What was the relationship between vegetation and global temperatures over the past 10,000 years

While scientists focus on climate change, one expert focused his attention on how changes in vegetation influenced the planet's temperatures. What is the reason for this situation and what signs it provides for the future

Vista de un sector del Parque Nacional Coiba un conjunto de islas de origen volcánico ubicadas en el Pacífico panameño. EFE/Alejandro Bolívar

Global warming is a reality. However, throughout history there have been variations in the temperature of the planet. Now, a recent study pointed out that the fluctuations recorded during the last 10,000 years were related to changes in the flora. “Projections for future climate change are more likely to produce more reliable predictions if they include changes in vegetation,” experts said.

According to the study conducted by Alexander Thompson, a researcher of earth and planetary sciences at Arts & Sciences at the University of Washington, in St. Louis, traces of pollen allow us to know what the development of plant life was in the last 10 thousand years. These signs also tell the “true story of global temperatures,” the document noted.

The research, which was published in Science Advances, also assured that warm temperatures drove vegetation growth, and this increase was correlated with an increase in the planet's temperature . Thus, according to Thompson's simulation, significant temperature fluctuations have been recorded since the last ice age: with a peak between 6,000 and 9,000 years ago, which raised the global temperature of the planet between 0.7 and 0.8 °C.

“Pollen records suggest a large expansion of vegetation during that time,” said Thompson, who highlighted the role of changes in vegetation in favor of atmospheric carbon dioxide concentrations or the ice sheet. “The previous models show only a limited amount of vegetation growth and, although some simulations have included dynamic vegetation, this was not enough vegetation change to explain what the pollen records suggest,” he said, highlighting improvements in his analysis.

Thanks to these advances, the researcher pointed out the importance of knowing what happened in the Holocene (current geological stage), since at that time the Sahara Desert (Africa) was like a meadow; while in the middle latitudes of the northern hemisphere and the Arctic, coniferous and deciduous forests grew. “The vegetation expanded during the Holocene warmed the globe to 1.5 degrees Fahrenheit,” Thompson explained.

“It is exciting that we can point to the vegetation of the northern hemisphere as a potential factor that allows us to solve the controversial Holocene temperature conundrum,” the expert assured. As he explained, these data are the result of “pollen records”, which were analyzed along with other experiments related to climate models, including the Community Earth System Model (CESM), considered to be “one of the best-considered models”.

“In general, our study emphasizes that taking into account vegetation change is fundamental,” said the scientist. He also pointed out that understanding what the scale of vegetation growth was and knowing the time of temperature change during the Holocene, called “the most important moment in recent geological history”, will allow us to have greater knowledge of the origin of human agriculture, as well as also of the advancement of civilization during that period.

This era and the advances of human civilization that were recorded are analyzed by scientists and historians, as they will allow us to know aspects of humanity that have not yet been discovered. But that's not all, according to Thompson, this is just the starting point. Thanks to their analysis, not only will aspects of the past be known, but even “these results demonstrate that the models of the Intergovernmental Panel on Climate Change (IPCC) can simulate a realistic temperature response to external climate forcing, but only when all forcing is included relevant. Our findings imply that projections for future climate change are more likely to produce more reliable predictions if they include changes in vegetation.”

KEEP READING: