A University of Arizona-led effort conducted a research to reconstruct Earth’s climate since the last ice age, which was about 24,000 years ago. The study highlighted the main drivers of climate change and underlined how the human-caused global warming over the last 150 years has pushed the climate system.
Key Findings of the Study
The study outcome published in the journal Nature consists of the following three crucial findings:
- The study verified that the main drivers of climate change since the last ice age were rising greenhouse gas (GHG) concentrations, and the retreat of the ice sheets.
- It suggested a general warming trend over the last 10,000 years, settling a decade-long debate about whether this period trended warmer or cooler in the palaeoclimatology community.
- The magnitude and rate of warming over the last 150 years far surpassed the magnitude and rate of changes over the last 24,000 years.
The Methodology The research team created maps of global temperature changes for every 200-year interval going back 24,000 years, as part of this study. Thereafter, they combined two independent datasets to create a clearer picture of the past—temperature data from marine sediments and Computer simulations of climate. The technique of combining the methods to utilise the benefits of each is called ‘data assimilation. It is generally used in weather forecasting.)
The researchers looked at the chemical signatures of marine sediments to get information about past temperatures. Temperature changes over time can affect the chemistry of a long-dead animal’s shell. Paleo-climatologists can use those measurements to estimate the temperature in an area. However, this method cannot be relied upon due to lack of accuracy. So, the researchers combined it with computer-simulated climate models to harness the strength of each.
Thus, the scientists leveraged the relative merits of each of these unique datasets in order to generate observationally constrained, dynamically consistent, and spatially complete reconstructions of past climate change. Presently, the scientists are working on using this method to investigate climate changes that took place in the past.
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