of Earth and Sustainability (SES). They worked in collaboration with scientists from research institutions all over the world to reconstruct the global average temperature over the Holocene Epoch -- the period following the Ice Age and beginning about 12,000 years ago.

"Previous work has shown convincingly that the world naturally and slowly cooled for at least 1,000 years prior to the middle of the 19th century when the global average temperature reversed course along with the build-up of greenhouse gases,” said Darrell Kaufman, lead author of the study.

The researchers attributed the global cooling slow cycles in the Earth's orbit, which reduced the amount of summer sunlight in the Northern Hemisphere, culminating in the 'Little Ice Age' of recent centuries.

According to Science Daily, an international group of 93 paleoclimate scientists from 23 countries earlier this year published the most comprehensive set of paleoclimate data ever compiled for the past 12,000 years. They did it by compressing 1,319 data records based on samples taken from 679 sites globally. As a result of this, now scientists across the world have access to the global database.

"Our future climate will largely depend on the influence of human factors, especially the build-up of greenhouse gases. However, the future climate will also be influenced by natural factors,” said Kaufman.