By Daniel Garcia Casillas on March 10, 2023 at 2:49 am
Global warming remains one of the greatest challenges facing humanity. And the study of climate history could help us solve this problem.
A group of scientists recently completed a comprehensive, global assessment of our planet’s climate history to understand how the natural component of climate variability interacts with human-induced global warming.
“It is very important to understand natural climate variability to understand how global warming interacts with it,” Ellie Broadman, a postdoctoral research associate in climate science at the University of Arizona, told Metro.
To understand how Earth’s climate has worked throughout history, scientists have made a comprehensive global-scale assessment of temperature changes, including both natural records, such as tree rings and seabed sediment, as models of climate.
Using these estimates, researchers generate climate models that help explore past environments where instruments such as thermometers were not available to measure temperature.
These are examples of mathematical representations of the Earth’s climate system. They depict the relationships between the atmosphere, the biosphere and the hydrosphere to create the best possible picture of reality.
These climate models – which are used to study current conditions, predict future changes and reconstruct the past – found that the average temperature of our planet 1600 years ago was 0.7C warmer than the average of the 19th century, and has gradually cooled since then. After the industrial revolution, that trend began to reverse.
Climate models generally show a slight warming trend, corresponding to a gradual increase in carbon dioxide, as agricultural societies developed over a millennium after the retreat of the ice sheet in the Northern Hemisphere.
Researchers believe that these models, based on a large historical analysis of the Earth’s climate, can help us understand and even predict the behavior of global warming.
Metro spoke to Ellie Broadman to find out more.
The Earth’s average temperature about 6,000 years ago was a degree Celsius warmer compared to the 19th century average.
The growth rings that form every year on trees.
-Ice from the mountains
-Small shells in the sediment that accumulates over time at the ocean floor
Postdoctoral Research Associate in Climate Sciences at the University of Arizona, USA.
Q: Why is it important to study the history of heaven?
– Human-induced climate change is causing an increase in the Earth’s average surface temperature, but this trend is being superimposed by long-term natural climate variability, such as ocean patterns and atmospheric circulation. It is important to know that climate variability is a natural part of understanding how global warming interacts with it. To do this we need records that extend beyond “instrumental time” captured by thermometers and satellites, so that we can distinguish natural weather events caused by humans.
Q: How is climate change researched?
– We study long-term climate change using two main lines of evidence. It is one of the data stored in the Earth’s natural archive. If we know the relationship between the climate and the information contained in the file, we can use it as a “surrogate” to reconstruct climate change over time. The most common example is probably tree rings, the width of which changes in response to temperature and rainfall; the tree grows and creates a wider circle in growing conditions over the years. We can use climate models, which are mathematical representations of the climate system.
Q: Was the Earth already warming, or does global warming reverse the long-term cooling trend?
– Our comprehensive review of the evidence suggests that a slight cooling trend on a global scale likely occurred from ~6,500 years ago until the 19th century, when modern global warming began during the Industrial Age.
Q: And the future climate of the earth?
– Our study demonstrates the importance of regional environmental changes, such as those related to vegetation in arid regions and Arctic sea ice, in driving climate change on a global scale. Therefore, it is important that we continue to focus on representing these processes well in climate models that predict the future climate.